Mesa (master): st/vega: Fix a crash with empty paths.

[Chia-I Wu]

Module: Mesa
Branch: master
Commit: 9ea4936a36f5011695a3996c63cfad6b480b3e49
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=9ea4936a36f5011695a3996c63cfad6b480b3e49

Author: Chia-I Wu <olv at lunarg.com>
Date:   Wed Nov 24 16:29:10 2010 +0800

st/vega: Fix a crash with empty paths.

---

 src/gallium/state_trackers/vega/path.c |   13 +++++++++++--
 1 files changed, 11 insertions(+), 2 deletions(-)

diff --git a/src/gallium/state_trackers/vega/path.c b/src/gallium/state_trackers/vega/path.c
index 05f8b0d..31c718e 100644
--- a/src/gallium/state_trackers/vega/path.c
+++ b/src/gallium/state_trackers/vega/path.c
@@ -312,7 +312,15 @@ static void polygon_array_calculate_bounds( struct polygon_array *polyarray )
    unsigned i;
 
    assert(polys);
-   assert(polys->num_elements);
+
+   if (!polys->num_elements) {
+      polyarray->min_x = 0.0f;
+      polyarray->min_y = 0.0f;
+      polyarray->max_x = 0.0f;
+      polyarray->max_y = 0.0f;
+      return;
+   }
+
    polygon_bounding_rect((((struct polygon**)polys->data)[0]), bounds);
    min_x = bounds[0];
    min_y = bounds[1];
@@ -362,7 +370,8 @@ static struct polygon_array * path_get_fill_polygons(struct path *p, struct matr
 
    sx = sy = px = py = ox = oy = 0.f;
 
-   current = polygon_create(32);
+   if (p->num_segments)
+      current = polygon_create(32);
 
    for (i = 0; i < p->num_segments; ++i) {
       VGubyte segment = ((VGubyte*)(p->segments->data))[i];