From e9c280368aaa237c09c8f8651640a510ef9de478 Mon Sep 17 00:00:00 2001
From: Jeong YunWon <jeong@youknowone.org>
Date: Fri, 30 Aug 2019 01:53:54 +0900
Subject: [PATCH] Fix scan_expression not to mark sequence as Load

---
 compiler/src/symboltable.rs      |  2 +-
 tests/snippets/comprehensions.py | 14 ++++++++++++++
 2 files changed, 15 insertions(+), 1 deletion(-)

diff --git a/compiler/src/symboltable.rs b/compiler/src/symboltable.rs
index 3c70d4fc2..df6c6d52e 100644
--- a/compiler/src/symboltable.rs
+++ b/compiler/src/symboltable.rs
@@ -585,7 +585,7 @@ impl SymbolTableBuilder {
             }
             Bytes { .. } => {}
             Tuple { elements } | Set { elements } | List { elements } | Slice { elements } => {
-                self.scan_expressions(elements, &ExpressionContext::Load)?;
+                self.scan_expressions(elements, context)?;
             }
             Comprehension { kind, generators } => {
                 match **kind {
diff --git a/tests/snippets/comprehensions.py b/tests/snippets/comprehensions.py
index 132f3cdcb..c87f3b168 100644
--- a/tests/snippets/comprehensions.py
+++ b/tests/snippets/comprehensions.py
@@ -27,3 +27,17 @@ z = [(9,), (10,)]
 w = [x for x, in z]
 assert w == [9, 10]
 
+# generator targets shouldn't affect scopes out of comprehensions
+[a for a in range(5)]
+assert 'a' not in locals()
+assert 'a' not in globals()
+
+[b for a, b in [(1, 1), (2, 2)]]
+assert 'b' not in locals()
+assert 'b' not in globals()
+
+{b: c for b, c in {1: 2}.items()}
+assert 'b' not in locals()
+assert 'c' not in locals()
+assert 'b' not in globals()
+assert 'c' not in globals()