Zebediah Figura : wined3d: Always bind to GL_ELEMENT_ARRAY_BUFFER if the bind flags include WINED3D_BIND_INDEX_BUFFER.

[Alexandre Julliard]

Module: wine
Branch: master
Commit: 33d6900b35f510d17d6d5b1dc0936e7cc7136d73
URL:    https://gitlab.winehq.org/wine/wine/-/commit/33d6900b35f510d17d6d5b1dc0936e7...

Author: Zebediah Figura <zfigura(a)codeweavers.com>
Date:   Tue Dec 13 20:42:33 2022 -0600

wined3d: Always bind to GL_ELEMENT_ARRAY_BUFFER if the bind flags include WINED3D_BIND_INDEX_BUFFER.

Wine-Bug: https://bugs.winehq.org/show_bug.cgi?id=53623

---

 dlls/wined3d/buffer.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/dlls/wined3d/buffer.c b/dlls/wined3d/buffer.c
index 2f6c52ef36f..fa24f006872 100644
--- a/dlls/wined3d/buffer.c
+++ b/dlls/wined3d/buffer.c
@@ -141,7 +141,11 @@ GLenum wined3d_buffer_gl_binding_from_bind_flags(const struct wined3d_gl_info *g
     if (!bind_flags)
         return GL_PIXEL_UNPACK_BUFFER;
 
-    if (bind_flags == WINED3D_BIND_INDEX_BUFFER)
+    /* We must always return GL_ELEMENT_ARRAY_BUFFER here;
+     * wined3d_device_gl_create_bo() checks the GL binding to see whether we
+     * can suballocate, and we cannot suballocate if this BO might be used for
+     * an index buffer. */
+    if (bind_flags & WINED3D_BIND_INDEX_BUFFER)
         return GL_ELEMENT_ARRAY_BUFFER;
 
     if (bind_flags & (WINED3D_BIND_SHADER_RESOURCE | WINED3D_BIND_UNORDERED_ACCESS)