neatogen cmpIpair: rephrase comparator to avoid arithmetic

cccb8b1d22a18031fc92d93133c7fa14ef7e1361 fixed an integer overflow in a
`memcmp`-/`strcmp`-like comparator. The same situation exists in the code
touched in this commit. Rather than wait for an edge case to expose an overflow
here, this change makes the same update, removing arithmetic and the consequent
possibility of overflow.

diff --git a/lib/neatogen/multispline.c b/lib/neatogen/multispline.c
index 44d6a9f270acb8891730f84031d98cf369b096c7..f8cfcaa65be1ac68e0b605c3e18bfcd8f3a34d34 100644 (file)
--- a/lib/neatogen/multispline.c
+++ b/lib/neatogen/multispline.c
@@ -170,7 +170,13 @@ static int cmpIpair(Dt_t * d, int *p1, int *p2, Dtdisc_t * disc)
     (void)d;
     (void)disc;
 
-    return (*p1 - *p2);
+    if (*p1 < *p2) {
+        return -1;
+    }
+    if (*p1 > *p2) {
+        return 1;
+    }
+    return 0;
 }
 
 static void *newIpair(Dt_t * d, Ipair * objp, Dtdisc_t * disc)