From 596b015e990cc86883d25956c84a4ba4171cd1da Mon Sep 17 00:00:00 2001
From: Teon Banek <theongugl@gmail.com>
Date: Wed, 12 Apr 2017 16:08:01 +0200
Subject: [PATCH] Correctly check variables inside property maps

Reviewers: florijan, mislav.bradac

Reviewed By: mislav.bradac

Subscribers: pullbot

Differential Revision: https://phabricator.memgraph.io/D271
---
 .../frontend/semantic/symbol_generator.cpp    | 13 ++++--------
 tests/unit/query_semantic.cpp                 | 21 +++++++++++++++++++
 2 files changed, 25 insertions(+), 9 deletions(-)

diff --git a/src/query/frontend/semantic/symbol_generator.cpp b/src/query/frontend/semantic/symbol_generator.cpp
index 1ad6bc9e1..a9898dcfc 100644
--- a/src/query/frontend/semantic/symbol_generator.cpp
+++ b/src/query/frontend/semantic/symbol_generator.cpp
@@ -73,12 +73,10 @@ void SymbolGenerator::PostVisit(With &with) {
 
 void SymbolGenerator::Visit(Identifier &ident) {
   Symbol symbol;
-  if (scope_.in_pattern) {
+  if (scope_.in_pattern && !scope_.in_property_map) {
     // Patterns can bind new symbols or reference already bound. But there
     // are the following special cases:
-    //  1) Expressions in property maps `{prop_name: expr}` can only reference
-    //     bound variables.
-    //  2) Patterns used to create nodes and edges cannot redeclare already
+    //  1) Patterns used to create nodes and edges cannot redeclare already
     //     established bindings. Declaration only happens in single node
     //     patterns and in edge patterns. OpenCypher example,
     //     `MATCH (n) CREATE (n)` should throw an error that `n` is already
@@ -87,12 +85,9 @@ void SymbolGenerator::Visit(Identifier &ident) {
     //     Additionally, we will support edge referencing in pattern:
     //     `MATCH (n) - [r] -> (n) - [r] -> (n) RETURN r`, which would
     //     usually raise redeclaration of `r`.
-    if (scope_.in_property_map && !HasSymbol(ident.name_)) {
-      // Case 1)
-      throw UnboundVariableError(ident.name_);
-    } else if ((scope_.in_create_node || scope_.in_create_edge) &&
+    if ((scope_.in_create_node || scope_.in_create_edge) &&
                HasSymbol(ident.name_)) {
-      // Case 2)
+      // Case 1)
       throw RedeclareVariableError(ident.name_);
     }
     auto type = Symbol::Type::Vertex;
diff --git a/tests/unit/query_semantic.cpp b/tests/unit/query_semantic.cpp
index d26f728c7..287f5bfd0 100644
--- a/tests/unit/query_semantic.cpp
+++ b/tests/unit/query_semantic.cpp
@@ -447,4 +447,25 @@ TEST(TestSymbolGenerator, NestedAggregation) {
   EXPECT_THROW(query->Accept(symbol_generator), SemanticException);
 }
 
+TEST(TestSymbolGenerator, MatchPropCreateNodeProp) {
+  // Test MATCH (n) CREATE (m {prop: n.prop})
+  Dbms dbms;
+  auto dba = dbms.active();
+  auto prop = dba->property("prop");
+  AstTreeStorage storage;
+  auto node_n = NODE("n");
+  auto node_m = NODE("m");
+  auto n_prop = PROPERTY_LOOKUP("n", prop);
+  node_m->properties_[prop] = n_prop;
+  auto query = QUERY(MATCH(PATTERN(node_n)), CREATE(PATTERN(node_m)));
+  SymbolTable symbol_table;
+  SymbolGenerator symbol_generator(symbol_table);
+  query->Accept(symbol_generator);
+  EXPECT_EQ(symbol_table.max_position(), 2);
+  auto n = symbol_table.at(*node_n->identifier_);
+  EXPECT_EQ(n, symbol_table.at(*n_prop->expression_));
+  auto m = symbol_table.at(*node_m->identifier_);
+  EXPECT_NE(n, m);
+}
+
 }