generic attribute 0 wasn't handled correctly (Jesse Allen)
diff --git a/src/mesa/shader/arbprogparse.c b/src/mesa/shader/arbprogparse.c
index b596b79..cdf1b3d 100644
--- a/src/mesa/shader/arbprogparse.c
+++ b/src/mesa/shader/arbprogparse.c
@@ -1538,12 +1538,20 @@
                GLuint attrib;
                if (!parse_generic_attrib_num(ctx, inst, Program, &attrib)) {
                   *is_generic = 1;
+                  if (attrib >= MAX_VERTEX_PROGRAM_ATTRIBS) {
+                     const char *msg = "Invalid generic vertex attribute reference";
+                     _mesa_set_program_error (ctx, Program->Position, msg);
+                     _mesa_error (ctx, GL_INVALID_OPERATION, msg);
+                     return 1;
+                  }
                   /* Add VERT_ATTRIB_GENERIC0 here because ARB_vertex_program's
                    * attributes do not alias the conventional vertex
                    * attributes.
                    */
                   if (attrib > 0)
                      *inputReg = attrib + VERT_ATTRIB_GENERIC0;
+                  else
+                     *inputReg = 0;
                }
             }
             break;