From 69747bc86f066a4c25d8a8c84ce303afcc400d23 Mon Sep 17 00:00:00 2001
From: Jan <jsteemann@users.noreply.github.com>
Date: Wed, 16 Oct 2019 18:19:57 +0200
Subject: [PATCH] Bug fix 3.4/disallow subqueries in prune (#10266)

* backport of #10231

* added derived files
---
 CHANGELOG                                  |    5 +
 arangod/Aql/Ast.cpp                        |   17 +
 arangod/Aql/Ast.h                          |    3 +
 arangod/Aql/AstNode.h                      |    1 +
 arangod/Aql/grammar.cpp                    | 1192 ++++++++++----------
 arangod/Aql/grammar.h                      |   12 +-
 arangod/Aql/grammar.hpp                    |   12 +-
 arangod/Aql/grammar.y                      |   12 +-
 tests/js/server/aql/aql-graph-traverser.js |   14 +
 9 files changed, 671 insertions(+), 597 deletions(-)

diff --git a/CHANGELOG b/CHANGELOG
index e01e4e3000..849ae20695 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -1,6 +1,11 @@
 v3.4.9 (XXX-XX-XX)
 -------------------
 
+* Disallow the usage of subqueries inside AQL traversal PRUNE conditions.
+  Using subqueries inside PRUNE conditions causes undefined behavior,
+  so such queries will now be aborted early on with a parse error 
+  instead of running into undefined behavior.
+
 * Fixed search not working in document view while in code mode.
 
 * Fixed issue #10090: fix repeatable seek to the same document in
diff --git a/arangod/Aql/Ast.cpp b/arangod/Aql/Ast.cpp
index 4a5b7fa070..2d41bcd563 100644
--- a/arangod/Aql/Ast.cpp
+++ b/arangod/Aql/Ast.cpp
@@ -743,6 +743,23 @@ AstNode* Ast::createNodeReference(Variable const* variable) {
   return node;
 }
 
+/// @brief create an AST subquery reference node
+AstNode* Ast::createNodeSubqueryReference(std::string const& variableName) {
+  AstNode* node = createNode(NODE_TYPE_REFERENCE);
+  node->setFlag(AstNodeFlagType::FLAG_SUBQUERY_REFERENCE);
+
+  auto variable = _scopes.getVariable(variableName);
+
+  if (variable == nullptr) {
+    THROW_ARANGO_EXCEPTION_MESSAGE(TRI_ERROR_INTERNAL,
+                                   "variable not found in reference AstNode");
+  }
+
+  node->setData(variable);
+
+  return node;
+}
+
 /// @brief create an AST variable access
 AstNode* Ast::createNodeAccess(Variable const* variable,
                                std::vector<basics::AttributeName> const& field) {
diff --git a/arangod/Aql/Ast.h b/arangod/Aql/Ast.h
index d20ff8a87f..8b96a16f80 100644
--- a/arangod/Aql/Ast.h
+++ b/arangod/Aql/Ast.h
@@ -246,6 +246,9 @@ class Ast {
   /// @brief create an AST reference node
   AstNode* createNodeReference(Variable const* variable);
 
+  /// @brief create an AST subquery reference node
+  AstNode* createNodeSubqueryReference(std::string const& variableName);
+
   /// @brief create an AST parameter node for a value literal
   AstNode* createNodeParameter(char const* name, size_t length);
 
diff --git a/arangod/Aql/AstNode.h b/arangod/Aql/AstNode.h
index 3d35b50478..a596b7db2b 100644
--- a/arangod/Aql/AstNode.h
+++ b/arangod/Aql/AstNode.h
@@ -71,6 +71,7 @@ enum AstNodeFlagType : AstNodeFlagsType {
   FLAG_KEEP_VARIABLENAME = 0x0010000,  // node is a reference to a variable name, not the variable value (used in KEEP nodes)
   FLAG_BIND_PARAMETER = 0x0020000,     // node was created from a bind parameter
   FLAG_FINALIZED = 0x0040000,  // node has been finalized and should not be modified; only set and checked in maintainer mode
+  FLAG_SUBQUERY_REFERENCE = 0x0080000,  // node references a subquery
 };
 
 /// @brief enumeration of AST node value types
diff --git a/arangod/Aql/grammar.cpp b/arangod/Aql/grammar.cpp
index 45547c1a0f..6566e11613 100644
--- a/arangod/Aql/grammar.cpp
+++ b/arangod/Aql/grammar.cpp
@@ -1,8 +1,9 @@
-/* A Bison parser, made by GNU Bison 3.0.4.  */
+/* A Bison parser, made by GNU Bison 3.3.2.  */
 
 /* Bison implementation for Yacc-like parsers in C
 
-   Copyright (C) 1984, 1989-1990, 2000-2015 Free Software Foundation, Inc.
+   Copyright (C) 1984, 1989-1990, 2000-2015, 2018-2019 Free Software Foundation,
+   Inc.
 
    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
@@ -40,11 +41,14 @@
    define necessary library symbols; they are noted "INFRINGES ON
    USER NAME SPACE" below.  */
 
+/* Undocumented macros, especially those whose name start with YY_,
+   are private implementation details.  Do not rely on them.  */
+
 /* Identify Bison output.  */
 #define YYBISON 1
 
 /* Bison version.  */
-#define YYBISON_VERSION "3.0.4"
+#define YYBISON_VERSION "3.3.2"
 
 /* Skeleton name.  */
 #define YYSKELETON_NAME "yacc.c"
@@ -67,8 +71,8 @@
 #define yynerrs         Aqlnerrs
 
 
-/* Copy the first part of user declarations.  */
-#line 9 "Aql/grammar.y" /* yacc.c:339  */
+/* First part of user prologue.  */
+#line 9 "Aql/grammar.y" /* yacc.c:337  */
 
 // we are using alloca here explicitly because we may
 // otherwise leak error messages that are generated by Bison.
@@ -93,13 +97,16 @@
 #include "Transaction/Context.h"
 #include "VocBase/AccessMode.h"
 
-#line 97 "Aql/grammar.cpp" /* yacc.c:339  */
-
+#line 101 "Aql/grammar.cpp" /* yacc.c:337  */
 # ifndef YY_NULLPTR
-#  if defined __cplusplus && 201103L <= __cplusplus
-#   define YY_NULLPTR nullptr
+#  if defined __cplusplus
+#   if 201103L <= __cplusplus
+#    define YY_NULLPTR nullptr
+#   else
+#    define YY_NULLPTR 0
+#   endif
 #  else
-#   define YY_NULLPTR 0
+#   define YY_NULLPTR ((void*)0)
 #  endif
 # endif
 
@@ -208,7 +215,7 @@ extern int Aqldebug;
 
 union YYSTYPE
 {
-#line 34 "Aql/grammar.y" /* yacc.c:355  */
+#line 34 "Aql/grammar.y" /* yacc.c:352  */
 
   arangodb::aql::AstNode*  node;
   struct {
@@ -218,7 +225,7 @@ union YYSTYPE
   bool                     boolval;
   int64_t                  intval;
 
-#line 222 "Aql/grammar.cpp" /* yacc.c:355  */
+#line 229 "Aql/grammar.cpp" /* yacc.c:352  */
 };
 
 typedef union YYSTYPE YYSTYPE;
@@ -246,8 +253,8 @@ int Aqlparse (arangodb::aql::Parser* parser);
 
 #endif /* !YY_AQL_AQL_GRAMMAR_HPP_INCLUDED  */
 
-/* Copy the second part of user declarations.  */
-#line 44 "Aql/grammar.y" /* yacc.c:358  */
+/* Second part of user prologue.  */
+#line 44 "Aql/grammar.y" /* yacc.c:354  */
 
 
 using namespace arangodb::aql;
@@ -418,7 +425,7 @@ static AstNode* TransformOutputVariables(Parser* parser, AstNode const* names) {
 }
 
 
-#line 422 "Aql/grammar.cpp" /* yacc.c:358  */
+#line 429 "Aql/grammar.cpp" /* yacc.c:354  */
 
 #ifdef short
 # undef short
@@ -439,13 +446,13 @@ typedef signed char yytype_int8;
 #ifdef YYTYPE_UINT16
 typedef YYTYPE_UINT16 yytype_uint16;
 #else
-typedef unsigned short int yytype_uint16;
+typedef unsigned short yytype_uint16;
 #endif
 
 #ifdef YYTYPE_INT16
 typedef YYTYPE_INT16 yytype_int16;
 #else
-typedef short int yytype_int16;
+typedef short yytype_int16;
 #endif
 
 #ifndef YYSIZE_T
@@ -457,7 +464,7 @@ typedef short int yytype_int16;
 #  include <stddef.h> /* INFRINGES ON USER NAME SPACE */
 #  define YYSIZE_T size_t
 # else
-#  define YYSIZE_T unsigned int
+#  define YYSIZE_T unsigned
 # endif
 #endif
 
@@ -493,15 +500,6 @@ typedef short int yytype_int16;
 # define YY_ATTRIBUTE_UNUSED YY_ATTRIBUTE ((__unused__))
 #endif
 
-#if !defined _Noreturn \
-     && (!defined __STDC_VERSION__ || __STDC_VERSION__ < 201112)
-# if defined _MSC_VER && 1200 <= _MSC_VER
-#  define _Noreturn __declspec (noreturn)
-# else
-#  define _Noreturn YY_ATTRIBUTE ((__noreturn__))
-# endif
-#endif
-
 /* Suppress unused-variable warnings by "using" E.  */
 #if ! defined lint || defined __GNUC__
 # define YYUSE(E) ((void) (E))
@@ -509,7 +507,7 @@ typedef short int yytype_int16;
 # define YYUSE(E) /* empty */
 #endif
 
-#if defined __GNUC__ && 407 <= __GNUC__ * 100 + __GNUC_MINOR__
+#if defined __GNUC__ && ! defined __ICC && 407 <= __GNUC__ * 100 + __GNUC_MINOR__
 /* Suppress an incorrect diagnostic about yylval being uninitialized.  */
 # define YY_IGNORE_MAYBE_UNINITIALIZED_BEGIN \
     _Pragma ("GCC diagnostic push") \
@@ -673,16 +671,16 @@ union yyalloc
 /* YYNSTATES -- Number of states.  */
 #define YYNSTATES  372
 
-/* YYTRANSLATE[YYX] -- Symbol number corresponding to YYX as returned
-   by yylex, with out-of-bounds checking.  */
 #define YYUNDEFTOK  2
 #define YYMAXUTOK   328
 
+/* YYTRANSLATE(TOKEN-NUM) -- Symbol number corresponding to TOKEN-NUM
+   as returned by yylex, with out-of-bounds checking.  */
 #define YYTRANSLATE(YYX)                                                \
-  ((unsigned int) (YYX) <= YYMAXUTOK ? yytranslate[YYX] : YYUNDEFTOK)
+  ((unsigned) (YYX) <= YYMAXUTOK ? yytranslate[YYX] : YYUNDEFTOK)
 
 /* YYTRANSLATE[TOKEN-NUM] -- Symbol number corresponding to TOKEN-NUM
-   as returned by yylex, without out-of-bounds checking.  */
+   as returned by yylex.  */
 static const yytype_uint8 yytranslate[] =
 {
        0,     2,     2,     2,     2,     2,     2,     2,     2,     2,
@@ -727,26 +725,26 @@ static const yytype_uint16 yyrline[] =
        0,   389,   389,   392,   405,   409,   413,   420,   422,   422,
      434,   439,   444,   446,   449,   452,   455,   458,   464,   466,
      471,   473,   475,   477,   479,   481,   483,   485,   487,   489,
-     491,   496,   503,   510,   516,   523,   550,   574,   587,   612,
-     612,   670,   670,   693,   714,   722,   727,   729,   734,   741,
-     751,   751,   765,   774,   786,   810,   866,   885,   912,   914,
-     919,   926,   929,   932,   941,   955,   972,   972,   986,   986,
-     996,   996,  1007,  1010,  1016,  1022,  1025,  1028,  1031,  1037,
-    1042,  1049,  1057,  1060,  1066,  1076,  1086,  1094,  1105,  1110,
-    1118,  1129,  1134,  1137,  1143,  1147,  1143,  1199,  1202,  1205,
-    1211,  1211,  1221,  1227,  1230,  1233,  1236,  1239,  1242,  1248,
-    1251,  1267,  1267,  1276,  1276,  1286,  1289,  1292,  1298,  1301,
-    1304,  1307,  1310,  1313,  1316,  1319,  1322,  1325,  1328,  1331,
-    1334,  1337,  1340,  1343,  1349,  1355,  1362,  1365,  1368,  1371,
-    1374,  1377,  1380,  1383,  1389,  1392,  1398,  1400,  1405,  1408,
-    1408,  1424,  1427,  1433,  1436,  1442,  1442,  1451,  1453,  1458,
-    1461,  1467,  1470,  1496,  1516,  1519,  1533,  1533,  1542,  1544,
-    1549,  1551,  1556,  1570,  1574,  1583,  1590,  1593,  1599,  1602,
-    1608,  1611,  1614,  1620,  1623,  1629,  1632,  1635,  1639,  1645,
-    1649,  1656,  1662,  1662,  1671,  1675,  1684,  1687,  1690,  1696,
-    1699,  1705,  1738,  1741,  1744,  1751,  1761,  1761,  1774,  1789,
-    1803,  1817,  1817,  1860,  1863,  1869,  1876,  1886,  1889,  1892,
-    1895,  1898,  1904,  1908,  1912,  1922,  1929,  1935,  1938,  1943
+     491,   496,   503,   510,   516,   523,   550,   573,   586,   611,
+     611,   669,   669,   701,   722,   730,   735,   737,   742,   749,
+     759,   759,   773,   782,   794,   818,   874,   893,   920,   922,
+     927,   934,   937,   940,   949,   963,   980,   980,   994,   994,
+    1004,  1004,  1015,  1018,  1024,  1030,  1033,  1036,  1039,  1045,
+    1050,  1057,  1065,  1068,  1074,  1084,  1094,  1102,  1113,  1118,
+    1126,  1137,  1142,  1145,  1151,  1155,  1151,  1207,  1210,  1213,
+    1219,  1219,  1229,  1235,  1238,  1241,  1244,  1247,  1250,  1256,
+    1259,  1275,  1275,  1284,  1284,  1294,  1297,  1300,  1306,  1309,
+    1312,  1315,  1318,  1321,  1324,  1327,  1330,  1333,  1336,  1339,
+    1342,  1345,  1348,  1351,  1357,  1363,  1370,  1373,  1376,  1379,
+    1382,  1385,  1388,  1391,  1397,  1400,  1406,  1408,  1413,  1416,
+    1416,  1432,  1435,  1441,  1444,  1450,  1450,  1459,  1461,  1466,
+    1469,  1475,  1478,  1504,  1524,  1527,  1541,  1541,  1550,  1552,
+    1557,  1559,  1564,  1578,  1582,  1591,  1598,  1601,  1607,  1610,
+    1616,  1619,  1622,  1628,  1631,  1637,  1640,  1643,  1647,  1653,
+    1657,  1664,  1670,  1670,  1679,  1683,  1692,  1695,  1698,  1704,
+    1707,  1713,  1746,  1749,  1752,  1759,  1769,  1769,  1782,  1797,
+    1811,  1825,  1825,  1868,  1871,  1877,  1884,  1894,  1897,  1900,
+    1903,  1906,  1912,  1916,  1920,  1930,  1937,  1943,  1946,  1951
 };
 #endif
 
