tgsi: Verify constants are set before attempting to read them.

diff --git a/src/gallium/auxiliary/tgsi/tgsi_exec.c b/src/gallium/auxiliary/tgsi/tgsi_exec.c
index fb573fe..df00293 100644 (file)
--- a/src/gallium/auxiliary/tgsi/tgsi_exec.c
+++ b/src/gallium/auxiliary/tgsi/tgsi_exec.c
@@ -957,6 +957,7 @@ fetch_src_file_channel(
    case TGSI_EXTSWIZZLE_W:
       switch( file ) {
       case TGSI_FILE_CONSTANT:
+         assert(mach->Consts);
          chan->f[0] = mach->Consts[index->i[0]][swizzle];
          chan->f[1] = mach->Consts[index->i[1]][swizzle];
          chan->f[2] = mach->Consts[index->i[2]][swizzle];