u_vbuf_mgr: fix max_index computation when src_offset is abused as buffer_offset

1 files changed, 6 insertions, 1 deletions

diff --git a/src/gallium/auxiliary/util/u_vbuf_mgr.c b/src/gallium/auxiliary/util/u_vbuf_mgr.c
index a034483ee5c..04149525ea7 100644
--- a/src/gallium/auxiliary/util/u_vbuf_mgr.c
+++ b/src/gallium/auxiliary/util/u_vbuf_mgr.c
@@ -581,7 +581,12 @@ static void u_vbuf_mgr_compute_max_index(struct u_vbuf_mgr_priv *mgr)
        * for that when dividing by stride. */
       unused = vb->stride -
                (mgr->ve->ve[i].src_offset + mgr->ve->src_format_size[i]);
-      assert(unused >= 0);
+
+      /* If src_offset is greater than stride (which means it's a buffer
+       * offset rather than a vertex offset)... */
+      if (unused < 0) {
+         unused = 0;
+      }
 
       /* Compute the maximum index for this vertex element. */
       max_index =