glsl: Guard against NULL dereference

This trivially corrects mesa 3ca1c221, which introduced a check that
crashes when a match is not found.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=95005
Fixes: piglit.spec.glsl-1_50.compiler.interface-blocks-name-reused-globally-4.vert
Reviewed-by: Alejandro Piñeiro <apinheiro@igalia.com>

diff --git a/src/compiler/glsl/ast_to_hir.cpp b/src/compiler/glsl/ast_to_hir.cpp
index ecfe684a0f47a58f4df10cd49dc70e521a738a95..a524fbdc56fe2eefc5586f87ac08bad847268f0b 100644 (file)
--- a/src/compiler/glsl/ast_to_hir.cpp
+++ b/src/compiler/glsl/ast_to_hir.cpp
@@ -6920,7 +6920,7 @@ ast_struct_specifier::hir(exec_list *instructions,
    if (!state->symbols->add_type(name, t)) {
       const glsl_type *match = state->symbols->get_type(name);
       /* allow struct matching for desktop GL - older UE4 does this */
-      if (state->is_version(130, 0) && match->record_compare(t, false))
+      if (match != NULL && state->is_version(130, 0) && match->record_compare(t, false))
          _mesa_glsl_warning(& loc, state, "struct `%s' previously defined", name);
       else
          _mesa_glsl_error(& loc, state, "struct `%s' previously defined", name);