In many cases, error messages may not get logged, because there is no frame or page to call addMessageToConsole() on, e.g.: void SVGDocumentExtensions::reportWarning(const String& message) { if (Page* page = m_doc->frame()->page()) page->chrome()->addMessageToConsole("Warning: " + message, m_doc->tokenizer() ? m_doc->tokenizer()->lineNumber() : 1, String()); } It would be good to find a way not to lose these messages.
This line is changed now: https://github.com/WebKit/WebKit/blob/0393f2f7c7a1e97a7a4c63441b50703cc11d493f/Source/WebCore/svg/SVGDocumentExtensions.cpp#L134 ap@webkit.org - is it something still need to be fixed?
I'm not sure. But if it hasn't been done in 15 years, keeping this bug open won't get it done.