Created attachment 515566 [details]
###!!! ASSERTION: Default canvas font is invalid: 'res == NS_OK',
file content/canvas/src/nsCanvasRenderingContext2D.cpp, line 2885
Created attachment 515567 [details]
stack trace (mac)
This has nothing to do with moving between frames. This assert will fire any time you use a <canvas> that's inside a document with no presshell (as in this case).
I personally think the assert is bogus (and that the behavior is possibly semi-bogus too).
Bug 647480 fixes this by muting the assert if there is no pres shell.
It doesn't seem right to simply mute the assert, if the real problem is that we don't know how to deal with the font of a canvas in this situation - shouldn't we be fixing _that_ issue?
Created attachment 523905 [details] [diff] [review]
I guess we could try harder to create something, also in the
absence of a pres shell... is that what you're suggesting?
Comment on attachment 523905 [details] [diff] [review]
I merged this into the patch in bug 647480...
Seems to have been fixed by the patch in bug 647480.