From 9f4b4c975a5425eaabcc6e10e432d86a3d26fb83 Mon Sep 17 00:00:00 2001
From: Benno Schulenberg <bensberg@justemail.net>
Date: Sat, 4 Jun 2016 09:30:41 +0200
Subject: [PATCH] files: prevent dereferencing a possible (although very
 unlikely) NULL

Don't catch the NULL earlier, because we do want an error message when
opening the lockfile fails.
---
 src/files.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/src/files.c b/src/files.c
index 4da3aeba..ccf1f2a2 100644
--- a/src/files.c
+++ b/src/files.c
@@ -252,7 +252,8 @@ int write_lockfile(const char *lockfilename, const char *origfilename, bool modi
     snprintf(&lockdata[2], 11, "nano %s", VERSION);
     strncpy(&lockdata[28], mypwuid->pw_name, 16);
     strncpy(&lockdata[68], myhostname, 31);
-    strncpy(&lockdata[108], origfilename, 768);
+    if (origfilename != NULL)
+	strncpy(&lockdata[108], origfilename, 768);
     if (modified == TRUE)
 	lockdata[1007] = 0x55;