Index: dart/sdk/lib/_internal/compiler/implementation/lib/core_patch.dart |
diff --git a/dart/sdk/lib/_internal/compiler/implementation/lib/core_patch.dart b/dart/sdk/lib/_internal/compiler/implementation/lib/core_patch.dart |
index 934044a9a490278e2596090b860156a4d97f6053..519cf6597926af90bd3f00803d0ed71a565d4c2f 100644 |
--- a/dart/sdk/lib/_internal/compiler/implementation/lib/core_patch.dart |
+++ b/dart/sdk/lib/_internal/compiler/implementation/lib/core_patch.dart |
@@ -15,6 +15,7 @@ import "dart:_collection-dev" as _symbol_dev; |
String _symbolToString(Symbol symbol) => _symbol_dev.Symbol.getName(symbol); |
_symbolMapToStringMap(Map<Symbol, dynamic> map) { |
+ if (map == null) return null; |
var result = new Map<String, dynamic>(); |
map.forEach((Symbol key, value) { |
result[_symbolToString(key)] = value; |