[AD] electricfence testing results (2)

[Martijn Versteegh <m.versteegh@xxxxxxxxxx>]

Some extra things I foudn out just after I sent this mail.
>Hi all,
>
>I didn't have time to get the latest cvs version yet, but I did some tests
>on '38 instead.
>
>When run with the electricfence memory debugger I get a segmentation fault
>under these conditions:
>
>-running in X, 16 bit colordepth, while the program runs in 24 bit colordepth
>-linking with the shared lib (when linking statically the crash disappears)
This is not true for my own program. Ther the crash is persistent, no matter which lib
I use.

>
>when run from within gdb I get the following traceback from a program of mine:
>--------------
>Program received signal SIGSEGV, Segmentation fault.
>[Switching to Thread 1024 (LWP 11281)]
>0x805e148 in sprite_x_loop_draw_sprite () at test.cpp:513
>513     {
>Current language:  auto; currently c++
>(gdb) bt
>#0  0x805e148 in sprite_x_loop_draw_sprite () at test.cpp:513
>#1  0x85c8002b in ?? ()
>#2  0x400c6481 in _xwin_replace_vtable () from /usr/local/lib/liballd-3.9.38.so
>#3  0x4008a976 in draw_sprite () from /usr/local/lib/liballd-3.9.38.so
>#4  0x4009df94 in gfx_mode_select_ex () from /usr/local/lib/liballd-3.9.38.so
>#5  0x4009e9c5 in show_mouse () from /usr/local/lib/liballd-3.9.38.so
>#6  0x805217a in init () at test.cpp:254
>#7  0x80525c3 in _mangled_main (argc=2, argv=0xbffff57c) at test.cpp:340
>#8  0x400bb8b5 in main () from /usr/local/lib/liballd-3.9.38.so
>#9  0x40130baf in __libc_start_main () from /lib/libc.so.6
>(gdb) 


The program also crashes without electricfence when I move the mouse when
it's 'scared' (scare_mouse) so I suspect it has something to do with the mouse
drawing code. AFAIK i have a hardware mouse cursor, but allegro doesn't use it.
Maybe something gets mixed up there so that allegro thinks it uses a hardware
cursor and doesn't need to hide it and then the mouse_drawing code screws up?

Just some wild guesses as I don't know what's going on ;-(

--
Martijn Versteegh