In the unlikely case that the overflow check should fail,
the else clause would switch to the truncated stack message
without updating the len variable. This would contain the
return value from vsnprintf(), meaning it could point beyond
the buffer.
The subsequent code which trims NL and CR from the buffer,
would then read -- and possibly write -- out-of-bounds.
To fix this, we split the two joint conditions into separate
if-clauses, and adjust the len variable in the case where we
know the message buffer was truncated.
Move rendering of the assert message into a separate
function so we can remove the ugly loop construction.
Changes the logic such that allocation failure no longer
immediately returns SDL_ASSERTION_ABORT, instead we
fall back to the truncated message.
If an error is indicated from SDL_snprintf, then we do
abort with SDL_ASSERTION_ABORT.
Ensure that we're not trying to call SDL_small_alloc()
with a count of zero.
Transforming the code like this fixes a
-Wmaybe-uninitialized warning from GCC 12.0.1
For short messages, use a stack buffer that is
significantly smaller than SDL_MAX_LOG_MESSAGE.
The rationale for this is that we don't want to risk
blowing the stack, while at the same time we would
like to not put pressure on the memory allocator unless
absolutely necessary.
if SDL_EnumUnixAudioDevices() fails to find any devices,
set an error message on the exit path. Without this,
SDL_Init() could fail without any message available
in SDL_GetError().