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Bug 756 - Memory leak in DirectDraw backend
Summary: Memory leak in DirectDraw backend
Status: RESOLVED WONTFIX
Alias: None
Product: SDL
Classification: Unclassified
Component: video (show other bugs)
Version: 1.2.13
Hardware: x86 Windows (All)
: P2 normal
Assignee: Sam Lantinga
QA Contact: Sam Lantinga
URL:
Keywords: target-1.2.14
Depends on:
Blocks:
 
Reported: 2009-06-20 14:33 UTC by Steven Don
Modified: 2009-10-17 11:08 UTC (History)
1 user (show)

See Also:

Attachments
Fix for memory leak (1.16 KB, patch)
2009-06-20 14:33 UTC, Steven Don 		Details | Diff
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Description Steven Don 2009-06-20 14:33:05 UTC 
Created attachment 333 [details]
Fix for memory leak

Certain codepaths in the DirectDraw backend for SDL 1.2 SDL_malloc a buffer which is never SDL_free'd. Instead, the pointer is simply overwritten by a pointer to a DirectDraw surface when the surface is locked. That is a memory leak.

The patch attached stores the pointer for later proper release.

I also posted this to the mailing list, and was directed to submit it here.
Comment 1 Sam Lantinga 2009-06-30 22:11:39 UTC 
When does surface->pixels get allocated prior to DX5_LockHWSurface()?
Comment 2 Steven Don 2009-07-01 11:01:15 UTC 
In SDL_SetVideoMode. The reason I've left it in and don't just SDL_Free it immediately on a lock is on the off-chance that some badly behaved program grabs the pointer immediately after SDL_SetVideoMode and uses it. Freeing it immediately or not allocating it at all would break compatibility with such programs. Personally I think that should be avoided if it can be helped.
Comment 3 Ryan C. Gordon 2009-09-13 16:33:01 UTC 
Tagging this bug with "target-1.2.14" so we can try to resolve it for SDL 1.2.14.

Please note that we may choose to resolve it as WONTFIX. This tag is largely so we have a comprehensive wishlist of bugs to examine for 1.2.14 (and so we can close bugs that we'll never fix, rather than have them live forever in Bugzilla).

--ryan.
Comment 4 Sam Lantinga 2009-09-26 21:06:21 UTC 
Can you give me a test case that reproduces the memory leak?  I'd like to fully understand what's going on before I apply this patch.

Thanks!
Comment 5 Sam Lantinga 2009-10-17 11:08:40 UTC 
This is a risky change for SDL 1.2, so I'm going to hold off fixing it for now.  If you have a test case, please re-open this bug.

Thanks!