Fallback to unsupported browser type instead of returning null

Source/bindings/dart/DartDOMWrapper.cpp

 // Copyright 2011, Google Inc.
 // 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
@@ skipping 56 matching lines @@
         if (Dart_IsError(type)) {
             DartUtilities::reportProblem(domData->scriptExecutionContext(), type);
             break;
         }
 
         if (Dart_IsNull(type)) {
             searchid = DartWebkitClassInfo[searchid].base_class_id;
         }
     }
     if ((searchid <= 0) || Dart_IsError(type) || !Dart_IsType(type) || Dart_IsNull(type)) {
-        DartUtilities::reportProblem(domData->scriptExecutionContext(), type);
-        return Dart_Null();
+        char message[256];
+        strcpy(message, "Unsupported native browser type: ");
+        strncat(message, DartWebkitClassInfo[cid].jsName, 255 - strlen(message));

[siva, 2014/08/26 19:31:14]

Why not use
snprint(message, 256, "Unsupported native browser type: %s",
DartWebkitClassInfo[cid].jsName);


Also this new error is overriding the original error that was produced by
'getType' why not do this only under
if (!Dart_IsError(type)) {
  ....
  ....
}
type = Dart_GetType(...);

[vsm, 2014/08/27 07:50:29]

Done.

+        Dart_Handle error = Dart_NewApiError(message);
+        DartUtilities::reportProblem(domData->scriptExecutionContext(), error);
+        type = Dart_GetType(htmlLibrary, Dart_NewStringFromCString("_UnsupportedBrowserObject"), 0, 0);

[siva, 2014/08/26 19:31:14]

I hope this is just a temporary solution, when we start generating
code using the actual chrome IDL instead of the way things are being
done now this should never happen right. Any error here would be more
an InternalError.

[vsm, 2014/08/27 08:05:10]

As long as we continue to push the types to user code, we do need something
defensive here.  We cannot assume we'll get a type or a valid type.

Should we also verify that this type has (at least) two native fields?  What
happens if we call Dart_AllocateWithNativeFields on some arbitrary type?

On 2014/08/26 19:31:14, siva wrote:

     }
 
     persistentType = Dart_NewPersistentHandle(type);
     (*table)[cid] = persistentType;
 
     return persistentType;
 }
 
 Dart_Handle DartDOMWrapper::exceptionCodeToDartException(ExceptionCode exceptionCode, const String& message, DartDOMData* domData)
 {
@@ skipping 17 matching lines @@
 
 Dart_Handle DartDOMWrapper::exceptionCodeToDartException(DartExceptionState& exceptionState)
 {
     DartDOMData* domData = DartDOMData::current();
     DartApiScope dartApiScope;
 
     return exceptionCodeToDartException(exceptionState.code(), exceptionState.processedMessage(), domData);
 }
 
 }