Avoid crash in env.c/host_fqdn if we cannot canonicalize our own hostname.

Reported by Alexander Holler.

svn path=/branches/BRANCH_6-3/; revision=4908

2 files changed, 3 insertions, 1 deletions

diff --git a/NEWS b/NEWS
index 118104d3..107045c3 100644
--- a/NEWS
+++ b/NEWS
@@ -108,6 +108,8 @@ fetchmail 6.3.5 (not yet released):
 * ignore SIGPIPE signals and rely on functions to return EPIPE instead. This is
   necessary because the former longjmp() from the signal handler is unsafe and
   makes the whole fetchmail behavior undefined after the event.
+* Avoid crash in env.c/host_fqdn if we cannot canonicalize our own hostname.
+  Reported by Alexander Holler.
 
 # CHANGES:
 * Rename all fetchmail-internal lock_* functions to fm_lock_*. Obsoletes
diff --git a/env.c b/env.c
index 9b9e608c..f9a3bf9a 100644
--- a/env.c
+++ b/env.c
@@ -176,7 +176,7 @@ char *host_fqdn(int required)
 	    }
 	}
 
-	result = xstrdup(res->ai_canonname);
+	result = xstrdup(res->ai_canonname ? res->ai_canonname : tmpbuf);
 	fm_freeaddrinfo(res);
     }
     else