[rmodels] Loading various models causes MSVC Heapcheck to fail on unload

[HarryDC]

Please, before submitting a new issue verify and check:

• I tested it on latest raylib version from master branch
• I checked there is no similar issue already reported
• I checked the documentation on the wiki
• My code has no errors or misuse of raylib

Issue description

Using Microsoft Visual Studio and a debug build, when i load various models from the Kenney Hex set in both .obj and .glb format, runtime issues a warning about a Heap Corruption at the UnloadModel() call, the same models work fine using v5.0. This even happens when just LoadModel()/UnloadModel() is used without drawing.

After using git bisect from the current main as of today back to v5.0 the offending commit was labeled as 86ead96 (Optional GPU Skinning)

Environment

Windows 11, MSVC

Issue Screenshot

Code Example

...
model = LoadModel("resources/obj/dirt.obj");
UnloadModel(model);
...

[HarryDC]

dirt.zip

This is the model i used to check, the issue is most likely a MAX_MESH_VERTEX_BUFFERS definition in config.h line 231 that is 7, whereas the value needs to be 9 as defined in line 123 in rmodels.c

[stevegwh]

Can confirm this seems to occur on macOS with clang, too. I checked out the "Optional GPU Skinning" (86ead96) commit today and encountered the same error with "MAX_MESH_VERTEX_BUFFERS" likely being the culprit. Changing "MAX_MESH_VERTEX_BUFFERS" to "9" in config.h as suggested stopped the error.

[raysan5]

@stevegwh Thanks for finding the issue, it should be fixed now.