Doomsday Engine

In Stack_Pop the program tries to read in non-allocated space (see valgrind output below) - apparently, because the stack pointer is first decremented, and then it is read before that pointer.

Attached patch fixes the problem

Invalid read of size 8
13714    at 0x4988A3: Stack_Pop (m_stack.c:125)
13714    by 0x4A50E1: R_InitFlats (r_data.c:1510)
13714    by 0x4830A4: DD_StartupWorker (dd_main.c:593)
13714    by 0x4E39B36: SDL_RunThread (SDL_thread.c:202)
13714    by 0x4E706C8: RunThread (SDL_systhread.c:47)
13714    by 0x5094026: start_thread (pthread_create.c:297)
13714    by 0x7245CBC: clone (in /lib64/libc-2.8.so)
13714  Address 0xc9cc1e8 is 8 bytes before a block of size 16 alloc'd
13714    at 0x4C24E21: realloc (vg_replace_malloc.c:429)
13714    by 0x4988DE: Stack_Push (m_stack.c:102)
13714    by 0x4A4EB9: R_InitFlats (r_data.c:1503)
13714    by 0x4830A4: DD_StartupWorker (dd_main.c:593)
13714    by 0x4E39B36: SDL_RunThread (SDL_thread.c:202)
13714    by 0x4E706C8: RunThread (SDL_systhread.c:47)
13714    by 0x5094026: start_thread (pthread_create.c:297)
13714    by 0x7245CBC: clone (in /lib64/libc-2.8.so)

PS: Shouldn't the "if (!s)" respective now "if (s)" be an "assert(s)"?

Labels: Data