1329934 - Need to call nsDocument::EnsureOnloadBlocker in nsDocument::SetScriptGlobalObject when mScriptGlobalObject changes from null to non-null

Status: RESOLVED DUPLICATE of bug 1329403

(Core :: DOM: Core & HTML, defect)

Description

[JW Wang [:jwwang] [:jw_wang]]

http://searchfox.org/mozilla-central/rev/8144fcc62054e278fe5db9666815cc13188c96fa/dom/base/nsDocument.cpp#8551
BlockOnload() might be called before mScriptGlobalObject is set.

Should we call EnsureOnloadBlocker() when mScriptGlobalObject is set and mOnloadBlockCount > 0 to add the onload blocker?

Comment 1

[Olli Pettay [:smaug][[e-mail]]]

Oh, hmm, yes maybe. Perhaps nsDocument::SetScriptGlobalObject should call  EnsureOnloadBlocker();
In practice...I wonder if there are cases when BlockOnload() isn't then called later.

Comment 2

[JW Wang [:jwwang] [:jw_wang]]

HTMLMediaElement calls BlockOnload() before loading resource, and calls UnblockOnload() after loading the first frame. So it is possible that BlockOnload() is called only once before mScriptGlobalObject is set.

This issue is particularly obvious in VideoDocument and is also what we tried to fix in bug 608634 comment 632 ~ bug 608634 comment 638.