Always check global property cells for readonliness before storing.

src/ia32/stub-cache-ia32.cc

Index: src/ia32/stub-cache-ia32.cc
diff --git a/src/ia32/stub-cache-ia32.cc b/src/ia32/stub-cache-ia32.cc
index fcc06fada7fa2886125a5db80bdb1d1d5cfee12a..f70d5238f95f825f4c0cf9eaceaf6c3410386404 100644
--- a/src/ia32/stub-cache-ia32.cc
+++ b/src/ia32/stub-cache-ia32.cc
@@ -726,6 +726,29 @@ void BaseStoreStubCompiler::GenerateRestoreName(MacroAssembler* masm,
 }
 
 
+// Generate code to check that a global property cell is empty. Create
+// the property cell at compilation time if no cell exists for the
+// property.
+static void GenerateCheckPropertyCell(MacroAssembler* masm,
+                                      Handle<GlobalObject> global,
+                                      Handle<Name> name,
+                                      Register scratch,
+                                      Label* miss) {
+  Handle<JSGlobalPropertyCell> cell =
+      GlobalObject::EnsurePropertyCell(global, name);
+  ASSERT(cell->value()->IsTheHole());
+  Handle<Oddball> the_hole = masm->isolate()->factory()->the_hole_value();
+  if (Serializer::enabled()) {
+    __ mov(scratch, Immediate(cell));
+    __ cmp(FieldOperand(scratch, JSGlobalPropertyCell::kValueOffset),
+           Immediate(the_hole));
+  } else {
+    __ cmp(Operand::Cell(cell), Immediate(the_hole));
+  }
+  __ j(not_equal, miss);
+}
+
+
 // Both name_reg and receiver_reg are preserved on jumps to miss_label,
 // but may be destroyed if store is successful.
 void StubCompiler::GenerateStoreField(MacroAssembler* masm,
@@ -771,12 +794,18 @@ void StubCompiler::GenerateStoreField(MacroAssembler* masm,
     // If no property was found, and the holder (the last object in the
     // prototype chain) is in slow mode, we need to do a negative lookup on the
     // holder.
-    if (lookup->holder() == *object &&
-        !holder->HasFastProperties() &&
-        !holder->IsJSGlobalProxy() &&
-        !holder->IsJSGlobalObject()) {
-      GenerateDictionaryNegativeLookup(
-          masm, miss_restore_name, holder_reg, name, scratch1, scratch2);
+    if (lookup->holder() == *object) {
+      if (holder->IsJSGlobalObject()) {
+        GenerateCheckPropertyCell(
+            masm,
+            Handle<GlobalObject>(GlobalObject::cast(holder)),
+            name,
+            scratch1,
+            miss_restore_name);
+      } else if (!holder->HasFastProperties() && !holder->IsJSGlobalProxy()) {
+        GenerateDictionaryNegativeLookup(
+            masm, miss_restore_name, holder_reg, name, scratch1, scratch2);
+      }
     }
   }
 
@@ -864,29 +893,6 @@ void StubCompiler::GenerateStoreField(MacroAssembler* masm,
 }
 
 
-// Generate code to check that a global property cell is empty. Create
-// the property cell at compilation time if no cell exists for the
-// property.
-static void GenerateCheckPropertyCell(MacroAssembler* masm,
-                                      Handle<GlobalObject> global,
-                                      Handle<Name> name,
-                                      Register scratch,
-                                      Label* miss) {
-  Handle<JSGlobalPropertyCell> cell =
-      GlobalObject::EnsurePropertyCell(global, name);
-  ASSERT(cell->value()->IsTheHole());
-  Handle<Oddball> the_hole = masm->isolate()->factory()->the_hole_value();
-  if (Serializer::enabled()) {
-    __ mov(scratch, Immediate(cell));
-    __ cmp(FieldOperand(scratch, JSGlobalPropertyCell::kValueOffset),
-           Immediate(the_hole));
-  } else {
-    __ cmp(Operand::Cell(cell), Immediate(the_hole));
-  }
-  __ j(not_equal, miss);
-}
-
-
 // Calls GenerateCheckPropertyCell for each global object in the prototype chain
 // from object to (but not including) holder.
 static void GenerateCheckPropertyCells(MacroAssembler* masm,