Fix known-roster-item bug

If you got a second roster description (e.g. after a reconnect) the
roster items were just appended. There was no distinction if a roster
item already existed or not. This lead to doubled entries.

This commit ignores already known roster items. Mind that it is still
not able to update an existing item. This is mentioned by a FIXME
comment.

1 files changed, 21 insertions, 1 deletions

diff --git a/data.c b/data.c
index f8be1ff..f19075c 100644
--- a/data.c
+++ b/data.c
@@ -3,6 +3,7 @@
 #include <string.h>
 #include <stdlib.h>
 #include <stdio.h>
+#include <stdbool.h>
 
 #include "gui.h"
 #include "data.h"
@@ -11,10 +12,29 @@
 static roster_item_t* roster = NULL;
 
 
+/* check if JID is already in roster data structure */
+bool is_jid_known(const char* jid) {
+
+	roster_item_t* i;
+
+	// iterate over all roster items
+	for (i = roster; i != NULL; i=i->next) {
+		if (strcmp(i->jid, jid) == 0) {
+			return true;
+		}
+	}
+
+	return false;
+
+}
+
 void data_add_roster_item(const char* jid, const char* subscription,
                           const char* name) {
 
-	// FIXME check if roster item already exists and handle updates
+	// FIXME handle roster updates
+	if (is_jid_known(jid)) {
+		return;
+	}
 
 	// allocate datastructures
 	roster_item_t* item = malloc(sizeof(roster_item_t));