xdot parsePolyline: squash -Wconversion warning

This code parses an int, but then uses it to allocate an array, so clearly
should take the error path when the parsed int is negative.

diff --git a/lib/xdot/xdot.c b/lib/xdot/xdot.c
index cdc06fb072e64ef28677dca7ad1a9d2c0c8b39d5..0311169be02be4ccc9704c6f2eab7a77c8e553be 100644 (file)
--- a/lib/xdot/xdot.c
+++ b/lib/xdot/xdot.c
@@ -92,7 +92,8 @@ static char *parsePolyline(char *s, xdot_polyline * pp)
 
     s = parseInt(s, &i);
     if (!s) return s;
-    pts = ps = gv_calloc(i, sizeof(ps[0]));
+    if (i < 0) return NULL;
+    pts = ps = gv_calloc((size_t)i, sizeof(ps[0]));
     pp->cnt = i;
     for (i = 0; i < pp->cnt; i++) {
        ps->x = strtod (s, &endp);