When loading cached XUL dynamic overlays the document gets saved to the startup cache even though it had been already put in the startup cache when the overlay was originally cached.
Steps to reproduce problem:
1. Open a XUL document that uses dynamic overlays
2. Close and reopen the document
Expected result: Startup cache written once
Actual result: Startup cache written twice
###!!! ASSERTION: Existing entry in StartupCache.: 'entry == nsnull', file startupcache/StartupCache.cpp, line 298
Presumably the old fastload cache didn't do the check.
Created attachment 549356 [details] [diff] [review]
We should only set mIsFastLoad if we're actually doing a load. We already do this correctly in the two places where we trigger loads (later on in this method and also in StartDocumentLoad). So the code snippet is bogus.
Pushed changeset ed772265d2bc to mozilla-central.