From dd33e98da09c487a58b6cb6693b8628c0b234a3b Mon Sep 17 00:00:00 2001
From: Simon Kelley <simon@thekelleys.org.uk>
Date: Mon, 30 Jul 2018 14:55:39 +0100
Subject: [PATCH] Fix crash parsing a --synth-domain with no prefix. Problem
 introduced in 2.79/6b2b564ac34cb3c862f168e6b1457f9f0b9ca69c

---
 CHANGELOG    | 7 +++++--
 src/option.c | 4 +++-
 2 files changed, 8 insertions(+), 3 deletions(-)

diff --git a/CHANGELOG b/CHANGELOG
index 3fe3e77..792ef3d 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -41,8 +41,11 @@ version 2.80
 	Fix missing fatal errors with some malformed options
 	(server, local, address, rebind-domain-ok, ipset, alias).
 	Thanks to Eugene Lozovoy for spotting the problem.
-	
-	
+
+	Fix crash on startup with a --synth-domain which has no prefix.
+	Introduced in 2.79. Thanks to Andreas Engel for the bug report.
+
+
 version 2.79
 	Fix parsing of CNAME arguments, which are confused by extra spaces.
 	Thanks to Diego Aguirre for spotting the bug.
diff --git a/src/option.c b/src/option.c
index 9f1b84f..c203826 100644
--- a/src/option.c
+++ b/src/option.c
@@ -2232,7 +2232,9 @@ static int one_opt(int option, char *arg, char *errstr, char *gen_err, int comma
 		      char *star;
 		      new->next = daemon->synth_domains;
 		      daemon->synth_domains = new;
-		      if ((star = strrchr(new->prefix, '*')) && *(star+1) == 0)
+		      if (new->prefix &&
+			  (star = strrchr(new->prefix, '*'))
+			  && *(star+1) == 0)
 			{
 			  *star = 0;
 			  new->indexed = 1;