When converting the index buffer from 4-bytes to 2-bytes, we use the
uploader for the job. Since commit b3133e250e we do an uploader alloc
ref, which releases the uploader buffer if there is no enough space,
creating a new one.
The problem happens when we also need this buffer because it is the one
containing the index buffer to convert. This happens, for instance, if
we need to convert the primitives because they are not supported (e.g.,
converting quads to triangles), as this is done
also using the uploader.
The solution is to ensure the uploader's buffer has an extra reference
so when released, it is not destroyed. This can easily achieved by
calling first pipe_buffer_map_range(), which is required to access the
buffer, and it increases the references.
This fixes `spec@!opengl 1.1@longprim`.
Fixes: b3133e250e ("gallium: add pipe_context::resource_release to eliminate buffer refcounting")
Reviewed-by: Iago Toral Quiroga <itoral@igalia.com>
Signed-off-by: Juan A. Suarez Romero <jasuarez@igalia.com>
(cherry picked from commit 48c086cb42)
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/40752>
ec101645ff