crash [@ mozilla::WebGLContext::ReadPixels(int, int, int, int, unsigned int, unsigned int) ]




9 years ago
9 years ago


(Reporter: aSydiK, Unassigned)


Firefox Tracking Flags

(Not tracked)





9 years ago
User-Agent:       Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv: Gecko/20100423 Ubuntu/10.04 (lucid) Firefox/3.6.3
Build Identifier: 

Background details:  I'm trying to readPixels off an invisible (back-buffer) 3D canvas and draw it on an invisible (back-buffer) 2D canvas (red - for differentiation).  I use the said 2D canvas (red) and draw it on a rendered 2D canvas (green).

Doing this, crashes the browser.  I was getting security errors a little while back... but now it's just a crash.  The crash reports are attached in the additional info.

Reproducible: Always

Steps to Reproduce:
1. Open site attached
2. Wait a few seconds
3. Crash
Actual Results:  

Expected Results:  
Rendered a 2D canvas with a green background and a 3D canvas with a red background and moving objects drawn in the 2D one.

Crash report on Windows:
Crash report on Linux (less useful as there's no stack):
Crash on Mac, too:
Ever confirmed: true
OS: Linux → All
Hardware: x86_64 → All
That's weird, I can't reproduce this crash in either a debug or regular build (on win32)...
Takes me upwards of 30 seconds for it to happen, never happens right away.
Yeah, no go, been running for 5-10 min now...

Comment 5

9 years ago
I was able to reproduce it 4 times now on Windows... though there was a new development... it would only first crash if I brought up the error console (so I could check on the problems)... after the first crash, just bringing up the page would crash it again.  Won't include the crash reports as they look the same as the first one.
So the only thing I can think of is that the canvas element is null; can I get you to get it in a debugger (WinDbg is fine) and look at the value of mCanvasElement at the crash?  (Should be able to pull in symbols via the mozilla symbol server.)
Can someone who sees this get a full minidump?  That would probably help a lot.
I've got a browser with symbols and am trying to get this via gdb, but I can no longer reproduce this with the current page at the URL listed.  Mickael, did you update the page at the URL above?  When it crashed for me previously, I only saw 1 canvas, now I see 3.
I only ever saw 3.  Were the others perhaps doing multiple getContext() calls on the same canvas?  I can think of that causing the problem described here.

Comment 10

9 years ago
Ugh... no wonder... wrong link... sorry.

Comment 11

9 years ago
Changed to proper link.
ReadPixels has just been rewritten (landed 2 days ago). I've tried your URL today and it's not crashing Minefield. Can you retry and confirm?

Comment 13

9 years ago
Sorry for the late reply.  Just checked my page and Minefield isn't crashing... awesome!
great, thanks for confirming.
Last Resolved: 9 years ago
Resolution: --- → FIXED
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