From: Matthew Fernandez <matthew.fernandez@gmail.com>
Date: Wed, 6 Jul 2022 00:24:05 +0000 (-0700)
Subject: cgraph: rephrase ID comparison in 'agraphidcmpf'
X-Git-Tag: 5.0.1~46^2~1
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=94b0d63c995eacb54170b0ee2754d85ca1abfb21;p=graphviz

cgraph: rephrase ID comparison in 'agraphidcmpf'

Avoids a possible integer overflow and squashes a -Wsign-conversion warning.
---

diff --git a/lib/cgraph/graph.c b/lib/cgraph/graph.c
index 1e2223a4d..a2f1aacb2 100644
--- a/lib/cgraph/graph.c
+++ b/lib/cgraph/graph.c
@@ -239,11 +239,15 @@ static int agraphidcmpf(Dict_t * d, void *arg0, void *arg1, Dtdisc_t * disc)
 {
     (void)d; /* unused */
     (void)disc; /* unused */
-    ptrdiff_t	v;
     Agraph_t *sg0 = arg0;
     Agraph_t *sg1 = arg1;
-    v = (AGID(sg0) - AGID(sg1));
-    return ((v==0)?0:(v<0?-1:1));
+    if (AGID(sg0) < AGID(sg1)) {
+	return -1;
+    }
+    if (AGID(sg0) > AGID(sg1)) {
+	return 1;
+    }
+    return 0;
 }
 
 Dtdisc_t Ag_subgraph_id_disc = {