@@ -1376,22 +1374,22 @@ static const yytype_uint8 yyr2[] =
 
 #define YYRECOVERING()  (!!yyerrstatus)
 
-#define YYBACKUP(Token, Value)                                  \
-do                                                              \
-  if (yychar == YYEMPTY)                                        \
-    {                                                           \
-      yychar = (Token);                                         \
-      yylval = (Value);                                         \
-      YYPOPSTACK (yylen);                                       \
-      yystate = *yyssp;                                         \
-      goto yybackup;                                            \
-    }                                                           \
-  else                                                          \
-    {                                                           \
-      yyerror (&yylloc, parser, YY_("syntax error: cannot back up")); \
-      YYERROR;                                                  \
-    }                                                           \
-while (0)
+#define YYBACKUP(Token, Value)                                    \
+  do                                                              \
+    if (yychar == YYEMPTY)                                        \
+      {                                                           \
+        yychar = (Token);                                         \
+        yylval = (Value);                                         \
+        YYPOPSTACK (yylen);                                       \
+        yystate = *yyssp;                                         \
+        goto yybackup;                                            \
+      }                                                           \
+    else                                                          \
+      {                                                           \
+        yyerror (&yylloc, parser, YY_("syntax error: cannot back up")); \
+        YYERROR;                                                  \
+      }                                                           \
+  while (0)
 
 /* Error token number */
 #define YYTERROR        1
@@ -1450,10 +1448,10 @@ do {                                            \
 /* Print *YYLOCP on YYO.  Private, do not rely on its existence. */
 
 YY_ATTRIBUTE_UNUSED
-static unsigned
+static int
 yy_location_print_ (FILE *yyo, YYLTYPE const * const yylocp)
 {
-  unsigned res = 0;
+  int res = 0;
   int end_col = 0 != yylocp->last_column ? yylocp->last_column - 1 : 0;
   if (0 <= yylocp->first_line)
     {
@@ -1496,41 +1494,41 @@ do {                                                                      \
 } while (0)
 
 
-/*----------------------------------------.
-| Print this symbol's value on YYOUTPUT.  |
-`----------------------------------------*/
+/*-----------------------------------.
+| Print this symbol's value on YYO.  |
+`-----------------------------------*/
 
 static void
-yy_symbol_value_print (FILE *yyoutput, int yytype, YYSTYPE const * const yyvaluep, YYLTYPE const * const yylocationp, arangodb::aql::Parser* parser)
+yy_symbol_value_print (FILE *yyo, int yytype, YYSTYPE const * const yyvaluep, YYLTYPE const * const yylocationp, arangodb::aql::Parser* parser)
 {
-  FILE *yyo = yyoutput;
-  YYUSE (yyo);
+  FILE *yyoutput = yyo;
+  YYUSE (yyoutput);
   YYUSE (yylocationp);
   YYUSE (parser);
   if (!yyvaluep)
     return;
 # ifdef YYPRINT
   if (yytype < YYNTOKENS)
-    YYPRINT (yyoutput, yytoknum[yytype], *yyvaluep);
+    YYPRINT (yyo, yytoknum[yytype], *yyvaluep);
 # endif
   YYUSE (yytype);
 }
 
 
-/*--------------------------------.
-| Print this symbol on YYOUTPUT.  |
-`--------------------------------*/
+/*---------------------------.
+| Print this symbol on YYO.  |
+`---------------------------*/
 
 static void
-yy_symbol_print (FILE *yyoutput, int yytype, YYSTYPE const * const yyvaluep, YYLTYPE const * const yylocationp, arangodb::aql::Parser* parser)
+yy_symbol_print (FILE *yyo, int yytype, YYSTYPE const * const yyvaluep, YYLTYPE const * const yylocationp, arangodb::aql::Parser* parser)
 {
-  YYFPRINTF (yyoutput, "%s %s (",
+  YYFPRINTF (yyo, "%s %s (",
              yytype < YYNTOKENS ? "token" : "nterm", yytname[yytype]);
 
-  YY_LOCATION_PRINT (yyoutput, *yylocationp);
-  YYFPRINTF (yyoutput, ": ");
-  yy_symbol_value_print (yyoutput, yytype, yyvaluep, yylocationp, parser);
-  YYFPRINTF (yyoutput, ")");
+  YY_LOCATION_PRINT (yyo, *yylocationp);
+  YYFPRINTF (yyo, ": ");
+  yy_symbol_value_print (yyo, yytype, yyvaluep, yylocationp, parser);
+  YYFPRINTF (yyo, ")");
 }
 
 /*------------------------------------------------------------------.
@@ -1564,7 +1562,7 @@ do {                                                            \
 static void
 yy_reduce_print (yytype_int16 *yyssp, YYSTYPE *yyvsp, YYLTYPE *yylsp, int yyrule, arangodb::aql::Parser* parser)
 {
-  unsigned long int yylno = yyrline[yyrule];
+  unsigned long yylno = yyrline[yyrule];
   int yynrhs = yyr2[yyrule];
   int yyi;
   YYFPRINTF (stderr, "Reducing stack by rule %d (line %lu):\n",
@@ -1575,7 +1573,7 @@ yy_reduce_print (yytype_int16 *yyssp, YYSTYPE *yyvsp, YYLTYPE *yylsp, int yyrule
       YYFPRINTF (stderr, "   $%d = ", yyi + 1);
       yy_symbol_print (stderr,
                        yystos[yyssp[yyi + 1 - yynrhs]],
-                       &(yyvsp[(yyi + 1) - (yynrhs)])
+                       &yyvsp[(yyi + 1) - (yynrhs)]
                        , &(yylsp[(yyi + 1) - (yynrhs)])                       , parser);
       YYFPRINTF (stderr, "\n");
     }
@@ -1679,7 +1677,10 @@ yytnamerr (char *yyres, const char *yystr)
           case '\\':
             if (*++yyp != '\\')
               goto do_not_strip_quotes;
-            /* Fall through.  */
+            else
+              goto append;
+
+          append:
           default:
             if (yyres)
               yyres[yyn] = *yyp;
@@ -1697,7 +1698,7 @@ yytnamerr (char *yyres, const char *yystr)
   if (! yyres)
     return yystrlen (yystr);
 
-  return yystpcpy (yyres, yystr) - yyres;
+  return (YYSIZE_T) (yystpcpy (yyres, yystr) - yyres);
 }
 # endif
 
@@ -1775,10 +1776,10 @@ yysyntax_error (YYSIZE_T *yymsg_alloc, char **yymsg,
                 yyarg[yycount++] = yytname[yyx];
                 {
                   YYSIZE_T yysize1 = yysize + yytnamerr (YY_NULLPTR, yytname[yyx]);
-                  if (! (yysize <= yysize1
-                         && yysize1 <= YYSTACK_ALLOC_MAXIMUM))
+                  if (yysize <= yysize1 && yysize1 <= YYSTACK_ALLOC_MAXIMUM)
+                    yysize = yysize1;
+                  else
                     return 2;
-                  yysize = yysize1;
                 }
               }
         }
@@ -1790,6 +1791,7 @@ yysyntax_error (YYSIZE_T *yymsg_alloc, char **yymsg,
       case N:                               \
         yyformat = S;                       \
       break
+    default: /* Avoid compiler warnings. */
       YYCASE_(0, YY_("syntax error"));
       YYCASE_(1, YY_("syntax error, unexpected %s"));
       YYCASE_(2, YY_("syntax error, unexpected %s, expecting %s"));
@@ -1801,9 +1803,10 @@ yysyntax_error (YYSIZE_T *yymsg_alloc, char **yymsg,
 
   {
     YYSIZE_T yysize1 = yysize + yystrlen (yyformat);
-    if (! (yysize <= yysize1 && yysize1 <= YYSTACK_ALLOC_MAXIMUM))
+    if (yysize <= yysize1 && yysize1 <= YYSTACK_ALLOC_MAXIMUM)
+      yysize = yysize1;
+    else
       return 2;
-    yysize = yysize1;
   }
 
   if (*yymsg_alloc < yysize)
@@ -1955,23 +1958,31 @@ YYLTYPE yylloc = yyloc_default;
   yylsp[0] = yylloc;
   goto yysetstate;
 
+
 /*------------------------------------------------------------.
-| yynewstate -- Push a new state, which is found in yystate.  |
+| yynewstate -- push a new state, which is found in yystate.  |
 `------------------------------------------------------------*/
- yynewstate:
+yynewstate:
   /* In all cases, when you get here, the value and location stacks
      have just been pushed.  So pushing a state here evens the stacks.  */
   yyssp++;
 
- yysetstate:
-  *yyssp = yystate;
+
+/*--------------------------------------------------------------------.
+| yynewstate -- set current state (the top of the stack) to yystate.  |
+`--------------------------------------------------------------------*/
+yysetstate:
+  *yyssp = (yytype_int16) yystate;
 
   if (yyss + yystacksize - 1 <= yyssp)
+#if !defined yyoverflow && !defined YYSTACK_RELOCATE
+    goto yyexhaustedlab;
+#else
     {
       /* Get the current used size of the three stacks, in elements.  */
-      YYSIZE_T yysize = yyssp - yyss + 1;
+      YYSIZE_T yysize = (YYSIZE_T) (yyssp - yyss + 1);
 
-#ifdef yyoverflow
+# if defined yyoverflow
       {
         /* Give user a chance to reallocate the stack.  Use copies of
            these so that the &'s don't force the real ones into
@@ -1989,15 +2000,11 @@ YYLTYPE yylloc = yyloc_default;
                     &yyvs1, yysize * sizeof (*yyvsp),
                     &yyls1, yysize * sizeof (*yylsp),
                     &yystacksize);
-
-        yyls = yyls1;
         yyss = yyss1;
         yyvs = yyvs1;
+        yyls = yyls1;
       }
-#else /* no yyoverflow */
-# ifndef YYSTACK_RELOCATE
-      goto yyexhaustedlab;
-# else
+# else /* defined YYSTACK_RELOCATE */
       /* Extend the stack our own way.  */
       if (YYMAXDEPTH <= yystacksize)
         goto yyexhaustedlab;
@@ -2014,23 +2021,23 @@ YYLTYPE yylloc = yyloc_default;
         YYSTACK_RELOCATE (yyss_alloc, yyss);
         YYSTACK_RELOCATE (yyvs_alloc, yyvs);
         YYSTACK_RELOCATE (yyls_alloc, yyls);
-#  undef YYSTACK_RELOCATE
+# undef YYSTACK_RELOCATE
         if (yyss1 != yyssa)
           YYSTACK_FREE (yyss1);
       }
 # endif
-#endif /* no yyoverflow */
 
       yyssp = yyss + yysize - 1;
       yyvsp = yyvs + yysize - 1;
       yylsp = yyls + yysize - 1;
 
       YYDPRINTF ((stderr, "Stack size increased to %lu\n",
-                  (unsigned long int) yystacksize));
+                  (unsigned long) yystacksize));
 
       if (yyss + yystacksize - 1 <= yyssp)
         YYABORT;
     }
+#endif /* !defined yyoverflow && !defined YYSTACK_RELOCATE */
 
   YYDPRINTF ((stderr, "Entering state %d\n", yystate));
 
@@ -2039,11 +2046,11 @@ YYLTYPE yylloc = yyloc_default;
 
   goto yybackup;
 
+
 /*-----------.
 | yybackup.  |
 `-----------*/
 yybackup:
-
   /* Do appropriate processing given the current state.  Read a
      lookahead token if we need one and don't already have one.  */
 
@@ -2116,7 +2123,7 @@ yydefault:
 
 
 /*-----------------------------.
-| yyreduce -- Do a reduction.  |
+| yyreduce -- do a reduction.  |
 `-----------------------------*/
 yyreduce:
   /* yyn is the number of a rule to reduce with.  */
@@ -2132,21 +2139,22 @@ yyreduce:
      GCC warning that YYVAL may be used uninitialized.  */
   yyval = yyvsp[1-yylen];
 
-  /* Default location.  */
+  /* Default location. */
   YYLLOC_DEFAULT (yyloc, (yylsp - yylen), yylen);
+  yyerror_range[1] = yyloc;
   YY_REDUCE_PRINT (yyn);
   switch (yyn)
     {
         case 2:
-#line 389 "Aql/grammar.y" /* yacc.c:1646  */
+#line 389 "Aql/grammar.y" /* yacc.c:1652  */
     {
       (yyval.node) = parser->ast()->createNodeValueString((yyvsp[0].strval).value, (yyvsp[0].strval).length);
     }
-#line 2146 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 2154 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 3:
-#line 392 "Aql/grammar.y" /* yacc.c:1646  */
+#line 392 "Aql/grammar.y" /* yacc.c:1652  */
     {
       char const* p = (yyvsp[0].node)->getStringValue();
       size_t const len = (yyvsp[0].node)->getStringLength();
@@ -2157,217 +2165,217 @@ yyreduce:
 
