mesa: fix segfault in glUniformSubroutinesuiv()

From Section 7.9 (SUBROUTINE UNIFORM VARIABLES) of the OpenGL
4.5 Core spec:

   "The command

       void UniformSubroutinesuiv(enum shadertype, sizei count,
                                  const uint *indices);

   will load all active subroutine uniforms for shader stage
   shadertype with subroutine indices from indices, storing
   indices[i] into the uniform at location i. The indices for
   any locations between zero and the value of
   ACTIVE_SUBROUTINE_UNIFORM_LOCATIONS minus one which are not
   used will be ignored."

V2: simplify NULL check suggested by Jason.

Acked-by: Jason Ekstrand <jason@jlekstrand.net>
Reviewed-by: Dave Airlie <airlied@redhat.com>
Cc: "11.0 11.1" mesa-stable@lists.freedesktop.org
https://bugs.freedesktop.org/show_bug.cgi?id=93731

1 files changed, 10 insertions, 0 deletions

diff --git a/src/mesa/main/shaderapi.c b/src/mesa/main/shaderapi.c
index cdc85f3..126786c 100644
--- a/src/mesa/main/shaderapi.c
+++ b/src/mesa/main/shaderapi.c
@@ -2530,6 +2530,11 @@ _mesa_UniformSubroutinesuiv(GLenum shadertype, GLsizei count,
    i = 0;
    do {
       struct gl_uniform_storage *uni = sh->SubroutineUniformRemapTable[i];
+      if (uni == NULL) {
+         i++;
+         continue;
+      }
+
       int uni_count = uni->array_elements ? uni->array_elements : 1;
       int j, k;
 
@@ -2557,6 +2562,11 @@ _mesa_UniformSubroutinesuiv(GLenum shadertype, GLsizei count,
    i = 0;
    do {
       struct gl_uniform_storage *uni = sh->SubroutineUniformRemapTable[i];
+      if (uni == NULL) {
+         i++;
+         continue;
+      }
+
       int uni_count = uni->array_elements ? uni->array_elements : 1;
 
       memcpy(&uni->storage[0], &indices[i],