mesa: fix reuse of deleted sampler object

Deleting a sampler object will only cause it to be unbound from the
current context. To avoid reusing something that it still bound in
another context we need to check the DeletePending flag first.

Reviewed-by: Marek Olšák <marek.olsak@amd.com>
Reviewed-by: Pierre-Eric Pelloux-Prayer <pierre-eric.pelloux-prayer@amd.com>
Fixes: 842c9130 ("mesa: enable GL name reuse by default for all drivers except virgl")
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/34091>
(cherry picked from commit 9bb696588d)

.pick_status.json

@@ -4084,7 +4084,7 @@
         "description": "mesa: fix reuse of deleted sampler object",
         "nominated": true,
         "nomination_type": 2,
-        "resolution": 0,
+        "resolution": 1,
         "main_sha": null,
         "because_sha": "842c91300fd041cf35398d05d2995f16d76870ae",
         "notes": null

src/mesa/main/mtypes.h

@@ -889,6 +889,8 @@ struct gl_sampler_object
 
    uint8_t glclamp_mask; /**< mask of GL_CLAMP wraps active */
 
+   bool DeletePending; /**< true if sampler object is removed from the hash */
+
    /** GL_ARB_bindless_texture */
    bool HandleAllocated;
    struct util_dynarray Handles;

src/mesa/main/samplerobj.c

@@ -265,6 +265,8 @@ delete_samplers(struct gl_context *ctx, GLsizei count, const GLuint *samplers)
                }
             }
 
+            sampObj->DeletePending = true;
+
             /* The ID is immediately freed for re-use */
             _mesa_HashRemoveLocked(&ctx->Shared->SamplerObjects, samplers[i]);
             /* But the object exists until its reference count goes to zero */
@@ -402,7 +404,8 @@ bind_samplers(struct gl_context *ctx, GLuint first, GLsizei count,
          struct gl_sampler_object *sampObj;
 
          if (samplers[i] != 0) {
-            if (currentSampler && currentSampler->Name == samplers[i])
+            if (currentSampler && !currentSampler->DeletePending &&
+                currentSampler->Name == samplers[i])
                sampObj = currentSampler;
             else
                sampObj = lookup_samplerobj_locked(ctx, samplers[i]);