       (yyval.node) = (yyvsp[0].node);
     }
-#line 2161 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 2169 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 4:
-#line 405 "Aql/grammar.y" /* yacc.c:1646  */
+#line 405 "Aql/grammar.y" /* yacc.c:1652  */
     {
        auto node = static_cast<AstNode*>(parser->peekStack());
        node->addMember((yyvsp[0].node));
      }
-#line 2170 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 2178 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 5:
-#line 409 "Aql/grammar.y" /* yacc.c:1646  */
+#line 409 "Aql/grammar.y" /* yacc.c:1652  */
     {
        auto node = static_cast<AstNode*>(parser->peekStack());
        node->addMember((yyvsp[0].node));
      }
-#line 2179 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 2187 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 6:
-#line 413 "Aql/grammar.y" /* yacc.c:1646  */
+#line 413 "Aql/grammar.y" /* yacc.c:1652  */
     {
        auto node = static_cast<AstNode*>(parser->peekStack());
        node->addMember((yyvsp[0].node));
      }
-#line 2188 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 2196 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 7:
-#line 420 "Aql/grammar.y" /* yacc.c:1646  */
+#line 420 "Aql/grammar.y" /* yacc.c:1652  */
     {
      }
-#line 2195 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 2203 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 8:
-#line 422 "Aql/grammar.y" /* yacc.c:1646  */
+#line 422 "Aql/grammar.y" /* yacc.c:1652  */
     {
       auto node = parser->ast()->createNodeArray();
       parser->pushStack(node);
      }
-#line 2204 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 2212 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 9:
-#line 425 "Aql/grammar.y" /* yacc.c:1646  */
+#line 425 "Aql/grammar.y" /* yacc.c:1652  */
     {
       auto node = static_cast<AstNode*>(parser->popStack());
       auto const& resolver = parser->query()->resolver();
       auto withNode = parser->ast()->createNodeWithCollections(node, resolver);
       parser->ast()->addOperation(withNode);
      }
-#line 2215 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 2223 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 10:
-#line 434 "Aql/grammar.y" /* yacc.c:1646  */
+#line 434 "Aql/grammar.y" /* yacc.c:1652  */
     {
     }
-#line 2222 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 2230 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 11:
-#line 439 "Aql/grammar.y" /* yacc.c:1646  */
+#line 439 "Aql/grammar.y" /* yacc.c:1652  */
     {
     }
-#line 2229 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 2237 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 12:
-#line 444 "Aql/grammar.y" /* yacc.c:1646  */
+#line 444 "Aql/grammar.y" /* yacc.c:1652  */
     {
     }
-#line 2236 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 2244 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 13:
-#line 446 "Aql/grammar.y" /* yacc.c:1646  */
+#line 446 "Aql/grammar.y" /* yacc.c:1652  */
     {
       parser->ast()->scopes()->endNested();
     }
-#line 2244 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 2252 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 14:
-#line 449 "Aql/grammar.y" /* yacc.c:1646  */
+#line 449 "Aql/grammar.y" /* yacc.c:1652  */
     {
       parser->ast()->scopes()->endNested();
     }
-#line 2252 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 2260 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 15:
-#line 452 "Aql/grammar.y" /* yacc.c:1646  */
+#line 452 "Aql/grammar.y" /* yacc.c:1652  */
     {
       parser->ast()->scopes()->endNested();
     }
-#line 2260 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 2268 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 16:
-#line 455 "Aql/grammar.y" /* yacc.c:1646  */
+#line 455 "Aql/grammar.y" /* yacc.c:1652  */
     {
       parser->ast()->scopes()->endNested();
     }
-#line 2268 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 2276 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 17:
-#line 458 "Aql/grammar.y" /* yacc.c:1646  */
+#line 458 "Aql/grammar.y" /* yacc.c:1652  */
     {
       parser->ast()->scopes()->endNested();
     }
-#line 2276 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 2284 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 18:
-#line 464 "Aql/grammar.y" /* yacc.c:1646  */
+#line 464 "Aql/grammar.y" /* yacc.c:1652  */
     {
     }
-#line 2283 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 2291 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 19:
-#line 466 "Aql/grammar.y" /* yacc.c:1646  */
+#line 466 "Aql/grammar.y" /* yacc.c:1652  */
     {
     }
-#line 2290 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 2298 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 20:
-#line 471 "Aql/grammar.y" /* yacc.c:1646  */
+#line 471 "Aql/grammar.y" /* yacc.c:1652  */
     {
     }
-#line 2297 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 2305 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 21:
-#line 473 "Aql/grammar.y" /* yacc.c:1646  */
+#line 473 "Aql/grammar.y" /* yacc.c:1652  */
     {
     }
-#line 2304 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 2312 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 22:
-#line 475 "Aql/grammar.y" /* yacc.c:1646  */
+#line 475 "Aql/grammar.y" /* yacc.c:1652  */
     {
     }
-#line 2311 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 2319 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 23:
-#line 477 "Aql/grammar.y" /* yacc.c:1646  */
+#line 477 "Aql/grammar.y" /* yacc.c:1652  */
     {
     }
-#line 2318 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 2326 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 24:
-#line 479 "Aql/grammar.y" /* yacc.c:1646  */
+#line 479 "Aql/grammar.y" /* yacc.c:1652  */
     {
     }
-#line 2325 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 2333 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 25:
-#line 481 "Aql/grammar.y" /* yacc.c:1646  */
+#line 481 "Aql/grammar.y" /* yacc.c:1652  */
     {
     }
-#line 2332 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 2340 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 26:
-#line 483 "Aql/grammar.y" /* yacc.c:1646  */
+#line 483 "Aql/grammar.y" /* yacc.c:1652  */
     {
     }
-#line 2339 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 2347 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 27:
-#line 485 "Aql/grammar.y" /* yacc.c:1646  */
+#line 485 "Aql/grammar.y" /* yacc.c:1652  */
     {
     }
-#line 2346 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 2354 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 28:
-#line 487 "Aql/grammar.y" /* yacc.c:1646  */
+#line 487 "Aql/grammar.y" /* yacc.c:1652  */
     {
     }
-#line 2353 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 2361 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 29:
-#line 489 "Aql/grammar.y" /* yacc.c:1646  */
+#line 489 "Aql/grammar.y" /* yacc.c:1652  */
     {
     }
-#line 2360 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 2368 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 30:
-#line 491 "Aql/grammar.y" /* yacc.c:1646  */
+#line 491 "Aql/grammar.y" /* yacc.c:1652  */
     {
     }
-#line 2367 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 2375 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 31:
-#line 496 "Aql/grammar.y" /* yacc.c:1646  */
+#line 496 "Aql/grammar.y" /* yacc.c:1652  */
     {
       auto wrapperNode = parser->ast()->createNodeArray();
       parser->pushArray(wrapperNode);
@@ -2375,28 +2383,28 @@ yyreduce:
       AstNode* node = parser->ast()->createNodeValueString((yyvsp[0].strval).value, (yyvsp[0].strval).length);
       parser->pushArrayElement(node);
     }
-#line 2379 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 2387 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 32:
-#line 503 "Aql/grammar.y" /* yacc.c:1646  */
+#line 503 "Aql/grammar.y" /* yacc.c:1652  */
     {
       AstNode* node = parser->ast()->createNodeValueString((yyvsp[0].strval).value, (yyvsp[0].strval).length);
       parser->pushArrayElement(node);
     }
-#line 2388 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 2396 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 33:
-#line 510 "Aql/grammar.y" /* yacc.c:1646  */
+#line 510 "Aql/grammar.y" /* yacc.c:1652  */
     {
       (yyval.node) = parser->popArray();
     }
-#line 2396 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 2404 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 34:
-#line 516 "Aql/grammar.y" /* yacc.c:1646  */
+#line 516 "Aql/grammar.y" /* yacc.c:1652  */
     {
       auto node = static_cast<AstNode*>(parser->peekStack());
       // Prune
@@ -2404,11 +2412,11 @@ yyreduce:
       // Options
       node->addMember(parser->ast()->createNodeNop());
     }
-#line 2408 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 2416 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 35:
-#line 523 "Aql/grammar.y" /* yacc.c:1646  */
+#line 523 "Aql/grammar.y" /* yacc.c:1652  */
     {
       auto node = static_cast<AstNode*>(parser->peekStack());
       if (TRI_CaseEqualString((yyvsp[-1].strval).value, "PRUNE")) {
@@ -2436,11 +2444,11 @@ yyreduce:
         parser->registerParseError(TRI_ERROR_QUERY_PARSE, "unexpected qualifier '%s', expecting 'PRUNE' or 'OPTIONS'", (yyvsp[-1].strval).value, yylloc.first_line, yylloc.first_column);
       }
     }
-#line 2440 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 2448 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 36:
-#line 550 "Aql/grammar.y" /* yacc.c:1646  */
+#line 550 "Aql/grammar.y" /* yacc.c:1652  */
     {
       /* prune and options */
       auto node = static_cast<AstNode*>(parser->peekStack());
@@ -2460,13 +2468,12 @@ yyreduce:
       node->addMember((yyvsp[-2].node));
       // Options
       node->addMember((yyvsp[0].node));
-
     }
-#line 2466 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 2473 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 37:
-#line 574 "Aql/grammar.y" /* yacc.c:1646  */
+#line 573 "Aql/grammar.y" /* yacc.c:1652  */
     {
       auto infoNode = parser->ast()->createNodeArray();
       // Direction
@@ -2477,11 +2484,11 @@ yyreduce:
       infoNode->addMember((yyvsp[0].node));
       (yyval.node) = infoNode;
     }
-#line 2481 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 2488 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 38:
-#line 587 "Aql/grammar.y" /* yacc.c:1646  */
+#line 586 "Aql/grammar.y" /* yacc.c:1652  */
     {
       if (!TRI_CaseEqualString((yyvsp[-3].strval).value, "TO")) {
         parser->registerParseError(TRI_ERROR_QUERY_PARSE, "unexpected qualifier '%s', expecting 'TO'", (yyvsp[-3].strval).value, yylloc.first_line, yylloc.first_column);
@@ -2502,11 +2509,11 @@ yyreduce:
       infoNode->addMember(opts);
       (yyval.node) = infoNode;
     }
-#line 2506 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 2513 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 39:
-#line 612 "Aql/grammar.y" /* yacc.c:1646  */
+#line 611 "Aql/grammar.y" /* yacc.c:1652  */
     {
       // first open a new scope (after expression is evaluated)
       parser->ast()->scopes()->start(arangodb::aql::AQL_SCOPE_FOR);
@@ -2526,11 +2533,11 @@ yyreduce:
 
       parser->pushStack(variableNode);
     }
-#line 2530 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 2537 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 40:
-#line 630 "Aql/grammar.y" /* yacc.c:1646  */
+#line 629 "Aql/grammar.y" /* yacc.c:1652  */
     {
       // now we can handle the optional SEARCH condition and OPTIONS.
       AstNode* variableNode = static_cast<AstNode*>(parser->popStack());
@@ -2571,11 +2578,11 @@ yyreduce:
         
       parser->ast()->addOperation(node);
     }
-#line 2575 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 2582 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 41:
-#line 670 "Aql/grammar.y" /* yacc.c:1646  */
+#line 669 "Aql/grammar.y" /* yacc.c:1652  */
     {
       // first open a new scope (after expression is evaluated)
       parser->ast()->scopes()->start(arangodb::aql::AQL_SCOPE_FOR);
@@ -2594,22 +2601,31 @@ yyreduce:
       parser->pushStack(graphInfoNode);
       // This stack push/pop magic is necessary to allow v, e, and p in the prune condition
     }
-#line 2598 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 2605 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 42:
-#line 687 "Aql/grammar.y" /* yacc.c:1646  */
+#line 686 "Aql/grammar.y" /* yacc.c:1652  */
     {
       auto graphInfoNode = static_cast<AstNode*>(parser->popStack());
       auto variablesNode = static_cast<AstNode*>(parser->popStack());
+
+      auto prune = graphInfoNode->getMember(3);
+      if (prune != nullptr) {
+        Ast::traverseReadOnly(prune, [&](AstNode const* node) {
+          if (node->type == NODE_TYPE_REFERENCE && node->hasFlag(AstNodeFlagType::FLAG_SUBQUERY_REFERENCE)) {
+            parser->registerParseError(TRI_ERROR_QUERY_PARSE, "prune condition must not use a subquery", yylloc.first_line, yylloc.first_column);
+          }
+        });
+      }
       auto node = parser->ast()->createNodeTraversal(variablesNode, graphInfoNode);
       parser->ast()->addOperation(node);
     }
-#line 2609 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 2625 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 43:
-#line 693 "Aql/grammar.y" /* yacc.c:1646  */
+#line 701 "Aql/grammar.y" /* yacc.c:1652  */
     {
       // first open a new scope (after expression is evaluated)
       parser->ast()->scopes()->start(arangodb::aql::AQL_SCOPE_FOR);
@@ -2628,51 +2644,51 @@ yyreduce:
       parser->ast()->addOperation(node);
  
     }
-#line 2632 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 2648 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 44:
-#line 714 "Aql/grammar.y" /* yacc.c:1646  */
+#line 722 "Aql/grammar.y" /* yacc.c:1652  */
     {
       // operand is a reference. can use it directly
       auto node = parser->ast()->createNodeFilter((yyvsp[0].node));
       parser->ast()->addOperation(node);
     }
-#line 2642 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 2658 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 45:
-#line 722 "Aql/grammar.y" /* yacc.c:1646  */
+#line 730 "Aql/grammar.y" /* yacc.c:1652  */
     {
     }
-#line 2649 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 2665 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 46:
-#line 727 "Aql/grammar.y" /* yacc.c:1646  */
+#line 735 "Aql/grammar.y" /* yacc.c:1652  */
     {
     }
-#line 2656 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 2672 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 47:
-#line 729 "Aql/grammar.y" /* yacc.c:1646  */
+#line 737 "Aql/grammar.y" /* yacc.c:1652  */
     {
     }
-#line 2663 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 2679 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 48:
-#line 734 "Aql/grammar.y" /* yacc.c:1646  */
+#line 742 "Aql/grammar.y" /* yacc.c:1652  */
     {
       auto node = parser->ast()->createNodeLet((yyvsp[-2].strval).value, (yyvsp[-2].strval).length, (yyvsp[0].node), true);
       parser->ast()->addOperation(node);
     }
-#line 2672 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 2688 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 49:
-#line 741 "Aql/grammar.y" /* yacc.c:1646  */
+#line 749 "Aql/grammar.y" /* yacc.c:1652  */
     {
       if (!TRI_CaseEqualString((yyvsp[-2].strval).value, "COUNT")) {
         parser->registerParseError(TRI_ERROR_QUERY_PARSE, "unexpected qualifier '%s', expecting 'COUNT'", (yyvsp[-2].strval).value, yylloc.first_line, yylloc.first_column);
@@ -2680,20 +2696,20 @@ yyreduce:
 
       (yyval.strval) = (yyvsp[0].strval);
     }
-#line 2684 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 2700 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 50:
-#line 751 "Aql/grammar.y" /* yacc.c:1646  */
+#line 759 "Aql/grammar.y" /* yacc.c:1652  */
     {
       auto node = parser->ast()->createNodeArray();
       parser->pushStack(node);
     }
-#line 2693 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 2709 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 51:
-#line 754 "Aql/grammar.y" /* yacc.c:1646  */
+#line 762 "Aql/grammar.y" /* yacc.c:1652  */
     {
       auto list = static_cast<AstNode*>(parser->popStack());
 
