Merge 92298 - Crash in DocumentWriter::endIfNotLoadingMainResource

Merge 92298 - Crash in DocumentWriter::endIfNotLoadingMainResource
https://bugs.webkit.org/show_bug.cgi?id=65581

Reviewed by Nate Chapin.

Source/WebCore:

This function is poorly designed because isLoadingMainResource is a
poor proxy for determing whether to flush/finish the parser.  Really,
we should change how loads complete to match the model in HTML5, but
that's pretty tricky.  In the meantime, this null check fixes the
crash.

I'm sure there's another bug on file about this crash, but we've never
been able to reproduce it.  Thanks to Berend-Jan Wever for the test
case!

Test: fast/loader/reload-zero-byte-plugin.html

* loader/DocumentWriter.cpp:
(WebCore::DocumentWriter::endIfNotLoadingMainResource):

LayoutTests:

* fast/loader/reload-zero-byte-plugin-expected.txt: Added.
* fast/loader/reload-zero-byte-plugin.html: Added.


TBR=abarth@webkit.org
Committed: http://src.chromium.org/viewvc/chrome?view=rev&revision=93569