ofz#46165 avoid a divide by zero seen fuzzing libreoffice rendering

1 files changed, 6 insertions, 1 deletions

diff --git a/src/cairo-pen.c b/src/cairo-pen.c
index 9bf960423..a4b84aae5 100644
--- a/src/cairo-pen.c
+++ b/src/cairo-pen.c
@@ -289,7 +289,12 @@ _cairo_pen_vertices_needed (double	    tolerance,
     } else if (tolerance >= major_axis) {
 	num_vertices = 4;
     } else {
-	num_vertices = ceil (2*M_PI / acos (1 - tolerance / major_axis));
+	double divisor = acos (1 - tolerance / major_axis);
+
+	if (divisor == 0.0)
+	    return 4;
+
+	num_vertices = ceil (2*M_PI / divisor);
 
 	/* number of vertices must be even */
 	if (num_vertices % 2)