@@ -2702,11 +2718,11 @@ yyreduce:
       }
       (yyval.node) = list;
     }
-#line 2706 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 2722 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 52:
-#line 765 "Aql/grammar.y" /* yacc.c:1646  */
+#line 773 "Aql/grammar.y" /* yacc.c:1652  */
     {
       /* COLLECT WITH COUNT INTO var OPTIONS ... */
       auto scopes = parser->ast()->scopes();
@@ -2716,11 +2732,11 @@ yyreduce:
       auto node = parser->ast()->createNodeCollectCount(parser->ast()->createNodeArray(), (yyvsp[-1].strval).value, (yyvsp[-1].strval).length, (yyvsp[0].node));
       parser->ast()->addOperation(node);
     }
-#line 2720 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 2736 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 53:
-#line 774 "Aql/grammar.y" /* yacc.c:1646  */
+#line 782 "Aql/grammar.y" /* yacc.c:1652  */
     {
       /* COLLECT var = expr WITH COUNT INTO var OPTIONS ... */
       auto scopes = parser->ast()->scopes();
@@ -2733,11 +2749,11 @@ yyreduce:
       auto node = parser->ast()->createNodeCollectCount((yyvsp[-2].node), (yyvsp[-1].strval).value, (yyvsp[-1].strval).length, (yyvsp[0].node));
       parser->ast()->addOperation(node);
     }
-#line 2737 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 2753 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 54:
-#line 786 "Aql/grammar.y" /* yacc.c:1646  */
+#line 794 "Aql/grammar.y" /* yacc.c:1652  */
     {
       /* AGGREGATE var = expr OPTIONS ... */
       std::unordered_set<Variable const*> variablesIntroduced;
@@ -2762,11 +2778,11 @@ yyreduce:
       auto node = parser->ast()->createNodeCollect(parser->ast()->createNodeArray(), (yyvsp[-2].node), into, intoExpression, nullptr, (yyvsp[-1].node));
       parser->ast()->addOperation(node);
     }
-#line 2766 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 2782 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 55:
-#line 810 "Aql/grammar.y" /* yacc.c:1646  */
+#line 818 "Aql/grammar.y" /* yacc.c:1652  */
     {
       /* COLLECT var = expr AGGREGATE var = expr OPTIONS ... */
       std::unordered_set<Variable const*> variablesIntroduced;
@@ -2823,11 +2839,11 @@ yyreduce:
       auto node = parser->ast()->createNodeCollect((yyvsp[-3].node), (yyvsp[-2].node), into, intoExpression, nullptr, (yyvsp[0].node));
       parser->ast()->addOperation(node);
     }
-#line 2827 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 2843 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 56:
-#line 866 "Aql/grammar.y" /* yacc.c:1646  */
+#line 874 "Aql/grammar.y" /* yacc.c:1652  */
     {
       /* COLLECT var = expr INTO var OPTIONS ... */
       std::unordered_set<Variable const*> variablesIntroduced;
@@ -2847,11 +2863,11 @@ yyreduce:
       auto node = parser->ast()->createNodeCollect((yyvsp[-2].node), parser->ast()->createNodeArray(), into, intoExpression, nullptr, (yyvsp[0].node));
       parser->ast()->addOperation(node);
     }
-#line 2851 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 2867 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 57:
-#line 885 "Aql/grammar.y" /* yacc.c:1646  */
+#line 893 "Aql/grammar.y" /* yacc.c:1652  */
     {
       /* COLLECT var = expr INTO var KEEP ... OPTIONS ... */
       std::unordered_set<Variable const*> variablesIntroduced;
@@ -2876,61 +2892,61 @@ yyreduce:
       auto node = parser->ast()->createNodeCollect((yyvsp[-3].node), parser->ast()->createNodeArray(), into, intoExpression, (yyvsp[-1].node), (yyvsp[0].node));
       parser->ast()->addOperation(node);
     }
-#line 2880 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 2896 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 58:
-#line 912 "Aql/grammar.y" /* yacc.c:1646  */
+#line 920 "Aql/grammar.y" /* yacc.c:1652  */
     {
     }
-#line 2887 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 2903 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 59:
-#line 914 "Aql/grammar.y" /* yacc.c:1646  */
+#line 922 "Aql/grammar.y" /* yacc.c:1652  */
     {
     }
-#line 2894 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 2910 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 60:
-#line 919 "Aql/grammar.y" /* yacc.c:1646  */
+#line 927 "Aql/grammar.y" /* yacc.c:1652  */
     {
       auto node = parser->ast()->createNodeAssign((yyvsp[-2].strval).value, (yyvsp[-2].strval).length, (yyvsp[0].node));
       parser->pushArrayElement(node);
     }
-#line 2903 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 2919 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 61:
-#line 926 "Aql/grammar.y" /* yacc.c:1646  */
+#line 934 "Aql/grammar.y" /* yacc.c:1652  */
     {
       (yyval.node) = nullptr;
     }
-#line 2911 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 2927 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 62:
-#line 929 "Aql/grammar.y" /* yacc.c:1646  */
+#line 937 "Aql/grammar.y" /* yacc.c:1652  */
     {
       (yyval.node) = parser->ast()->createNodeValueString((yyvsp[0].strval).value, (yyvsp[0].strval).length);
     }
-#line 2919 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 2935 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 63:
-#line 932 "Aql/grammar.y" /* yacc.c:1646  */
+#line 940 "Aql/grammar.y" /* yacc.c:1652  */
     {
       auto node = parser->ast()->createNodeArray();
       node->addMember(parser->ast()->createNodeValueString((yyvsp[-2].strval).value, (yyvsp[-2].strval).length));
       node->addMember((yyvsp[0].node));
       (yyval.node) = node;
     }
-#line 2930 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 2946 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 64:
-#line 941 "Aql/grammar.y" /* yacc.c:1646  */
+#line 949 "Aql/grammar.y" /* yacc.c:1652  */
     {
       if (! parser->ast()->scopes()->existsVariable((yyvsp[0].strval).value, (yyvsp[0].strval).length)) {
         parser->registerParseError(TRI_ERROR_QUERY_PARSE, "use of unknown variable '%s' for KEEP", (yyvsp[0].strval).value, yylloc.first_line, yylloc.first_column);
@@ -2945,11 +2961,11 @@ yyreduce:
       node->setFlag(FLAG_KEEP_VARIABLENAME);
       parser->pushArrayElement(node);
     }
-#line 2949 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 2965 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 65:
-#line 955 "Aql/grammar.y" /* yacc.c:1646  */
+#line 963 "Aql/grammar.y" /* yacc.c:1652  */
     {
       if (! parser->ast()->scopes()->existsVariable((yyvsp[0].strval).value, (yyvsp[0].strval).length)) {
         parser->registerParseError(TRI_ERROR_QUERY_PARSE, "use of unknown variable '%s' for KEEP", (yyvsp[0].strval).value, yylloc.first_line, yylloc.first_column);
@@ -2964,11 +2980,11 @@ yyreduce:
       node->setFlag(FLAG_KEEP_VARIABLENAME);
       parser->pushArrayElement(node);
     }
-#line 2968 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 2984 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 66:
-#line 972 "Aql/grammar.y" /* yacc.c:1646  */
+#line 980 "Aql/grammar.y" /* yacc.c:1652  */
     {
       if (!TRI_CaseEqualString((yyvsp[0].strval).value, "KEEP")) {
         parser->registerParseError(TRI_ERROR_QUERY_PARSE, "unexpected qualifier '%s', expecting 'KEEP'", (yyvsp[0].strval).value, yylloc.first_line, yylloc.first_column);
@@ -2977,158 +2993,158 @@ yyreduce:
       auto node = parser->ast()->createNodeArray();
       parser->pushStack(node);
     }
-#line 2981 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 2997 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 67:
-#line 979 "Aql/grammar.y" /* yacc.c:1646  */
+#line 987 "Aql/grammar.y" /* yacc.c:1652  */
     {
       auto list = static_cast<AstNode*>(parser->popStack());
       (yyval.node) = list;
     }
-#line 2990 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 3006 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 68:
-#line 986 "Aql/grammar.y" /* yacc.c:1646  */
+#line 994 "Aql/grammar.y" /* yacc.c:1652  */
     {
       auto node = parser->ast()->createNodeArray();
       parser->pushStack(node);
     }
-#line 2999 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 3015 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 69:
-#line 989 "Aql/grammar.y" /* yacc.c:1646  */
+#line 997 "Aql/grammar.y" /* yacc.c:1652  */
     {
       auto list = static_cast<AstNode*>(parser->popStack());
       (yyval.node) = list;
     }
-#line 3008 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 3024 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 70:
-#line 996 "Aql/grammar.y" /* yacc.c:1646  */
+#line 1004 "Aql/grammar.y" /* yacc.c:1652  */
     {
       auto node = parser->ast()->createNodeArray();
       parser->pushStack(node);
     }
-#line 3017 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 3033 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 71:
-#line 999 "Aql/grammar.y" /* yacc.c:1646  */
+#line 1007 "Aql/grammar.y" /* yacc.c:1652  */
     {
       auto list = static_cast<AstNode const*>(parser->popStack());
       auto node = parser->ast()->createNodeSort(list);
       parser->ast()->addOperation(node);
     }
-#line 3027 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 3043 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 72:
-#line 1007 "Aql/grammar.y" /* yacc.c:1646  */
+#line 1015 "Aql/grammar.y" /* yacc.c:1652  */
     {
       parser->pushArrayElement((yyvsp[0].node));
     }
-#line 3035 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 3051 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 73:
-#line 1010 "Aql/grammar.y" /* yacc.c:1646  */
+#line 1018 "Aql/grammar.y" /* yacc.c:1652  */
     {
       parser->pushArrayElement((yyvsp[0].node));
     }
-#line 3043 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 3059 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 74:
-#line 1016 "Aql/grammar.y" /* yacc.c:1646  */
+#line 1024 "Aql/grammar.y" /* yacc.c:1652  */
     {
       (yyval.node) = parser->ast()->createNodeSortElement((yyvsp[-1].node), (yyvsp[0].node));
     }
-#line 3051 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 3067 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 75:
-#line 1022 "Aql/grammar.y" /* yacc.c:1646  */
+#line 1030 "Aql/grammar.y" /* yacc.c:1652  */
     {
       (yyval.node) = parser->ast()->createNodeValueBool(true);
     }
-#line 3059 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 3075 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 76:
-#line 1025 "Aql/grammar.y" /* yacc.c:1646  */
+#line 1033 "Aql/grammar.y" /* yacc.c:1652  */
     {
       (yyval.node) = parser->ast()->createNodeValueBool(true);
     }
-#line 3067 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 3083 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 77:
-#line 1028 "Aql/grammar.y" /* yacc.c:1646  */
+#line 1036 "Aql/grammar.y" /* yacc.c:1652  */
     {
       (yyval.node) = parser->ast()->createNodeValueBool(false);
     }
-#line 3075 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 3091 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 78:
-#line 1031 "Aql/grammar.y" /* yacc.c:1646  */
+#line 1039 "Aql/grammar.y" /* yacc.c:1652  */
     {
       (yyval.node) = (yyvsp[0].node);
     }
-#line 3083 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 3099 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 79:
-#line 1037 "Aql/grammar.y" /* yacc.c:1646  */
+#line 1045 "Aql/grammar.y" /* yacc.c:1652  */
     {
       auto offset = parser->ast()->createNodeValueInt(0);
       auto node = parser->ast()->createNodeLimit(offset, (yyvsp[0].node));
       parser->ast()->addOperation(node);
     }
-#line 3093 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 3109 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 80:
-#line 1042 "Aql/grammar.y" /* yacc.c:1646  */
+#line 1050 "Aql/grammar.y" /* yacc.c:1652  */
     {
       auto node = parser->ast()->createNodeLimit((yyvsp[-2].node), (yyvsp[0].node));
       parser->ast()->addOperation(node);
     }
-#line 3102 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 3118 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 81:
-#line 1049 "Aql/grammar.y" /* yacc.c:1646  */
+#line 1057 "Aql/grammar.y" /* yacc.c:1652  */
     {
       auto node = parser->ast()->createNodeReturn((yyvsp[0].node));
       parser->ast()->addOperation(node);
       parser->ast()->scopes()->endNested();
     }
-#line 3112 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 3128 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 82:
-#line 1057 "Aql/grammar.y" /* yacc.c:1646  */
+#line 1065 "Aql/grammar.y" /* yacc.c:1652  */
     {
       (yyval.node) = (yyvsp[0].node);
     }
-#line 3120 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 3136 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 83:
-#line 1060 "Aql/grammar.y" /* yacc.c:1646  */
+#line 1068 "Aql/grammar.y" /* yacc.c:1652  */
     {
        (yyval.node) = (yyvsp[0].node);
      }
-#line 3128 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 3144 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 84:
-#line 1066 "Aql/grammar.y" /* yacc.c:1646  */
+#line 1074 "Aql/grammar.y" /* yacc.c:1652  */
     {
       if (!parser->configureWriteQuery((yyvsp[-1].node), (yyvsp[0].node))) {
         YYABORT;
@@ -3136,11 +3152,11 @@ yyreduce:
       auto node = parser->ast()->createNodeRemove((yyvsp[-2].node), (yyvsp[-1].node), (yyvsp[0].node));
       parser->ast()->addOperation(node);
     }
-#line 3140 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 3156 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 85:
-#line 1076 "Aql/grammar.y" /* yacc.c:1646  */
+#line 1084 "Aql/grammar.y" /* yacc.c:1652  */
     {
       if (!parser->configureWriteQuery((yyvsp[-1].node), (yyvsp[0].node))) {
         YYABORT;
@@ -3148,11 +3164,11 @@ yyreduce:
       auto node = parser->ast()->createNodeInsert((yyvsp[-2].node), (yyvsp[-1].node), (yyvsp[0].node));
       parser->ast()->addOperation(node);
     }
-#line 3152 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 3168 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 86:
-#line 1086 "Aql/grammar.y" /* yacc.c:1646  */
+#line 1094 "Aql/grammar.y" /* yacc.c:1652  */
     {
       if (!parser->configureWriteQuery((yyvsp[-1].node), (yyvsp[0].node))) {
         YYABORT;
@@ -3161,11 +3177,11 @@ yyreduce:
       AstNode* node = parser->ast()->createNodeUpdate(nullptr, (yyvsp[-2].node), (yyvsp[-1].node), (yyvsp[0].node));
       parser->ast()->addOperation(node);
     }
-#line 3165 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 3181 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 87:
-#line 1094 "Aql/grammar.y" /* yacc.c:1646  */
+#line 1102 "Aql/grammar.y" /* yacc.c:1652  */
     {
       if (!parser->configureWriteQuery((yyvsp[-1].node), (yyvsp[0].node))) {
         YYABORT;
@@ -3174,18 +3190,18 @@ yyreduce:
       AstNode* node = parser->ast()->createNodeUpdate((yyvsp[-4].node), (yyvsp[-2].node), (yyvsp[-1].node), (yyvsp[0].node));
       parser->ast()->addOperation(node);
     }
-#line 3178 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 3194 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 88:
-#line 1105 "Aql/grammar.y" /* yacc.c:1646  */
+#line 1113 "Aql/grammar.y" /* yacc.c:1652  */
     {
     }
-#line 3185 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 3201 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 89:
-#line 1110 "Aql/grammar.y" /* yacc.c:1646  */
+#line 1118 "Aql/grammar.y" /* yacc.c:1652  */
     {
       if (!parser->configureWriteQuery((yyvsp[-1].node), (yyvsp[0].node))) {
         YYABORT;
@@ -3194,11 +3210,11 @@ yyreduce:
       AstNode* node = parser->ast()->createNodeReplace(nullptr, (yyvsp[-2].node), (yyvsp[-1].node), (yyvsp[0].node));
       parser->ast()->addOperation(node);
     }
-#line 3198 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 3214 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 90:
-#line 1118 "Aql/grammar.y" /* yacc.c:1646  */
+#line 1126 "Aql/grammar.y" /* yacc.c:1652  */
     {
       if (!parser->configureWriteQuery((yyvsp[-1].node), (yyvsp[0].node))) {
         YYABORT;
@@ -3207,44 +3223,44 @@ yyreduce:
       AstNode* node = parser->ast()->createNodeReplace((yyvsp[-4].node), (yyvsp[-2].node), (yyvsp[-1].node), (yyvsp[0].node));
       parser->ast()->addOperation(node);
     }
-#line 3211 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 3227 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 91:
-#line 1129 "Aql/grammar.y" /* yacc.c:1646  */
+#line 1137 "Aql/grammar.y" /* yacc.c:1652  */
     {
     }
-#line 3218 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 3234 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 92:
-#line 1134 "Aql/grammar.y" /* yacc.c:1646  */
+#line 1142 "Aql/grammar.y" /* yacc.c:1652  */
     {
       (yyval.intval) = static_cast<int64_t>(NODE_TYPE_UPDATE);
     }
-#line 3226 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 3242 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 93:
-#line 1137 "Aql/grammar.y" /* yacc.c:1646  */
+#line 1145 "Aql/grammar.y" /* yacc.c:1652  */
     {
       (yyval.intval) = static_cast<int64_t>(NODE_TYPE_REPLACE);
     }
-#line 3234 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 3250 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 94:
-#line 1143 "Aql/grammar.y" /* yacc.c:1646  */
+#line 1151 "Aql/grammar.y" /* yacc.c:1652  */
     {
       // reserve a variable named "$OLD", we might need it in the update expression
       // and in a later return thing
       parser->pushStack(parser->ast()->createNodeVariable(TRI_CHAR_LENGTH_PAIR(Variable::NAME_OLD), true));
     }
-#line 3244 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 3260 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 95:
-#line 1147 "Aql/grammar.y" /* yacc.c:1646  */
+#line 1155 "Aql/grammar.y" /* yacc.c:1652  */
     {
       AstNode* variableNode = static_cast<AstNode*>(parser->popStack());
 
