From: Jeremy Harris <jgh146exb@wizmail.org>
Date: Thu, 7 Jun 2018 15:24:31 +0000 (+0100)
Subject: ARC: Fix signing for case when DKIM signing failed
X-Git-Tag: exim-4.92-RC1~173
X-Git-Url: https://git.exim.org/exim.git/commitdiff_plain/7b9822bffe67da2a43a82d12caf5db00a3ed71c2

ARC: Fix signing for case when DKIM signing failed
---

diff --git a/doc/doc-txt/ChangeLog b/doc/doc-txt/ChangeLog
index 881d24c25..36f2d7048 100644
--- a/doc/doc-txt/ChangeLog
+++ b/doc/doc-txt/ChangeLog
@@ -49,6 +49,9 @@ JH/08 When generating a selfsigned cert, use serial number 1 since zero is not
 JH/09 Bug 2274: Fix logging of cmdline args when starting in an unlinked cwd.
       Previously this would segfault.
 
+JH/10 Fix ARC signing for case when DKIM signing failed.  Previously this would
+      segfault.
+
 
 Exim version 4.91
 -----------------
diff --git a/src/src/arc.c b/src/src/arc.c
index dd2ad51b0..466c13990 100644
--- a/src/src/arc.c
+++ b/src/src/arc.c
@@ -1705,7 +1705,7 @@ if (g)
 
 /* Finally, append the dkim headers and return the lot. */
 
-g = string_catn(g, sigheaders->s, sigheaders->ptr);
+if (sigheaders) g = string_catn(g, sigheaders->s, sigheaders->ptr);
 (void) string_from_gstring(g);
 gstring_reset_unused(g);
 return g;