From b6ecc5631f06de18b10172c84b84300e8da564c2 Mon Sep 17 00:00:00 2001
From: Mislav Bradac <mislav.bradac@memgraph.io>
Date: Tue, 20 Jun 2017 11:55:24 +0200
Subject: [PATCH] Disallow keywords as symbolic names

Reviewers: teon.banek, buda

Reviewed By: buda

Subscribers: pullbot

Differential Revision: https://phabricator.memgraph.io/D497
---
 src/query/frontend/ast/cypher_main_visitor.cpp |  9 ++++++++-
 tests/unit/cypher_main_visitor.cpp             | 17 +++++++++++++++++
 2 files changed, 25 insertions(+), 1 deletion(-)

diff --git a/src/query/frontend/ast/cypher_main_visitor.cpp b/src/query/frontend/ast/cypher_main_visitor.cpp
index b2f261ca2..a6961ecbb 100644
--- a/src/query/frontend/ast/cypher_main_visitor.cpp
+++ b/src/query/frontend/ast/cypher_main_visitor.cpp
@@ -332,7 +332,14 @@ antlrcpp::Any CypherMainVisitor::visitSymbolicName(
     }
     return name;
   }
-  return std::string(ctx->getText());
+  if (ctx->UnescapedSymbolicName() || ctx->HexLetter()) {
+    return std::string(ctx->getText());
+  }
+  // Symbolic names are case sensitive. Since StrippedQuery lowercases all
+  // keywords there is no way to differentiate between differently cased
+  // symbolic names if they are equal to a keyword.
+  throw SemanticException(
+      fmt::format("Symbolic name can't be keyword {}", ctx->getText()));
 }
 
 antlrcpp::Any CypherMainVisitor::visitPattern(
diff --git a/tests/unit/cypher_main_visitor.cpp b/tests/unit/cypher_main_visitor.cpp
index 36506c91e..57ddb9b04 100644
--- a/tests/unit/cypher_main_visitor.cpp
+++ b/tests/unit/cypher_main_visitor.cpp
@@ -143,6 +143,23 @@ TYPED_TEST(CypherMainVisitorTest, EscapedLabel) {
               ElementsAre(ast_generator.db_accessor_->label("l-$\"'ab`e``l")));
 }
 
+TYPED_TEST(CypherMainVisitorTest, KeywordLabel) {
+  ASSERT_THROW(TypeParam("RETURN n:DEletE"), SemanticException);
+}
+
+TYPED_TEST(CypherMainVisitorTest, HexLetterLabel) {
+  TypeParam ast_generator("RETURN n:a");
+  auto *query = ast_generator.query_;
+  ASSERT_EQ(query->clauses_.size(), 1U);
+  auto *return_clause = dynamic_cast<Return *>(query->clauses_[0]);
+  auto *labels_test = dynamic_cast<LabelsTest *>(
+      return_clause->body_.named_expressions[0]->expression_);
+  auto identifier = dynamic_cast<Identifier *>(labels_test->expression_);
+  EXPECT_EQ(identifier->name_, "n");
+  ASSERT_THAT(labels_test->labels_,
+              ElementsAre(ast_generator.db_accessor_->label("a")));
+}
+
 TYPED_TEST(CypherMainVisitorTest, ReturnNoDistinctNoBagSemantics) {
   TypeParam ast_generator("RETURN x");
   auto *query = ast_generator.query_;