@@ -3284,11 +3300,11 @@ yyreduce:
       
       parser->pushStack(forNode);
     }
-#line 3288 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 3304 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 96:
-#line 1185 "Aql/grammar.y" /* yacc.c:1646  */
+#line 1193 "Aql/grammar.y" /* yacc.c:1652  */
     {
       AstNode* forNode = static_cast<AstNode*>(parser->popStack());
       forNode->changeMember(1, (yyvsp[-1].node)); 
@@ -3300,35 +3316,35 @@ yyreduce:
       auto node = parser->ast()->createNodeUpsert(static_cast<AstNodeType>((yyvsp[-3].intval)), parser->ast()->createNodeReference(TRI_CHAR_LENGTH_PAIR(Variable::NAME_OLD)), (yyvsp[-4].node), (yyvsp[-2].node), (yyvsp[-1].node), (yyvsp[0].node));
       parser->ast()->addOperation(node);
     }
-#line 3304 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 3320 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 97:
-#line 1199 "Aql/grammar.y" /* yacc.c:1646  */
+#line 1207 "Aql/grammar.y" /* yacc.c:1652  */
     {
       (yyval.node) = parser->ast()->createNodeQuantifier(Quantifier::ALL);
     }
-#line 3312 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 3328 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 98:
-#line 1202 "Aql/grammar.y" /* yacc.c:1646  */
+#line 1210 "Aql/grammar.y" /* yacc.c:1652  */
     {
       (yyval.node) = parser->ast()->createNodeQuantifier(Quantifier::ANY);
     }
-#line 3320 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 3336 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 99:
-#line 1205 "Aql/grammar.y" /* yacc.c:1646  */
+#line 1213 "Aql/grammar.y" /* yacc.c:1652  */
     {
       (yyval.node) = parser->ast()->createNodeQuantifier(Quantifier::NONE);
     }
-#line 3328 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 3344 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 100:
-#line 1211 "Aql/grammar.y" /* yacc.c:1646  */
+#line 1219 "Aql/grammar.y" /* yacc.c:1652  */
     {
       auto const scopeType = parser->ast()->scopes()->type();
 
@@ -3337,83 +3353,83 @@ yyreduce:
         parser->registerParseError(TRI_ERROR_QUERY_PARSE, "cannot use DISTINCT modifier on top-level query element", yylloc.first_line, yylloc.first_column);
       }
     }
-#line 3341 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 3357 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 101:
-#line 1218 "Aql/grammar.y" /* yacc.c:1646  */
+#line 1226 "Aql/grammar.y" /* yacc.c:1652  */
     {
       (yyval.node) = parser->ast()->createNodeDistinct((yyvsp[0].node));
     }
-#line 3349 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 3365 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 102:
-#line 1221 "Aql/grammar.y" /* yacc.c:1646  */
+#line 1229 "Aql/grammar.y" /* yacc.c:1652  */
     {
       (yyval.node) = (yyvsp[0].node);
     }
-#line 3357 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 3373 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 103:
-#line 1227 "Aql/grammar.y" /* yacc.c:1646  */
+#line 1235 "Aql/grammar.y" /* yacc.c:1652  */
     {
       (yyval.node) = (yyvsp[0].node);
     }
-#line 3365 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 3381 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 104:
-#line 1230 "Aql/grammar.y" /* yacc.c:1646  */
+#line 1238 "Aql/grammar.y" /* yacc.c:1652  */
     {
       (yyval.node) = (yyvsp[0].node);
     }
-#line 3373 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 3389 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 105:
-#line 1233 "Aql/grammar.y" /* yacc.c:1646  */
+#line 1241 "Aql/grammar.y" /* yacc.c:1652  */
     {
       (yyval.node) = (yyvsp[0].node);
     }
-#line 3381 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 3397 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 106:
-#line 1236 "Aql/grammar.y" /* yacc.c:1646  */
+#line 1244 "Aql/grammar.y" /* yacc.c:1652  */
     {
       (yyval.node) = (yyvsp[0].node);
     }
-#line 3389 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 3405 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 107:
-#line 1239 "Aql/grammar.y" /* yacc.c:1646  */
+#line 1247 "Aql/grammar.y" /* yacc.c:1652  */
     {
       (yyval.node) = (yyvsp[0].node);
     }
-#line 3397 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 3413 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 108:
-#line 1242 "Aql/grammar.y" /* yacc.c:1646  */
+#line 1250 "Aql/grammar.y" /* yacc.c:1652  */
     {
       (yyval.node) = parser->ast()->createNodeRange((yyvsp[-2].node), (yyvsp[0].node));
     }
-#line 3405 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 3421 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 109:
-#line 1248 "Aql/grammar.y" /* yacc.c:1646  */
+#line 1256 "Aql/grammar.y" /* yacc.c:1652  */
     {
       (yyval.strval) = (yyvsp[0].strval);
     }
-#line 3413 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 3429 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 110:
-#line 1251 "Aql/grammar.y" /* yacc.c:1646  */
+#line 1259 "Aql/grammar.y" /* yacc.c:1652  */
     {
       std::string temp((yyvsp[-2].strval).value, (yyvsp[-2].strval).length);
       temp.append("::");
@@ -3427,215 +3443,215 @@ yyreduce:
       (yyval.strval).value = p;
       (yyval.strval).length = temp.size();
     }
-#line 3431 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 3447 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 111:
-#line 1267 "Aql/grammar.y" /* yacc.c:1646  */
+#line 1275 "Aql/grammar.y" /* yacc.c:1652  */
     {
       parser->pushStack((yyvsp[-1].strval).value);
 
