Trying to write into an image document (e.g. <iframe src="image.gif>) fails with an assertion in debug builds, and is just ignored in release builds.
It seems that we shouldn't subclass HTMLDocument, as all HTML documents need to support writing HTML content in them. This affects LexisNexis (requires an account to reproduce).
Created attachment 29798 [details]
test case (will assert)
This no longer fails with an assertion as of r51997, but it doesn't work either.
Seems document.write should just be ignored for image documents, like how it is for XML.
Is this what HTML5 now says? My understanding was that document.write() is supposed to behave exactly the same as it does for any HTML documents.
HTML5 throws an exception in XML docs:
But doesn't talk about image documents. Perhaps those need to have the generic write handling.