[PATCH] cliptest: Avoid use of uninitialized memory when regions don't intersect

[Derek Foreman]

Prevent attempting to draw the intersection polygon when it contains no
vertices.

Signed-off-by: Derek Foreman <derekf at osg.samsung.com>
---
 clients/cliptest.c | 12 +++++++-----
 1 file changed, 7 insertions(+), 5 deletions(-)

diff --git a/clients/cliptest.c b/clients/cliptest.c
index a1928f4..dd0ea5c 100644
--- a/clients/cliptest.c
+++ b/clients/cliptest.c
@@ -570,12 +570,14 @@ draw_geometry(cairo_t *cr, struct weston_surface
*surface,
 	cairo_set_source_rgba(cr, 0.0, 0.0, 1.0, 0.4);
 	cairo_fill(cr);

-	draw_polygon_closed(cr, ex, ey, n);
-	cairo_set_source_rgb(cr, 0.0, 1.0, 0.0);
-	cairo_stroke(cr);
+	if (n) {
+		draw_polygon_closed(cr, ex, ey, n);
+		cairo_set_source_rgb(cr, 0.0, 1.0, 0.0);
+		cairo_stroke(cr);

-	cairo_set_source_rgba(cr, 0.0, 1.0, 0.0, 0.5);
-	draw_polygon_labels(cr, ex, ey, n);
+		cairo_set_source_rgba(cr, 0.0, 1.0, 0.0, 0.5);
+		draw_polygon_labels(cr, ex, ey, n);
+	}
 }

 static void
-- 
2.1.0.rc1