Make iterator [*] internal variables need no register.

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);
+      }
     }
   };
 

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);

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
 ////////////////////////////////////////////////////////////////////////////////

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);