       auto node = parser->ast()->createNodeArray();
       parser->pushStack(node);
     }
-#line 3442 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 3458 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 112:
-#line 1272 "Aql/grammar.y" /* yacc.c:1646  */
+#line 1280 "Aql/grammar.y" /* yacc.c:1652  */
     {
       auto list = static_cast<AstNode const*>(parser->popStack());
       (yyval.node) = parser->ast()->createNodeFunctionCall(static_cast<char const*>(parser->popStack()), list);
     }
-#line 3451 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 3467 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 113:
-#line 1276 "Aql/grammar.y" /* yacc.c:1646  */
+#line 1284 "Aql/grammar.y" /* yacc.c:1652  */
     {
       auto node = parser->ast()->createNodeArray();
       parser->pushStack(node);
     }
-#line 3460 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 3476 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 114:
-#line 1279 "Aql/grammar.y" /* yacc.c:1646  */
+#line 1287 "Aql/grammar.y" /* yacc.c:1652  */
     {
       auto list = static_cast<AstNode const*>(parser->popStack());
       (yyval.node) = parser->ast()->createNodeFunctionCall(TRI_CHAR_LENGTH_PAIR("LIKE"), list);
     }
-#line 3469 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 3485 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 115:
-#line 1286 "Aql/grammar.y" /* yacc.c:1646  */
+#line 1294 "Aql/grammar.y" /* yacc.c:1652  */
     {
       (yyval.node) = parser->ast()->createNodeUnaryOperator(NODE_TYPE_OPERATOR_UNARY_PLUS, (yyvsp[0].node));
     }
-#line 3477 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 3493 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 116:
-#line 1289 "Aql/grammar.y" /* yacc.c:1646  */
+#line 1297 "Aql/grammar.y" /* yacc.c:1652  */
     {
       (yyval.node) = parser->ast()->createNodeUnaryOperator(NODE_TYPE_OPERATOR_UNARY_MINUS, (yyvsp[0].node));
     }
-#line 3485 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 3501 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 117:
-#line 1292 "Aql/grammar.y" /* yacc.c:1646  */
+#line 1300 "Aql/grammar.y" /* yacc.c:1652  */
     {
       (yyval.node) = parser->ast()->createNodeUnaryOperator(NODE_TYPE_OPERATOR_UNARY_NOT, (yyvsp[0].node));
     }
-#line 3493 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 3509 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 118:
-#line 1298 "Aql/grammar.y" /* yacc.c:1646  */
+#line 1306 "Aql/grammar.y" /* yacc.c:1652  */
     {
       (yyval.node) = parser->ast()->createNodeBinaryOperator(NODE_TYPE_OPERATOR_BINARY_OR, (yyvsp[-2].node), (yyvsp[0].node));
     }
-#line 3501 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 3517 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 119:
-#line 1301 "Aql/grammar.y" /* yacc.c:1646  */
+#line 1309 "Aql/grammar.y" /* yacc.c:1652  */
     {
       (yyval.node) = parser->ast()->createNodeBinaryOperator(NODE_TYPE_OPERATOR_BINARY_AND, (yyvsp[-2].node), (yyvsp[0].node));
     }
-#line 3509 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 3525 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 120:
-#line 1304 "Aql/grammar.y" /* yacc.c:1646  */
+#line 1312 "Aql/grammar.y" /* yacc.c:1652  */
     {
       (yyval.node) = parser->ast()->createNodeBinaryOperator(NODE_TYPE_OPERATOR_BINARY_PLUS, (yyvsp[-2].node), (yyvsp[0].node));
     }
-#line 3517 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 3533 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 121:
-#line 1307 "Aql/grammar.y" /* yacc.c:1646  */
+#line 1315 "Aql/grammar.y" /* yacc.c:1652  */
     {
       (yyval.node) = parser->ast()->createNodeBinaryOperator(NODE_TYPE_OPERATOR_BINARY_MINUS, (yyvsp[-2].node), (yyvsp[0].node));
     }
-#line 3525 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 3541 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 122:
-#line 1310 "Aql/grammar.y" /* yacc.c:1646  */
+#line 1318 "Aql/grammar.y" /* yacc.c:1652  */
     {
       (yyval.node) = parser->ast()->createNodeBinaryOperator(NODE_TYPE_OPERATOR_BINARY_TIMES, (yyvsp[-2].node), (yyvsp[0].node));
     }
-#line 3533 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 3549 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 123:
-#line 1313 "Aql/grammar.y" /* yacc.c:1646  */
+#line 1321 "Aql/grammar.y" /* yacc.c:1652  */
     {
       (yyval.node) = parser->ast()->createNodeBinaryOperator(NODE_TYPE_OPERATOR_BINARY_DIV, (yyvsp[-2].node), (yyvsp[0].node));
     }
-#line 3541 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 3557 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 124:
-#line 1316 "Aql/grammar.y" /* yacc.c:1646  */
+#line 1324 "Aql/grammar.y" /* yacc.c:1652  */
     {
       (yyval.node) = parser->ast()->createNodeBinaryOperator(NODE_TYPE_OPERATOR_BINARY_MOD, (yyvsp[-2].node), (yyvsp[0].node));
     }
-#line 3549 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 3565 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 125:
-#line 1319 "Aql/grammar.y" /* yacc.c:1646  */
+#line 1327 "Aql/grammar.y" /* yacc.c:1652  */
     {
       (yyval.node) = parser->ast()->createNodeBinaryOperator(NODE_TYPE_OPERATOR_BINARY_EQ, (yyvsp[-2].node), (yyvsp[0].node));
     }
-#line 3557 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 3573 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 126:
-#line 1322 "Aql/grammar.y" /* yacc.c:1646  */
+#line 1330 "Aql/grammar.y" /* yacc.c:1652  */
     {
       (yyval.node) = parser->ast()->createNodeBinaryOperator(NODE_TYPE_OPERATOR_BINARY_NE, (yyvsp[-2].node), (yyvsp[0].node));
     }
-#line 3565 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 3581 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 127:
-#line 1325 "Aql/grammar.y" /* yacc.c:1646  */
+#line 1333 "Aql/grammar.y" /* yacc.c:1652  */
     {
       (yyval.node) = parser->ast()->createNodeBinaryOperator(NODE_TYPE_OPERATOR_BINARY_LT, (yyvsp[-2].node), (yyvsp[0].node));
     }
-#line 3573 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 3589 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 128:
-#line 1328 "Aql/grammar.y" /* yacc.c:1646  */
+#line 1336 "Aql/grammar.y" /* yacc.c:1652  */
     {
       (yyval.node) = parser->ast()->createNodeBinaryOperator(NODE_TYPE_OPERATOR_BINARY_GT, (yyvsp[-2].node), (yyvsp[0].node));
     }
-#line 3581 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 3597 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 129:
-#line 1331 "Aql/grammar.y" /* yacc.c:1646  */
+#line 1339 "Aql/grammar.y" /* yacc.c:1652  */
     {
       (yyval.node) = parser->ast()->createNodeBinaryOperator(NODE_TYPE_OPERATOR_BINARY_LE, (yyvsp[-2].node), (yyvsp[0].node));
     }
-#line 3589 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 3605 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 130:
-#line 1334 "Aql/grammar.y" /* yacc.c:1646  */
+#line 1342 "Aql/grammar.y" /* yacc.c:1652  */
     {
       (yyval.node) = parser->ast()->createNodeBinaryOperator(NODE_TYPE_OPERATOR_BINARY_GE, (yyvsp[-2].node), (yyvsp[0].node));
     }
-#line 3597 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 3613 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 131:
-#line 1337 "Aql/grammar.y" /* yacc.c:1646  */
+#line 1345 "Aql/grammar.y" /* yacc.c:1652  */
     {
       (yyval.node) = parser->ast()->createNodeBinaryOperator(NODE_TYPE_OPERATOR_BINARY_IN, (yyvsp[-2].node), (yyvsp[0].node));
     }
-#line 3605 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 3621 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 132:
-#line 1340 "Aql/grammar.y" /* yacc.c:1646  */
+#line 1348 "Aql/grammar.y" /* yacc.c:1652  */
     {
       (yyval.node) = parser->ast()->createNodeBinaryOperator(NODE_TYPE_OPERATOR_BINARY_NIN, (yyvsp[-2].node), (yyvsp[0].node));
     }
-#line 3613 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 3629 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 133:
-#line 1343 "Aql/grammar.y" /* yacc.c:1646  */
+#line 1351 "Aql/grammar.y" /* yacc.c:1652  */
     {
       AstNode* arguments = parser->ast()->createNodeArray(2);
       arguments->addMember((yyvsp[-2].node));
       arguments->addMember((yyvsp[0].node));
       (yyval.node) = parser->ast()->createNodeFunctionCall(TRI_CHAR_LENGTH_PAIR("LIKE"), arguments);
     }
-#line 3624 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 3640 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 134:
-#line 1349 "Aql/grammar.y" /* yacc.c:1646  */
+#line 1357 "Aql/grammar.y" /* yacc.c:1652  */
     {
       AstNode* arguments = parser->ast()->createNodeArray(2);
       arguments->addMember((yyvsp[-2].node));
       arguments->addMember((yyvsp[0].node));
       (yyval.node) = parser->ast()->createNodeFunctionCall(TRI_CHAR_LENGTH_PAIR("REGEX_TEST"), arguments);
     }
-#line 3635 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 3651 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 135:
-#line 1355 "Aql/grammar.y" /* yacc.c:1646  */
+#line 1363 "Aql/grammar.y" /* yacc.c:1652  */
     {
       AstNode* arguments = parser->ast()->createNodeArray(2);
       arguments->addMember((yyvsp[-2].node));
@@ -3643,122 +3659,122 @@ yyreduce:
       AstNode* node = parser->ast()->createNodeFunctionCall(TRI_CHAR_LENGTH_PAIR("REGEX_TEST"), arguments);
       (yyval.node) = parser->ast()->createNodeUnaryOperator(NODE_TYPE_OPERATOR_UNARY_NOT, node);
     }
-#line 3647 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 3663 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 136:
-#line 1362 "Aql/grammar.y" /* yacc.c:1646  */
+#line 1370 "Aql/grammar.y" /* yacc.c:1652  */
     {
       (yyval.node) = parser->ast()->createNodeBinaryArrayOperator(NODE_TYPE_OPERATOR_BINARY_ARRAY_EQ, (yyvsp[-3].node), (yyvsp[0].node), (yyvsp[-2].node));
     }
-#line 3655 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 3671 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 137:
-#line 1365 "Aql/grammar.y" /* yacc.c:1646  */
+#line 1373 "Aql/grammar.y" /* yacc.c:1652  */
     {
       (yyval.node) = parser->ast()->createNodeBinaryArrayOperator(NODE_TYPE_OPERATOR_BINARY_ARRAY_NE, (yyvsp[-3].node), (yyvsp[0].node), (yyvsp[-2].node));
     }
-#line 3663 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 3679 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 138:
-#line 1368 "Aql/grammar.y" /* yacc.c:1646  */
+#line 1376 "Aql/grammar.y" /* yacc.c:1652  */
     {
       (yyval.node) = parser->ast()->createNodeBinaryArrayOperator(NODE_TYPE_OPERATOR_BINARY_ARRAY_LT, (yyvsp[-3].node), (yyvsp[0].node), (yyvsp[-2].node));
     }
-#line 3671 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 3687 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 139:
-#line 1371 "Aql/grammar.y" /* yacc.c:1646  */
+#line 1379 "Aql/grammar.y" /* yacc.c:1652  */
     {
       (yyval.node) = parser->ast()->createNodeBinaryArrayOperator(NODE_TYPE_OPERATOR_BINARY_ARRAY_GT, (yyvsp[-3].node), (yyvsp[0].node), (yyvsp[-2].node));
     }
-#line 3679 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 3695 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 140:
-#line 1374 "Aql/grammar.y" /* yacc.c:1646  */
+#line 1382 "Aql/grammar.y" /* yacc.c:1652  */
     {
       (yyval.node) = parser->ast()->createNodeBinaryArrayOperator(NODE_TYPE_OPERATOR_BINARY_ARRAY_LE, (yyvsp[-3].node), (yyvsp[0].node), (yyvsp[-2].node));
     }
-#line 3687 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 3703 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 141:
-#line 1377 "Aql/grammar.y" /* yacc.c:1646  */
+#line 1385 "Aql/grammar.y" /* yacc.c:1652  */
     {
       (yyval.node) = parser->ast()->createNodeBinaryArrayOperator(NODE_TYPE_OPERATOR_BINARY_ARRAY_GE, (yyvsp[-3].node), (yyvsp[0].node), (yyvsp[-2].node));
     }
-#line 3695 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 3711 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 142:
-#line 1380 "Aql/grammar.y" /* yacc.c:1646  */
+#line 1388 "Aql/grammar.y" /* yacc.c:1652  */
     {
       (yyval.node) = parser->ast()->createNodeBinaryArrayOperator(NODE_TYPE_OPERATOR_BINARY_ARRAY_IN, (yyvsp[-3].node), (yyvsp[0].node), (yyvsp[-2].node));
     }
-#line 3703 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 3719 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 143:
-#line 1383 "Aql/grammar.y" /* yacc.c:1646  */
+#line 1391 "Aql/grammar.y" /* yacc.c:1652  */
     {
       (yyval.node) = parser->ast()->createNodeBinaryArrayOperator(NODE_TYPE_OPERATOR_BINARY_ARRAY_NIN, (yyvsp[-3].node), (yyvsp[0].node), (yyvsp[-2].node));
     }
-#line 3711 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 3727 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 144:
-#line 1389 "Aql/grammar.y" /* yacc.c:1646  */
+#line 1397 "Aql/grammar.y" /* yacc.c:1652  */
     {
       (yyval.node) = parser->ast()->createNodeTernaryOperator((yyvsp[-4].node), (yyvsp[-2].node), (yyvsp[0].node));
     }
-#line 3719 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 3735 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 145:
-#line 1392 "Aql/grammar.y" /* yacc.c:1646  */
+#line 1400 "Aql/grammar.y" /* yacc.c:1652  */
     {
       (yyval.node) = parser->ast()->createNodeTernaryOperator((yyvsp[-3].node), (yyvsp[-3].node), (yyvsp[0].node));
     }
-#line 3727 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 3743 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 146:
-#line 1398 "Aql/grammar.y" /* yacc.c:1646  */
+#line 1406 "Aql/grammar.y" /* yacc.c:1652  */
     {
     }
-#line 3734 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 3750 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 147:
-#line 1400 "Aql/grammar.y" /* yacc.c:1646  */
+#line 1408 "Aql/grammar.y" /* yacc.c:1652  */
     {
     }
-#line 3741 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 3757 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 148:
-#line 1405 "Aql/grammar.y" /* yacc.c:1646  */
+#line 1413 "Aql/grammar.y" /* yacc.c:1652  */
     {
       (yyval.node) = (yyvsp[0].node);
     }
-#line 3749 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 3765 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 149:
-#line 1408 "Aql/grammar.y" /* yacc.c:1646  */
+#line 1416 "Aql/grammar.y" /* yacc.c:1652  */
     {
       parser->ast()->scopes()->start(arangodb::aql::AQL_SCOPE_SUBQUERY);
       parser->ast()->startSubQuery();
     }
-#line 3758 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 3774 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 150:
-#line 1411 "Aql/grammar.y" /* yacc.c:1646  */
+#line 1419 "Aql/grammar.y" /* yacc.c:1652  */
     {
       AstNode* node = parser->ast()->endSubQuery();
       parser->ast()->scopes()->endCurrent();
@@ -3767,100 +3783,100 @@ yyreduce:
       auto subQuery = parser->ast()->createNodeLet(variableName.c_str(), variableName.size(), node, false);
       parser->ast()->addOperation(subQuery);
 
-      (yyval.node) = parser->ast()->createNodeReference(variableName);
+      (yyval.node) = parser->ast()->createNodeSubqueryReference(variableName);
     }
-#line 3773 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 3789 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 151:
-#line 1424 "Aql/grammar.y" /* yacc.c:1646  */
+#line 1432 "Aql/grammar.y" /* yacc.c:1652  */
     {
       parser->pushArrayElement((yyvsp[0].node));
     }
-#line 3781 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 3797 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 152:
-#line 1427 "Aql/grammar.y" /* yacc.c:1646  */
+#line 1435 "Aql/grammar.y" /* yacc.c:1652  */
     {
       parser->pushArrayElement((yyvsp[0].node));
     }
-#line 3789 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 3805 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 153:
-#line 1433 "Aql/grammar.y" /* yacc.c:1646  */
+#line 1441 "Aql/grammar.y" /* yacc.c:1652  */
     {
       (yyval.node) = (yyvsp[0].node);
     }
-#line 3797 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 3813 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 154:
-#line 1436 "Aql/grammar.y" /* yacc.c:1646  */
+#line 1444 "Aql/grammar.y" /* yacc.c:1652  */
     {
       (yyval.node) = (yyvsp[0].node);
     }
-#line 3805 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 3821 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 155:
-#line 1442 "Aql/grammar.y" /* yacc.c:1646  */
+#line 1450 "Aql/grammar.y" /* yacc.c:1652  */
     {
       auto node = parser->ast()->createNodeArray();
       parser->pushArray(node);
     }
-#line 3814 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 3830 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 156:
-#line 1445 "Aql/grammar.y" /* yacc.c:1646  */
+#line 1453 "Aql/grammar.y" /* yacc.c:1652  */
     {
       (yyval.node) = parser->popArray();
     }
-#line 3822 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 3838 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 157:
-#line 1451 "Aql/grammar.y" /* yacc.c:1646  */
+#line 1459 "Aql/grammar.y" /* yacc.c:1652  */
     {
     }
-#line 3829 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 3845 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 158:
-#line 1453 "Aql/grammar.y" /* yacc.c:1646  */
+#line 1461 "Aql/grammar.y" /* yacc.c:1652  */
     {
     }
-#line 3836 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 3852 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 159:
-#line 1458 "Aql/grammar.y" /* yacc.c:1646  */
+#line 1466 "Aql/grammar.y" /* yacc.c:1652  */
     {
       parser->pushArrayElement((yyvsp[0].node));
     }
-#line 3844 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 3860 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 160:
-#line 1461 "Aql/grammar.y" /* yacc.c:1646  */
+#line 1469 "Aql/grammar.y" /* yacc.c:1652  */
     {
       parser->pushArrayElement((yyvsp[0].node));
     }
-#line 3852 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 3868 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 161:
-#line 1467 "Aql/grammar.y" /* yacc.c:1646  */
+#line 1475 "Aql/grammar.y" /* yacc.c:1652  */
     {
       (yyval.node) = nullptr;
     }
-#line 3860 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 3876 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 162:
-#line 1470 "Aql/grammar.y" /* yacc.c:1646  */
+#line 1478 "Aql/grammar.y" /* yacc.c:1652  */
     {
       if ((yyvsp[0].node) == nullptr) {
         ABORT_OOM
@@ -3887,11 +3903,11 @@ yyreduce:
 
       (yyval.node) = node;
     }
-#line 3891 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 3907 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 163:
-#line 1496 "Aql/grammar.y" /* yacc.c:1646  */
+#line 1504 "Aql/grammar.y" /* yacc.c:1652  */
     {
       if ((yyvsp[-2].node) == nullptr) {
         ABORT_OOM
@@ -3909,19 +3925,19 @@ yyreduce:
       node->addMember((yyvsp[0].node));
       (yyval.node) = node;
     }
-#line 3913 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 3929 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 164:
-#line 1516 "Aql/grammar.y" /* yacc.c:1646  */
+#line 1524 "Aql/grammar.y" /* yacc.c:1652  */
     {
       (yyval.node) = nullptr;
     }
-#line 3921 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 3937 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 165:
-#line 1519 "Aql/grammar.y" /* yacc.c:1646  */
+#line 1527 "Aql/grammar.y" /* yacc.c:1652  */
     {
       if ((yyvsp[0].node) == nullptr) {
         ABORT_OOM
@@ -3933,56 +3949,56 @@ yyreduce:
 
