SDL 1.2 doube free/pointer zeroing missing


this is about a crash/debug breakage for the current SDL 1.2
source tree (today’s svn checkout, same problem in 1.2.13 and
before as far as relevant).
In some places memory is free()d but the associated pointer
is not zeroed, leading to for example double free()s.

For me this happened because SDL_StopEventThread() was executed
twice (during restart of the subsystems), once for the close
down in SDL_VideoQuit() and once at the startup, right at the
beginning of SDL_StartEventLoop(). Thus the code
(see SDL_events.c) was called twice and executed the
twice as well, leading to a crash (msvc 64bit for which it was

I’ve tried to check all other occurrences of SDL_free and similar
code in msvc, see the attached patch (udiff against revision 4082).
Non-windows only codepaths have neither been checked nor touched.

Comments/ideas welcome.

Attached patch: NULLifies some pointers after they
have been free()d.
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this is about a crash/debug breakage for the current SDL 1.2

Thanks! Your patch has been applied to subversion.

See ya!
-Sam Lantinga, Lead Software Engineer, Blizzard Entertainment