Censor .caller if it is a strict function instead of throwing.

src/accessors.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 631 matching lines @@
   ReadOnlySetAccessor,
   0
 };
 
 
 //
 // Accessors::FunctionCaller
 //
 
 
-static MaybeObject* CheckNonStrictCallerOrThrow(
-    Isolate* isolate,
-    JSFunction* caller) {
-  DisableAssertNoAllocation enable_allocation;
-  if (!caller->shared()->is_classic_mode()) {
-    return isolate->Throw(
-        *isolate->factory()->NewTypeError("strict_caller",
-                                          HandleVector<Object>(NULL, 0)));
-  }
-  return caller;
-}
-
-
 class FrameFunctionIterator {
  public:
   FrameFunctionIterator(Isolate* isolate, const AssertNoAllocation& promise)
       : frame_iterator_(isolate),
         functions_(2),
         index_(0) {
     GetFunctions();
   }
   JSFunction* next() {
     if (functions_.length() == 0) return NULL;
@@ skipping 66 matching lines @@
   }
   if (!caller->shared()->native() && potential_caller != NULL) {
     caller = potential_caller;
   }
   // If caller is bound, return null. This is compatible with JSC, and
   // allows us to make bound functions use the strict function map
   // and its associated throwing caller and arguments.
   if (caller->shared()->bound()) {
     return isolate->heap()->null_value();
   }
-  return CheckNonStrictCallerOrThrow(isolate, caller);
+  // Censor if the caller is not a classic mode function.
+  // Change from ES5, which used to throw, see:
+  // https://bugs.ecmascript.org/show_bug.cgi?id=310
+  if (!caller->shared()->is_classic_mode()) {
+    return isolate->heap()->null_value();
+  }
+
+  return caller;
 }
 
 
 const AccessorDescriptor Accessors::FunctionCaller = {
   FunctionGetCaller,
   ReadOnlySetAccessor,
   0
 };
 
 
@@ skipping 86 matching lines @@
   info->set_data(Smi::FromInt(index));
   Handle<Object> getter = v8::FromCData(&ModuleGetExport);
   Handle<Object> setter = v8::FromCData(&ModuleSetExport);
   info->set_getter(*getter);
   if (!(attributes & ReadOnly)) info->set_setter(*setter);
   return info;
 }
 
 
 } }  // namespace v8::internal