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Bug 3196 - Segmentation fault when using window surface and accelerated renderer
Summary: Segmentation fault when using window surface and accelerated renderer
Status: RESOLVED FIXED
Alias: None
Product: SDL
Classification: Unclassified
Component: render (show other bugs)
Version: 2.0.2
Hardware: x86_64 Linux
: P2 normal
Assignee: Sam Lantinga
QA Contact: Sam Lantinga
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2015-12-03 18:47 UTC by Ferdinand Vesely
Modified: 2016-01-02 18:20 UTC (History)
2 users (show)

See Also:

Attachments
Test program (586 bytes, text/x-csrc)
2015-12-03 18:47 UTC, Ferdinand Vesely 		Details
GDB backtrace leading to SDL_InvalidateMap (988 bytes, text/plain)
2015-12-03 18:49 UTC, Ferdinand Vesely 		Details
GDB backtrace leading to SDL_FreePalette_REAL (1.01 KB, text/plain)
2015-12-03 18:50 UTC, Ferdinand Vesely 		Details
patch to fix a crash (445 bytes, patch)
2015-12-04 20:38 UTC, Philipp Wiesemann 		Details | Diff
View All Add an attachment (proposed patch, testcase, etc.)

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Description Ferdinand Vesely 2015-12-03 18:47:43 UTC 
Created attachment 2322 [details]
Test program

I get a segmentation fault (occasionally an invalid pointer error from free()) when accessing the window surface using SDL_GetWindowSurface and then creating a renderer using SDL_CreateRenderer with SDL_RENDERER_ACCELERATED on the same window. The segfault happens when SDL_DestroyWindow is called and the backtrace leads to SDL_InvalidateMap and sometimes to SDL_FreePalette_REAL.

I couldn't trigger the segfault it with SDL_RENDERER_SOFTWARE. Also if I remove the call to SDL_GetWindowSurface it works fine. Drawing using the accelerated renderer also works without a problem.

The test program is attached.
Comment 1 Ferdinand Vesely 2015-12-03 18:49:13 UTC 
Created attachment 2323 [details]
GDB backtrace leading to SDL_InvalidateMap
Comment 2 Ferdinand Vesely 2015-12-03 18:50:55 UTC 
Created attachment 2324 [details]
GDB backtrace leading to SDL_FreePalette_REAL
Comment 3 Philipp Wiesemann 2015-12-04 20:38:06 UTC 
Created attachment 2328 [details]
patch to fix a crash

The attached patch seems to fix a crash (but maybe only by coincidence and not fixing the actual fault).
Comment 4 Ryan C. Gordon 2015-12-29 05:53:08 UTC 
(In reply to Philipp Wiesemann from comment #3)
> Created attachment 2328 [details]
> patch to fix a crash
> 
> The attached patch seems to fix a crash (but maybe only by coincidence and
> not fixing the actual fault).

This looks like a good fix (whether it resolves this bug or not), so feel free to push that change if you want, Phillipp.

--ryan.
Comment 5 Philipp Wiesemann 2015-12-29 18:22:47 UTC 
The first patch was applied here:
https://hg.libsdl.org/SDL/rev/08d023f75d78
Comment 6 Sam Lantinga 2016-01-02 18:20:53 UTC 
Thanks!