st/mesa: check for dummy programs in destroy_program_variants()

When we destroy an ARB vp/fp whose ID was gen'd but not otherwise used we
get a pointer to the dummy/placeholder program.  We can't destroy that one
so just skip it.  This only failed during context tear-down because
glDeleteProgramsARB() was already aware of dummy programs.

Fixes https://bugs.freedesktop.org/show_bug.cgi?id=38086

Note: This is a candidate for the stable branches.

Tested-by: Andreas Boll <andreas.boll.dev@gmail.com>

diff --git a/src/mesa/state_tracker/st_program.c b/src/mesa/state_tracker/st_program.c
index a9111b5..f56f7cb 100644 (file)
--- a/src/mesa/state_tracker/st_program.c
+++ b/src/mesa/state_tracker/st_program.c
@@ -1142,7 +1142,7 @@ st_print_shaders(struct gl_context *ctx)
 static void
 destroy_program_variants(struct st_context *st, struct gl_program *program)
 {
-   if (!program)
+   if (!program || program == &_mesa_DummyProgram)
       return;
 
    switch (program->Target) {