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Bug 1627 - signal SIGSEGV SDL_UpperBlit ()
Summary: signal SIGSEGV SDL_UpperBlit ()
Status: RESOLVED INVALID
Alias: None
Product: SDL
Classification: Unclassified
Component: *don't know* (show other bugs)
Version: 1.2.14
Hardware: x86 Windows 7
: P2 normal
Assignee: Ryan C. Gordon
QA Contact: Sam Lantinga
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2012-10-23 15:21 UTC by Trent
Modified: 2014-07-08 04:43 UTC (History)
1 user (show)

See Also:

Attachments
source code (285.50 KB, application/x-tar)
2012-10-23 15:21 UTC, Trent 		Details
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Description Trent 2012-10-23 15:21:52 UTC 
Created attachment 977 [details]
source code

This bug appear with a SDL_Surface **x; and SDL_BlitSurface x[i] on a large surface (saving a map).
Pseudo code :
SDL_Surface *srf,*x[2800];
for(i=0;i<2800;i++){
    x[i]=SDL_LoadBMP("bk.bmp");
    SDL_BlitSurface(x[i],NULL,srf,&pos);
}
SDL_SaveBMP(srf,"0.bmp");

Bug does not appear using a unique SDL_Surface *x;

SDL_Surface *srf,*x;
x=SDL_LoadBMP("bk.bmp");
for(i=0;i<2800;i++){
    SDL_BlitSurface(x,NULL,srf,&pos);
}
SDL_SaveBMP(srf,"0.bmp");

--
SDL.dll version 1.2.14
Program received signal SIGSEGV, Segmentation fault.
0x681247d8 in SDL_UpperBlit ()
   from C:\Users\Trent\test2\SDL.dll
(gdb) bt
#0  0x681247d8 in SDL_UpperBlit ()
   from C:\Users\Trent\test2\SDL.dll
#1  0x00401432 in SDL_main (argc=1, argv=0x542da0) at _debug.c:18
#2  0x004024c9 in console_main (argc=1, argv=0x542da0)
    at ./src/main/win32/SDL_win32_main.c:315
#3  0x0040258b in WinMain@16 (hInst=0x400000, hPrev=0x0,
    szCmdLine=0x723bea "", sw=10) at ./src/main/win32/SDL_win32_main.c:398
#4  0x00401bd6 in main ()
Comment 1 Sylvain 2014-06-29 09:03:44 UTC 
I have checked this one.

It can be closed as the test case is bugged.

the img[] array is access out of bounds. (2704). Hence the SIGSEV.
Making img[] as 2800 solves the issue and the test case works : the large surface is correctly created.
Comment 2 Sam Lantinga 2014-07-08 04:43:34 UTC 
Thanks for checking this, Sylvain!