decrease the current vertex count by 1 if an uneven number of vertices is copied by _tnl_copy_vertices. Otherwise, since in this case it will copy an extra vertex to avoid problems with vertex order in the new buffer, one triangle will be drawn twice. This fixes bug #9062.

1 files changed, 5 insertions, 0 deletions

diff --git a/src/mesa/tnl/t_vtx_exec.c b/src/mesa/tnl/t_vtx_exec.c
index 57d842f05fe..900c4ab6cc1 100644
--- a/src/mesa/tnl/t_vtx_exec.c
+++ b/src/mesa/tnl/t_vtx_exec.c
@@ -239,6 +239,11 @@ static GLuint _tnl_copy_vertices( GLcontext *ctx )
 	 return 2;
       }
    case GL_TRIANGLE_STRIP:
+      /* no parity issue, but need to make sure the tri is not drawn twice */
+      if (nr & 1) {
+	 tnl->vtx.prim[tnl->vtx.prim_count-1].count--;
+      }
+      /* fallthrough */
    case GL_QUAD_STRIP:
       switch (nr) {
       case 0: ovf = 0; break;