Introduce legacy const slots in correct context.

R=rossberg@chromium.org
BUG=chromium:410030
LOG=Y

Review URL: https://codereview.chromium.org/756293004

Cr-Commit-Position: refs/heads/master@{#25519}

src/runtime/runtime-scopes.cc

@@ -314,9 +314,11 @@ RUNTIME_FUNCTION(Runtime_InitializeLegacyConstLookupSlot) {
 
   // The declared const was configurable, and may have been deleted in the
   // meanwhile. If so, re-introduce the variable in the context extension.
-  DCHECK(context_arg->has_extension());
   if (attributes == ABSENT) {
-    holder = handle(context_arg->extension(), isolate);
+    Handle<Context> declaration_context(context_arg->declaration_context());
+    DCHECK(declaration_context->has_extension());
+    holder = handle(declaration_context->extension(), isolate);
+    CHECK(holder->IsJSObject());
   } else {
     // For JSContextExtensionObjects, the initializer can be run multiple times
     // if in a for loop: for (var i = 0; i < 2; i++) { const x = i; }. Only the

test/mjsunit/regress/regress-410030.js

+// Copyright 2014 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+try {
+  throw 0;
+} catch(e) {
+  assertSame(3, eval("delete x; const x=3; x"));
+}
+
+
+try {
+  throw 0;
+} catch(e) {
+  assertSame(3, (1,eval)("delete x1; const x1=3; x1"));
+}
+
+
+try {
+  throw 0;
+} catch(e) {
+  with({}) {
+    assertSame(3, eval("delete x2; const x2=3; x2"));
+  }
+}
+
+
+(function f() {
+  try {
+    throw 0;
+  } catch(e) {
+    assertSame(3, eval("delete x; const x=3; x"));
+  }
+}());
+
+
+(function f() {
+  try {
+    throw 0;
+  } catch(e) {
+    assertSame(3, (1,eval)("delete x4; const x4=3; x4"));
+  }
+}());