message: Restore exception in translateShader
  This changelist restores an exception that was removed from ShaderTranslator::translateShader, allowing the caller to tell whether a translation operation successfully modified the document.
diff: @@ -155,7 +155,7 @@ void ShaderTranslator::translateShader(NodePtr shader, const string& destCategor
  const string& sourceCategory = shader->getCategory();
  if (sourceCategory == destCategory)
  {
  - return;
  + throw Exception("The source shader \"" + shader->getNamePath() + "\" category is already \"" + destCategory + "\"");
  }
  DocumentPtr doc = shader->getDocument();
  