From: Ralph Corderoy <ralph@inputplus.co.uk>
Date: Sat, 29 Jul 2017 14:06:11 +0000 (+0100)
Subject: dtimezone(): Explain abs(3) is undefined on INT_MIN.
X-Git-Url: https://diplodocus.org/git/nmh/commitdiff_plain/4a56a28ac439137ba2b71fcb5952b4e4abd1e2fc?ds=inline;hp=1dd139e04f59bbfa3a310c2776c4bb2e2fdf1fdd

dtimezone(): Explain abs(3) is undefined on INT_MIN.

That's why a negative int is flipped over into unsigned by assuming
two's complement.
---

diff --git a/sbr/dtime.c b/sbr/dtime.c
index 3a51d87f..b3ca012a 100644
--- a/sbr/dtime.c
+++ b/sbr/dtime.c
@@ -291,7 +291,7 @@ char *dtimezone(int offset, int flags)
     unsigned os, hours, mins;
 
     pos = offset >= 0;
-    os = pos ? offset : ~offset + 1;
+    os = pos ? offset : ~offset + 1; /* abs(3) undefined on INT_MIN. */
     hours = os / 60;
     mins = os % 60;