Divecomputer entries with deviceid 0 should be ignored for nicknames

Those only come from a number of development versions of Subsurface that
didn't include the deviceid in the divecomputer entry. There is no way of
telling different dive computers (of the same model) apart, so assigning a
nickname to such an entry then creates incorrect output when loading an
XML file from someone else (e.g. Linus and I both have a Uemis SDA and
both may have entries for our own SDA with deviceid 0; then the nickname
Subsurface shows for any Uemis SDA entry with a deviceid of 0 depends on
whether I last loaded his XML file or mine; that makes no sense).

This should only affect the develoers who stored XML files with one of the
development version of Subsurface that didn't store deviceids.

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

1 files changed, 17 insertions, 2 deletions

diff --git a/gtk-gui.c b/gtk-gui.c
index 35bfd5116..974cfe29d 100644
--- a/gtk-gui.c
+++ b/gtk-gui.c
@@ -2051,6 +2051,11 @@ void set_filename(const char *filename, gboolean force)
 static struct dcnicknamelist *get_dc_nicknameentry(const char *model, int deviceid)
 {
 	struct dcnicknamelist *known = nicknamelist;
+
+	/* a 0 deviceid doesn't get a nickname - those come from development
+	 * versions of Subsurface that didn't store the deviceid in the divecomputer entries */
+	if (!deviceid)
+		return NULL;
 	if (!model)
 		model = "";
 	while (known) {
@@ -2077,6 +2082,11 @@ const char *get_dc_nickname(const char *model, uint32_t deviceid)
 static struct dcnicknamelist *get_different_dc_nicknameentry(const char *model, int deviceid)
 {
 	struct dcnicknamelist *known = nicknamelist;
+
+	/* a 0 deviceid matches any DC of the same model - those come from development
+	 * versions of Subsurface that didn't store the deviceid in the divecomputer entries */
+	if (!deviceid)
+		return NULL;
 	if (!model)
 		model = "";
 	while (known) {
@@ -2163,6 +2173,11 @@ bail:
 
 void remember_dc(const char *model, uint32_t deviceid, const char *nickname, gboolean change_conf)
 {
+	/* we don't want to record entries with a deviceid of 0; those are from earlier
+	 * development versions of Subsurface before we stored the hash in the divecomputer
+	 * entries... we don't know which actual divecomputer those entries are from */
+	if (!deviceid)
+		return;
 	if (!nickname)
 		nickname = "";
 	if (!get_dc_nickname(model, deviceid)) {
@@ -2273,8 +2288,8 @@ void add_dc_to_string(char **dc_xml, struct divecomputer *dc)
 	const char *nickname;
 	int len;
 
-	if (!dc || !dc->model || !*dc->model)
-		/* we have no dc or no model information... nothing to do here */
+	if (!dc || !dc->model || !*dc->model || !dc->deviceid)
+		/* we have no dc or no model or no deviceid information... nothing to do here */
 		return;
 	len = sizeof(" model='' deviceid=''") + strlen(dc->model) + 8;
 	pattern = malloc(len);