linker: Wrap access of producer_var with a NULL check

producer_var could be NULL if consumer_var is not NULL and
consumer_is_fs is false.  This will occur when the producer is NULL and
the consumer is the geometry shader for a program that contains only a
geometry shader.  This will occur starting with the next patch.

Signed-off-by: Ian Romanick <[email protected]>
Cc: [email protected]
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=82585
Reviewed-by: Jordan Justen <[email protected]>
(cherry picked from commit 5eca78a00a5de442aaf541a1095d5cfa6b4f45de)
Nominated-by: Ian Romanick <[email protected]>

1 files changed, 5 insertions, 3 deletions

diff --git a/src/glsl/link_varyings.cpp b/src/glsl/link_varyings.cpp
index 54ceae1b9eb..fb5c9092050 100644
--- a/src/glsl/link_varyings.cpp
+++ b/src/glsl/link_varyings.cpp
@@ -830,9 +830,11 @@ varying_matches::record(ir_variable *producer_var, ir_variable *consumer_var)
        * regardless of where they appear.  We can trivially satisfy that
        * requirement by changing the interpolation type to flat here.
        */
-      producer_var->data.centroid = false;
-      producer_var->data.sample = false;
-      producer_var->data.interpolation = INTERP_QUALIFIER_FLAT;
+      if (producer_var) {
+         producer_var->data.centroid = false;
+         producer_var->data.sample = false;
+         producer_var->data.interpolation = INTERP_QUALIFIER_FLAT;
+      }
 
       if (consumer_var) {
          consumer_var->data.centroid = false;