       (yyval.node) = (yyvsp[0].node);
     }
-#line 3937 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 3953 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 166:
-#line 1533 "Aql/grammar.y" /* yacc.c:1646  */
+#line 1541 "Aql/grammar.y" /* yacc.c:1652  */
     {
       auto node = parser->ast()->createNodeObject();
       parser->pushStack(node);
     }
-#line 3946 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 3962 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 167:
-#line 1536 "Aql/grammar.y" /* yacc.c:1646  */
+#line 1544 "Aql/grammar.y" /* yacc.c:1652  */
     {
       (yyval.node) = static_cast<AstNode*>(parser->popStack());
     }
-#line 3954 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 3970 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 168:
-#line 1542 "Aql/grammar.y" /* yacc.c:1646  */
+#line 1550 "Aql/grammar.y" /* yacc.c:1652  */
     {
     }
-#line 3961 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 3977 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 169:
-#line 1544 "Aql/grammar.y" /* yacc.c:1646  */
+#line 1552 "Aql/grammar.y" /* yacc.c:1652  */
     {
     }
-#line 3968 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 3984 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 170:
-#line 1549 "Aql/grammar.y" /* yacc.c:1646  */
+#line 1557 "Aql/grammar.y" /* yacc.c:1652  */
     {
     }
-#line 3975 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 3991 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 171:
-#line 1551 "Aql/grammar.y" /* yacc.c:1646  */
+#line 1559 "Aql/grammar.y" /* yacc.c:1652  */
     {
     }
-#line 3982 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 3998 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 172:
-#line 1556 "Aql/grammar.y" /* yacc.c:1646  */
+#line 1564 "Aql/grammar.y" /* yacc.c:1652  */
     {
       // attribute-name-only (comparable to JS enhanced object literals, e.g. { foo, bar })
       auto ast = parser->ast();
@@ -3997,20 +4013,20 @@ yyreduce:
       auto node = ast->createNodeReference(variable);
       parser->pushObjectElement((yyvsp[0].strval).value, (yyvsp[0].strval).length, node);
     }
-#line 4001 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 4017 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 173:
-#line 1570 "Aql/grammar.y" /* yacc.c:1646  */
+#line 1578 "Aql/grammar.y" /* yacc.c:1652  */
     {
       // attribute-name : attribute-value
       parser->pushObjectElement((yyvsp[-2].strval).value, (yyvsp[-2].strval).length, (yyvsp[0].node));
     }
-#line 4010 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 4026 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 174:
-#line 1574 "Aql/grammar.y" /* yacc.c:1646  */
+#line 1582 "Aql/grammar.y" /* yacc.c:1652  */
     {
       // bind-parameter : attribute-value
       if ((yyvsp[-2].strval).length < 1 || (yyvsp[-2].strval).value[0] == '@') {
@@ -4020,232 +4036,232 @@ yyreduce:
       auto param = parser->ast()->createNodeParameter((yyvsp[-2].strval).value, (yyvsp[-2].strval).length);
       parser->pushObjectElement(param, (yyvsp[0].node));
     }
-#line 4024 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 4040 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 175:
-#line 1583 "Aql/grammar.y" /* yacc.c:1646  */
+#line 1591 "Aql/grammar.y" /* yacc.c:1652  */
     {
       // [ attribute-name-expression ] : attribute-value
       parser->pushObjectElement((yyvsp[-3].node), (yyvsp[0].node));
     }
-#line 4033 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 4049 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 176:
-#line 1590 "Aql/grammar.y" /* yacc.c:1646  */
+#line 1598 "Aql/grammar.y" /* yacc.c:1652  */
     {
       (yyval.intval) = 1;
     }
-#line 4041 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 4057 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 177:
-#line 1593 "Aql/grammar.y" /* yacc.c:1646  */
+#line 1601 "Aql/grammar.y" /* yacc.c:1652  */
     {
       (yyval.intval) = (yyvsp[-1].intval) + 1;
     }
-#line 4049 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 4065 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 178:
-#line 1599 "Aql/grammar.y" /* yacc.c:1646  */
+#line 1607 "Aql/grammar.y" /* yacc.c:1652  */
     {
       (yyval.node) = nullptr;
     }
-#line 4057 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 4073 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 179:
-#line 1602 "Aql/grammar.y" /* yacc.c:1646  */
+#line 1610 "Aql/grammar.y" /* yacc.c:1652  */
     {
       (yyval.node) = (yyvsp[0].node);
     }
-#line 4065 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 4081 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 180:
-#line 1608 "Aql/grammar.y" /* yacc.c:1646  */
+#line 1616 "Aql/grammar.y" /* yacc.c:1652  */
     {
       (yyval.node) = nullptr;
     }
-#line 4073 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 4089 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 181:
-#line 1611 "Aql/grammar.y" /* yacc.c:1646  */
+#line 1619 "Aql/grammar.y" /* yacc.c:1652  */
     {
       (yyval.node) = parser->ast()->createNodeArrayLimit(nullptr, (yyvsp[0].node));
     }
-#line 4081 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 4097 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 182:
-#line 1614 "Aql/grammar.y" /* yacc.c:1646  */
+#line 1622 "Aql/grammar.y" /* yacc.c:1652  */
     {
       (yyval.node) = parser->ast()->createNodeArrayLimit((yyvsp[-2].node), (yyvsp[0].node));
     }
-#line 4089 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 4105 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 183:
-#line 1620 "Aql/grammar.y" /* yacc.c:1646  */
+#line 1628 "Aql/grammar.y" /* yacc.c:1652  */
     {
       (yyval.node) = nullptr;
     }
-#line 4097 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 4113 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 184:
-#line 1623 "Aql/grammar.y" /* yacc.c:1646  */
+#line 1631 "Aql/grammar.y" /* yacc.c:1652  */
     {
       (yyval.node) = (yyvsp[0].node);
     }
-#line 4105 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 4121 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 185:
-#line 1629 "Aql/grammar.y" /* yacc.c:1646  */
+#line 1637 "Aql/grammar.y" /* yacc.c:1652  */
     {
       (yyval.node) = parser->ast()->createNodeValueString((yyvsp[0].strval).value, (yyvsp[0].strval).length);
     }
-#line 4113 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 4129 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 186:
-#line 1632 "Aql/grammar.y" /* yacc.c:1646  */
+#line 1640 "Aql/grammar.y" /* yacc.c:1652  */
     {
       (yyval.node) = (yyvsp[0].node);
     }
-#line 4121 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 4137 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 187:
-#line 1635 "Aql/grammar.y" /* yacc.c:1646  */
+#line 1643 "Aql/grammar.y" /* yacc.c:1652  */
     {
       auto tmp = parser->ast()->createNodeValueString((yyvsp[0].strval).value, (yyvsp[0].strval).length);
       (yyval.node) = parser->ast()->createNodeCollectionDirection((yyvsp[-1].intval), tmp);
     }
-#line 4130 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 4146 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 188:
-#line 1639 "Aql/grammar.y" /* yacc.c:1646  */
+#line 1647 "Aql/grammar.y" /* yacc.c:1652  */
     {
       (yyval.node) = parser->ast()->createNodeCollectionDirection((yyvsp[-1].intval), (yyvsp[0].node));
     }
-#line 4138 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 4154 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 189:
-#line 1645 "Aql/grammar.y" /* yacc.c:1646  */
+#line 1653 "Aql/grammar.y" /* yacc.c:1652  */
     {
        auto node = static_cast<AstNode*>(parser->peekStack());
        node->addMember((yyvsp[0].node));
      }
-#line 4147 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 4163 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 190:
-#line 1649 "Aql/grammar.y" /* yacc.c:1646  */
+#line 1657 "Aql/grammar.y" /* yacc.c:1652  */
     {
        auto node = static_cast<AstNode*>(parser->peekStack());
        node->addMember((yyvsp[0].node));
      }
-#line 4156 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 4172 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 191:
-#line 1656 "Aql/grammar.y" /* yacc.c:1646  */
+#line 1664 "Aql/grammar.y" /* yacc.c:1652  */
     {
       auto node = parser->ast()->createNodeArray();
       node->addMember((yyvsp[0].node));
       auto const& resolver = parser->query()->resolver();
       (yyval.node) = parser->ast()->createNodeCollectionList(node, resolver);
     }
-#line 4167 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 4183 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 192:
-#line 1662 "Aql/grammar.y" /* yacc.c:1646  */
+#line 1670 "Aql/grammar.y" /* yacc.c:1652  */
     {
       auto node = parser->ast()->createNodeArray();
       parser->pushStack(node);
       node->addMember((yyvsp[-1].node));
     }
-#line 4177 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 4193 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 193:
-#line 1666 "Aql/grammar.y" /* yacc.c:1646  */
+#line 1674 "Aql/grammar.y" /* yacc.c:1652  */
     {
       auto node = static_cast<AstNode*>(parser->popStack());
       auto const& resolver = parser->query()->resolver();
       (yyval.node) = parser->ast()->createNodeCollectionList(node, resolver);
     }
-#line 4187 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 4203 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 194:
-#line 1671 "Aql/grammar.y" /* yacc.c:1646  */
+#line 1679 "Aql/grammar.y" /* yacc.c:1652  */
     {
       // graph name
       (yyval.node) = (yyvsp[0].node);
     }
-#line 4196 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 4212 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 195:
-#line 1675 "Aql/grammar.y" /* yacc.c:1646  */
+#line 1683 "Aql/grammar.y" /* yacc.c:1652  */
     {
       // graph name
       (yyval.node) = parser->ast()->createNodeValueString((yyvsp[0].strval).value, (yyvsp[0].strval).length);
     }
-#line 4205 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 4221 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 196:
-#line 1684 "Aql/grammar.y" /* yacc.c:1646  */
+#line 1692 "Aql/grammar.y" /* yacc.c:1652  */
     {
       (yyval.intval) = 2;
     }
-#line 4213 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 4229 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 197:
-#line 1687 "Aql/grammar.y" /* yacc.c:1646  */
+#line 1695 "Aql/grammar.y" /* yacc.c:1652  */
     {
       (yyval.intval) = 1;
     }
-#line 4221 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 4237 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 198:
-#line 1690 "Aql/grammar.y" /* yacc.c:1646  */
+#line 1698 "Aql/grammar.y" /* yacc.c:1652  */
     {
       (yyval.intval) = 0;
     }
-#line 4229 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 4245 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 199:
-#line 1696 "Aql/grammar.y" /* yacc.c:1646  */
+#line 1704 "Aql/grammar.y" /* yacc.c:1652  */
     {
       (yyval.node) = parser->ast()->createNodeDirection((yyvsp[0].intval), 1);
     }
-#line 4237 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 4253 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 200:
-#line 1699 "Aql/grammar.y" /* yacc.c:1646  */
+#line 1707 "Aql/grammar.y" /* yacc.c:1652  */
     {
       (yyval.node) = parser->ast()->createNodeDirection((yyvsp[0].intval), (yyvsp[-1].node));
     }
-#line 4245 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 4261 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 201:
-#line 1705 "Aql/grammar.y" /* yacc.c:1646  */
+#line 1713 "Aql/grammar.y" /* yacc.c:1652  */
     {
       // variable or collection or view
       auto ast = parser->ast();
@@ -4279,27 +4295,27 @@ yyreduce:
 
       (yyval.node) = node;
     }
-#line 4283 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 4299 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 202:
-#line 1738 "Aql/grammar.y" /* yacc.c:1646  */
+#line 1746 "Aql/grammar.y" /* yacc.c:1652  */
     {
       (yyval.node) = (yyvsp[0].node);
     }
-#line 4291 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 4307 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 203:
-#line 1741 "Aql/grammar.y" /* yacc.c:1646  */
+#line 1749 "Aql/grammar.y" /* yacc.c:1652  */
     {
       (yyval.node) = (yyvsp[0].node);
     }
-#line 4299 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 4315 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 204:
-#line 1744 "Aql/grammar.y" /* yacc.c:1646  */
+#line 1752 "Aql/grammar.y" /* yacc.c:1652  */
     {
       (yyval.node) = (yyvsp[0].node);
 
@@ -4307,11 +4323,11 @@ yyreduce:
         ABORT_OOM
       }
     }
-#line 4311 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 4327 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 205:
-#line 1751 "Aql/grammar.y" /* yacc.c:1646  */
+#line 1759 "Aql/grammar.y" /* yacc.c:1652  */
     {
       if ((yyvsp[-1].node)->type == NODE_TYPE_EXPANSION) {
         // create a dummy passthru node that reduces and evaluates the expansion first
@@ -4322,20 +4338,20 @@ yyreduce:
         (yyval.node) = (yyvsp[-1].node);
       }
     }
-#line 4326 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 4342 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 206:
-#line 1761 "Aql/grammar.y" /* yacc.c:1646  */
+#line 1769 "Aql/grammar.y" /* yacc.c:1652  */
     {
       parser->ast()->scopes()->start(arangodb::aql::AQL_SCOPE_SUBQUERY);
       parser->ast()->startSubQuery();
     }
-#line 4335 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 4351 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 207:
-#line 1764 "Aql/grammar.y" /* yacc.c:1646  */
+#line 1772 "Aql/grammar.y" /* yacc.c:1652  */
     {
       AstNode* node = parser->ast()->endSubQuery();
       parser->ast()->scopes()->endCurrent();
@@ -4346,11 +4362,11 @@ yyreduce:
 
       (yyval.node) = parser->ast()->createNodeReference(variableName);
     }
-#line 4350 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 4366 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 208:
-#line 1774 "Aql/grammar.y" /* yacc.c:1646  */
+#line 1782 "Aql/grammar.y" /* yacc.c:1652  */
     {
       // named variable access, e.g. variable.reference
       if ((yyvsp[-2].node)->type == NODE_TYPE_EXPANSION) {
@@ -4366,11 +4382,11 @@ yyreduce:
         (yyval.node) = parser->ast()->createNodeAttributeAccess((yyvsp[-2].node), (yyvsp[0].strval).value, (yyvsp[0].strval).length);
       }
     }
-#line 4370 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 4386 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 209:
-#line 1789 "Aql/grammar.y" /* yacc.c:1646  */
+#line 1797 "Aql/grammar.y" /* yacc.c:1652  */
     {
       // named variable access, e.g. variable.@reference
       if ((yyvsp[-2].node)->type == NODE_TYPE_EXPANSION) {
@@ -4385,11 +4401,11 @@ yyreduce:
         (yyval.node) = parser->ast()->createNodeBoundAttributeAccess((yyvsp[-2].node), (yyvsp[0].node));
       }
     }
-#line 4389 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 4405 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 210:
-#line 1803 "Aql/grammar.y" /* yacc.c:1646  */
+#line 1811 "Aql/grammar.y" /* yacc.c:1652  */
     {
       // indexed variable access, e.g. variable[index]
       if ((yyvsp[-3].node)->type == NODE_TYPE_EXPANSION) {
@@ -4404,11 +4420,11 @@ yyreduce:
         (yyval.node) = parser->ast()->createNodeIndexedAccess((yyvsp[-3].node), (yyvsp[-1].node));
       }
     }
-#line 4408 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 4424 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 211:
-#line 1817 "Aql/grammar.y" /* yacc.c:1646  */
+#line 1825 "Aql/grammar.y" /* yacc.c:1652  */
     {
       // variable expansion, e.g. variable[*], with optional FILTER, LIMIT and RETURN clauses
       if ((yyvsp[0].intval) > 1 && (yyvsp[-2].node)->type == NODE_TYPE_EXPANSION) {
@@ -4432,11 +4448,11 @@ yyreduce:
       auto scopes = parser->ast()->scopes();
       scopes->stackCurrentVariable(scopes->getVariable(nextName));
     }
-#line 4436 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 4452 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 212:
-#line 1839 "Aql/grammar.y" /* yacc.c:1646  */
+#line 1847 "Aql/grammar.y" /* yacc.c:1652  */
     {
       auto scopes = parser->ast()->scopes();
       scopes->unstackCurrentVariable();
@@ -4455,27 +4471,27 @@ yyreduce:
         (yyval.node) = parser->ast()->createNodeExpansion((yyvsp[-5].intval), iterator, parser->ast()->createNodeReference(variable->name), (yyvsp[-3].node), (yyvsp[-2].node), (yyvsp[-1].node));
       }
     }
-#line 4459 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 4475 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 213:
-#line 1860 "Aql/grammar.y" /* yacc.c:1646  */
+#line 1868 "Aql/grammar.y" /* yacc.c:1652  */
     {
       (yyval.node) = (yyvsp[0].node);
     }
-#line 4467 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 4483 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 214:
-#line 1863 "Aql/grammar.y" /* yacc.c:1646  */
+#line 1871 "Aql/grammar.y" /* yacc.c:1652  */
     {
       (yyval.node) = (yyvsp[0].node);
     }
-#line 4475 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 4491 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 215:
-#line 1869 "Aql/grammar.y" /* yacc.c:1646  */
+#line 1877 "Aql/grammar.y" /* yacc.c:1652  */
     {
       if ((yyvsp[0].node) == nullptr) {
         ABORT_OOM
@@ -4483,11 +4499,11 @@ yyreduce:
 
