From 8290bc64fb8bd769713f32ca2ab65b0d29d52a20 Mon Sep 17 00:00:00 2001
From: Max Neunhoeffer <max@arangodb.com>
Date: Mon, 11 Aug 2014 13:47:23 +0200
Subject: [PATCH] Make iterator [*] internal variables need no register.

---
 arangod/Aql/Ast.cpp          |  6 ++++--
 arangod/Aql/ExecutionBlock.h |  3 +++
 arangod/Aql/Variable.h       | 13 ++++++++++++-
 arangod/Aql/grammar.y        |  2 +-
 4 files changed, 20 insertions(+), 4 deletions(-)

diff --git a/arangod/Aql/Ast.cpp b/arangod/Aql/Ast.cpp
index 76ad2b693c..0999a264ac 100644
--- a/arangod/Aql/Ast.cpp
+++ b/arangod/Aql/Ast.cpp
@@ -886,8 +886,10 @@ std::unordered_set<Variable*> Ast::getReferencedVariables (AstNode const* node)
         THROW_ARANGO_EXCEPTION(TRI_ERROR_OUT_OF_MEMORY);
       }
 
-      auto result = static_cast<std::unordered_set<Variable*>*>(data);
-      result->insert(variable);
+      if (variable->needsRegister()) {
+        auto result = static_cast<std::unordered_set<Variable*>*>(data);
+        result->insert(variable);
+      }
     }
   };
 
diff --git a/arangod/Aql/ExecutionBlock.h b/arangod/Aql/ExecutionBlock.h
index 553d9b1783..93aa20f282 100644
--- a/arangod/Aql/ExecutionBlock.h
+++ b/arangod/Aql/ExecutionBlock.h
@@ -1426,6 +1426,9 @@ namespace triagens {
           auto en = static_cast<CalculationNode const*>(getPlanNode());
 
           std::unordered_set<Variable*> inVars = _expression->variables();
+          for (auto it : inVars) {
+            std::cout << it->name << ":" << it->id << std::endl;
+          }
 
           for (auto it = inVars.begin(); it != inVars.end(); ++it) {            
             _inVars.push_back(*it);
diff --git a/arangod/Aql/Variable.h b/arangod/Aql/Variable.h
index e8135045c3..b9a8830509 100644
--- a/arangod/Aql/Variable.h
+++ b/arangod/Aql/Variable.h
@@ -109,10 +109,21 @@ namespace triagens {
 
       inline bool isUserDefined () const {
         char const c = name[0];
-        // variables starting with a number are user-defined
+        // variables starting with a number are not user-defined
         return (c < '0' || c > '9');
       }
 
+////////////////////////////////////////////////////////////////////////////////
+/// @brief whether or not the variable needs a register assigned
+////////////////////////////////////////////////////////////////////////////////
+
+      inline bool needsRegister () const {
+        char const cf = name[0];
+        char const cb = name.back();
+        // variables starting with a number are not user-defined
+        return (cf < '0' || cf > '9') || cb != '_';
+      }
+
 ////////////////////////////////////////////////////////////////////////////////
 /// @brief return a JSON representation of the variable
 ////////////////////////////////////////////////////////////////////////////////
diff --git a/arangod/Aql/grammar.y b/arangod/Aql/grammar.y
index 3b4c5ee7b1..2410c1f16d 100644
--- a/arangod/Aql/grammar.y
+++ b/arangod/Aql/grammar.y
@@ -689,7 +689,7 @@ reference:
       // expanded variable access, e.g. variable[*]
 
       // create a temporary iterator variable
-      std::string const nextName = parser->ast()->variables()->nextName();
+      std::string const nextName = parser->ast()->variables()->nextName() + "_";
       char const* iteratorName = nextName.c_str();
       auto iterator = parser->ast()->createNodeIterator(iteratorName, $1);