Fix SIGSEGV if no pre-existing nickname information

Loading an xml file with dive computer information without any
preexisting nickname data would try to "remember" that NULL nickname.
Causing a SIGSEGV if there was no nickname information.

The bug was introduced by commit ec38d3708df2 ("Move device_info handling
into a new 'device.c' file") when I inadvertently removed a bit too much
code. It actually wants to remember a missing DC nickname as an empty one.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>

1 files changed, 3 insertions, 0 deletions

diff --git a/gtk-gui.c b/gtk-gui.c
index 60dde0399..d096e7e90 100644
--- a/gtk-gui.c
+++ b/gtk-gui.c
@@ -1737,6 +1737,9 @@ void remember_dc(const char *model, uint32_t deviceid, const char *nickname, gbo
 	if (!nn_entry)
 		return;
 
+	if (!nickname)
+		nickname = "";
+
 	/* No existing nickname? */
 	if (!nn_entry->nickname) {
 		char buffer[160];