stb_ds: Fix arrfree when custom allocators are used.

[travisdoor]

Originally STBDS_FREE macro was used directly in arrfree definition,
this leads to invalid replacement in case custom realloc and free
are specified and arrfree is not used in "implementation" unit.

[nothings]

I don't see any harm in the change, but I don't understand the purpose, as arrfreef is not meant to be replaceable. What is the failure mode?

[travisdoor]

Maybe I used it wrong, my configuration looks like this:

common.c

#define STB_DS_IMPLEMENTATION
#define STBDS_REALLOC(context, ptr, size) bl_realloc(ptr, size)
#define STBDS_FREE(context, ptr) bl_free(ptr)
#include "stb_ds.h"

Now when I use arrfree in common.c file, everything is OK, the original free is replaced with bl_free, however, in other files only including stb_ds.h without any additional defines, I get default free instead of bl_free. So i.e. an array allocated from common.c and freed from a different file causes failure (bl_realloc vs default free).
My small change is just to replace STBDS_FREE in arrfree macro with a function call (having correct free in its implementation).

[nothings]

oh, yes. this was fixed before, but i guess it got lost? https://github.com/nothings/stb/pull/1144/files

[travisdoor]

hmm seems to be lost, or not being present in master

stb/stb_ds.h

Line 551 in af1a5bc

#define stbds_arrfree(a) ((void) ((a) ? STBDS_FREE(NULL,stbds_header(a)) : (void)0), (a)=NULL)

[nothings]

yep, it's clear from the diff for your PR (in the "files changed" tab) that it's missing now

[aschuhardt]

Can this be merged?

[nothings]

yes, it will be, sorry, i don't update very often since the pandemic started