       (yyval.node) = (yyvsp[0].node);
     }
-#line 4487 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 4503 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 216:
-#line 1876 "Aql/grammar.y" /* yacc.c:1646  */
+#line 1884 "Aql/grammar.y" /* yacc.c:1652  */
     {
       if ((yyvsp[0].node) == nullptr) {
         ABORT_OOM
@@ -4495,69 +4511,69 @@ yyreduce:
 
       (yyval.node) = (yyvsp[0].node);
     }
-#line 4499 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 4515 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 217:
-#line 1886 "Aql/grammar.y" /* yacc.c:1646  */
+#line 1894 "Aql/grammar.y" /* yacc.c:1652  */
     {
       (yyval.node) = parser->ast()->createNodeValueString((yyvsp[0].strval).value, (yyvsp[0].strval).length);
     }
-#line 4507 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 4523 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 218:
-#line 1889 "Aql/grammar.y" /* yacc.c:1646  */
+#line 1897 "Aql/grammar.y" /* yacc.c:1652  */
     {
       (yyval.node) = (yyvsp[0].node);
     }
-#line 4515 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 4531 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 219:
-#line 1892 "Aql/grammar.y" /* yacc.c:1646  */
+#line 1900 "Aql/grammar.y" /* yacc.c:1652  */
     {
       (yyval.node) = parser->ast()->createNodeValueNull();
     }
-#line 4523 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 4539 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 220:
-#line 1895 "Aql/grammar.y" /* yacc.c:1646  */
+#line 1903 "Aql/grammar.y" /* yacc.c:1652  */
     {
       (yyval.node) = parser->ast()->createNodeValueBool(true);
     }
-#line 4531 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 4547 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 221:
-#line 1898 "Aql/grammar.y" /* yacc.c:1646  */
+#line 1906 "Aql/grammar.y" /* yacc.c:1652  */
     {
       (yyval.node) = parser->ast()->createNodeValueBool(false);
     }
-#line 4539 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 4555 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 222:
-#line 1904 "Aql/grammar.y" /* yacc.c:1646  */
+#line 1912 "Aql/grammar.y" /* yacc.c:1652  */
     {
       auto const& resolver = parser->query()->resolver();
       (yyval.node) = parser->ast()->createNodeCollection(resolver, (yyvsp[0].strval).value, (yyvsp[0].strval).length, arangodb::AccessMode::Type::WRITE);
     }
-#line 4548 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 4564 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 223:
-#line 1908 "Aql/grammar.y" /* yacc.c:1646  */
+#line 1916 "Aql/grammar.y" /* yacc.c:1652  */
     {
       auto const& resolver = parser->query()->resolver();
       (yyval.node) = parser->ast()->createNodeCollection(resolver, (yyvsp[0].strval).value, (yyvsp[0].strval).length, arangodb::AccessMode::Type::WRITE);
     }
-#line 4557 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 4573 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 224:
-#line 1912 "Aql/grammar.y" /* yacc.c:1646  */
+#line 1920 "Aql/grammar.y" /* yacc.c:1652  */
     {
       if ((yyvsp[0].strval).length < 2 || (yyvsp[0].strval).value[0] != '@') {
         parser->registerParseError(TRI_ERROR_QUERY_BIND_PARAMETER_TYPE, TRI_errno_string(TRI_ERROR_QUERY_BIND_PARAMETER_TYPE), (yyvsp[0].strval).value, yylloc.first_line, yylloc.first_column);
@@ -4565,11 +4581,11 @@ yyreduce:
 
       (yyval.node) = parser->ast()->createNodeParameterDatasource((yyvsp[0].strval).value, (yyvsp[0].strval).length);
     }
-#line 4569 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 4585 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 225:
-#line 1922 "Aql/grammar.y" /* yacc.c:1646  */
+#line 1930 "Aql/grammar.y" /* yacc.c:1652  */
     {
       if ((yyvsp[0].strval).length < 2 || (yyvsp[0].strval).value[0] != '@') {
         parser->registerParseError(TRI_ERROR_QUERY_BIND_PARAMETER_TYPE, TRI_errno_string(TRI_ERROR_QUERY_BIND_PARAMETER_TYPE), (yyvsp[0].strval).value, yylloc.first_line, yylloc.first_column);
@@ -4577,43 +4593,43 @@ yyreduce:
 
       (yyval.node) = parser->ast()->createNodeParameterDatasource((yyvsp[0].strval).value, (yyvsp[0].strval).length);
     }
-#line 4581 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 4597 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 226:
-#line 1929 "Aql/grammar.y" /* yacc.c:1646  */
+#line 1937 "Aql/grammar.y" /* yacc.c:1652  */
     {
       (yyval.node) = parser->ast()->createNodeParameter((yyvsp[0].strval).value, (yyvsp[0].strval).length);
     }
-#line 4589 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 4605 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 227:
-#line 1935 "Aql/grammar.y" /* yacc.c:1646  */
+#line 1943 "Aql/grammar.y" /* yacc.c:1652  */
     {
       (yyval.strval) = (yyvsp[0].strval);
     }
-#line 4597 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 4613 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 228:
-#line 1938 "Aql/grammar.y" /* yacc.c:1646  */
+#line 1946 "Aql/grammar.y" /* yacc.c:1652  */
     {
       (yyval.strval) = (yyvsp[0].strval);
     }
-#line 4605 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 4621 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
   case 229:
-#line 1943 "Aql/grammar.y" /* yacc.c:1646  */
+#line 1951 "Aql/grammar.y" /* yacc.c:1652  */
     {
       (yyval.strval) = (yyvsp[0].strval);
     }
-#line 4613 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 4629 "Aql/grammar.cpp" /* yacc.c:1652  */
     break;
 
 
-#line 4617 "Aql/grammar.cpp" /* yacc.c:1646  */
+#line 4633 "Aql/grammar.cpp" /* yacc.c:1652  */
       default: break;
     }
   /* User semantic actions sometimes alter yychar, and that requires
@@ -4639,14 +4655,13 @@ yyreduce:
   /* Now 'shift' the result of the reduction.  Determine what state
      that goes to, based on the state we popped back to and the rule
      number reduced by.  */
-
-  yyn = yyr1[yyn];
-
-  yystate = yypgoto[yyn - YYNTOKENS] + *yyssp;
-  if (0 <= yystate && yystate <= YYLAST && yycheck[yystate] == *yyssp)
-    yystate = yytable[yystate];
-  else
-    yystate = yydefgoto[yyn - YYNTOKENS];
+  {
+    const int yylhs = yyr1[yyn] - YYNTOKENS;
+    const int yyi = yypgoto[yylhs] + *yyssp;
+    yystate = (0 <= yyi && yyi <= YYLAST && yycheck[yyi] == *yyssp
+               ? yytable[yyi]
+               : yydefgoto[yylhs]);
+  }
 
   goto yynewstate;
 
@@ -4729,14 +4744,11 @@ yyerrlab:
 | yyerrorlab -- error raised explicitly by YYERROR.  |
 `---------------------------------------------------*/
 yyerrorlab:
+  /* Pacify compilers when the user code never invokes YYERROR and the
+     label yyerrorlab therefore never appears in user code.  */
+  if (0)
+    YYERROR;
 
-  /* Pacify compilers like GCC when the user code never invokes
-     YYERROR and the label yyerrorlab therefore never appears in user
-     code.  */
-  if (/*CONSTCOND*/ 0)
-     goto yyerrorlab;
-
-  yyerror_range[1] = yylsp[1-yylen];
   /* Do not reclaim the symbols of the rule whose action triggered
      this YYERROR.  */
   YYPOPSTACK (yylen);
@@ -4802,6 +4814,7 @@ yyacceptlab:
   yyresult = 0;
   goto yyreturn;
 
+
 /*-----------------------------------.
 | yyabortlab -- YYABORT comes here.  |
 `-----------------------------------*/
@@ -4809,6 +4822,7 @@ yyabortlab:
   yyresult = 1;
   goto yyreturn;
 
+
 #if !defined yyoverflow || YYERROR_VERBOSE
 /*-------------------------------------------------.
 | yyexhaustedlab -- memory exhaustion comes here.  |
@@ -4819,6 +4833,10 @@ yyexhaustedlab:
   /* Fall through.  */
 #endif
 
+
+/*-----------------------------------------------------.
+| yyreturn -- parsing is finished, return the result.  |
+`-----------------------------------------------------*/
 yyreturn:
   if (yychar != YYEMPTY)
     {
diff --git a/arangod/Aql/grammar.h b/arangod/Aql/grammar.h
index 69f5372e46..aaecbda37e 100644
--- a/arangod/Aql/grammar.h
+++ b/arangod/Aql/grammar.h
@@ -1,8 +1,9 @@
-/* A Bison parser, made by GNU Bison 3.0.4.  */
+/* A Bison parser, made by GNU Bison 3.3.2.  */
 
 /* Bison interface for Yacc-like parsers in C
 
-   Copyright (C) 1984, 1989-1990, 2000-2015 Free Software Foundation, Inc.
+   Copyright (C) 1984, 1989-1990, 2000-2015, 2018-2019 Free Software Foundation,
+   Inc.
 
    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
@@ -30,6 +31,9 @@
    This special exception was added by the Free Software Foundation in
    version 2.2 of Bison.  */
 
+/* Undocumented macros, especially those whose name start with YY_,
+   are private implementation details.  Do not rely on them.  */
+
 #ifndef YY_AQL_AQL_GRAMMAR_HPP_INCLUDED
 # define YY_AQL_AQL_GRAMMAR_HPP_INCLUDED
 /* Debug traces.  */
@@ -125,7 +129,7 @@ extern int Aqldebug;
 
 union YYSTYPE
 {
-#line 34 "Aql/grammar.y" /* yacc.c:1909  */
+#line 34 "Aql/grammar.y" /* yacc.c:1921  */
 
   arangodb::aql::AstNode*  node;
   struct {
@@ -135,7 +139,7 @@ union YYSTYPE
   bool                     boolval;
   int64_t                  intval;
 
-#line 139 "Aql/grammar.hpp" /* yacc.c:1909  */
+#line 143 "Aql/grammar.hpp" /* yacc.c:1921  */
 };
 
 typedef union YYSTYPE YYSTYPE;
diff --git a/arangod/Aql/grammar.hpp b/arangod/Aql/grammar.hpp
index 69f5372e46..aaecbda37e 100644
--- a/arangod/Aql/grammar.hpp
+++ b/arangod/Aql/grammar.hpp
@@ -1,8 +1,9 @@
-/* A Bison parser, made by GNU Bison 3.0.4.  */
+/* A Bison parser, made by GNU Bison 3.3.2.  */
 
 /* Bison interface for Yacc-like parsers in C
 
-   Copyright (C) 1984, 1989-1990, 2000-2015 Free Software Foundation, Inc.
+   Copyright (C) 1984, 1989-1990, 2000-2015, 2018-2019 Free Software Foundation,
+   Inc.
 
    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
@@ -30,6 +31,9 @@
    This special exception was added by the Free Software Foundation in
    version 2.2 of Bison.  */
 
+/* Undocumented macros, especially those whose name start with YY_,
+   are private implementation details.  Do not rely on them.  */
+
 #ifndef YY_AQL_AQL_GRAMMAR_HPP_INCLUDED
 # define YY_AQL_AQL_GRAMMAR_HPP_INCLUDED
 /* Debug traces.  */
@@ -125,7 +129,7 @@ extern int Aqldebug;
 
 union YYSTYPE
 {
-#line 34 "Aql/grammar.y" /* yacc.c:1909  */
+#line 34 "Aql/grammar.y" /* yacc.c:1921  */
 
   arangodb::aql::AstNode*  node;
   struct {
@@ -135,7 +139,7 @@ union YYSTYPE
   bool                     boolval;
   int64_t                  intval;
 
-#line 139 "Aql/grammar.hpp" /* yacc.c:1909  */
+#line 143 "Aql/grammar.hpp" /* yacc.c:1921  */
 };
 
 typedef union YYSTYPE YYSTYPE;
diff --git a/arangod/Aql/grammar.y b/arangod/Aql/grammar.y
index 57e4f80001..80baa9dabf 100644
--- a/arangod/Aql/grammar.y
+++ b/arangod/Aql/grammar.y
@@ -566,7 +566,6 @@ prune_and_options:
       node->addMember($2);
       // Options
       node->addMember($4);
-
     }
   ;
 
@@ -687,6 +686,15 @@ for_statement:
     } prune_and_options {
       auto graphInfoNode = static_cast<AstNode*>(parser->popStack());
       auto variablesNode = static_cast<AstNode*>(parser->popStack());
+
+      auto prune = graphInfoNode->getMember(3);
+      if (prune != nullptr) {
+        Ast::traverseReadOnly(prune, [&](AstNode const* node) {
+          if (node->type == NODE_TYPE_REFERENCE && node->hasFlag(AstNodeFlagType::FLAG_SUBQUERY_REFERENCE)) {
+            parser->registerParseError(TRI_ERROR_QUERY_PARSE, "prune condition must not use a subquery", yylloc.first_line, yylloc.first_column);
+          }
+        });
+      }
       auto node = parser->ast()->createNodeTraversal(variablesNode, graphInfoNode);
       parser->ast()->addOperation(node);
     }
@@ -1416,7 +1424,7 @@ expression_or_query:
       auto subQuery = parser->ast()->createNodeLet(variableName.c_str(), variableName.size(), node, false);
       parser->ast()->addOperation(subQuery);
 
-      $$ = parser->ast()->createNodeReference(variableName);
+      $$ = parser->ast()->createNodeSubqueryReference(variableName);
     }
   ;
 
diff --git a/tests/js/server/aql/aql-graph-traverser.js b/tests/js/server/aql/aql-graph-traverser.js
index d6db91205b..c9e51be666 100644
--- a/tests/js/server/aql/aql-graph-traverser.js
+++ b/tests/js/server/aql/aql-graph-traverser.js
@@ -2021,6 +2021,20 @@ function complexFilteringSuite() {
 
     tearDownAll: cleanup,
 
+    testPruneWithSubquery: function () {
+      let query = `FOR v,e,p IN 1..100 OUTBOUND @start @ecol PRUNE 2 <= LENGTH(FOR w IN p.vertices FILTER w._id == v._id RETURN 1) RETURN p`;
+      try {
+        let bindVars = {
+          '@eCol': en,
+          'start': vertex.Tri1
+        };
+        db._query(query, bindVars);
+        fail();
+      } catch (err) {
+        assertEqual(err.errorNum, errors.ERROR_QUERY_PARSE.code);
+      }
+    },
+
     testVertexEarlyPruneHighDepth: function () {
       var query = `WITH ${vn}
       FOR v, e, p IN 100 OUTBOUND @start @@eCol