fixed memory leaks

Also avoided several NULL pointer dereferences.

src/xmpp/presence.c

@@ -156,14 +156,23 @@ presence_sub_request_find(char * search_str)
 gboolean
 presence_sub_request_exists(const char * const bare_jid)
 {
-    GSList *requests = autocomplete_get_list(sub_requests_ac);
+    gboolean result = FALSE;
+    GSList *requests_p = autocomplete_get_list(sub_requests_ac);
+    GSList *requests = requests_p;
+
     while (requests != NULL) {
         if (strcmp(requests->data, bare_jid) == 0) {
-            return TRUE;
+            result = TRUE;
+            break;
         }
         requests = g_slist_next(requests);
     }
-    return FALSE;
+
+    if (requests_p != NULL) {
+        g_slist_free_full(requests_p, free);
+    }
+
+    return result;
 }
 
 void
@@ -220,20 +229,28 @@ presence_update(const resource_presence_t presence_type, const char * const msg,
 static void
 _send_room_presence(xmpp_conn_t *conn, xmpp_stanza_t *presence)
 {
-    GList *rooms = muc_get_active_room_list();
+    GList *rooms_p = muc_get_active_room_list();
+    GList *rooms = rooms_p;
+
     while (rooms != NULL) {
         const char *room = rooms->data;
         const char *nick = muc_get_room_nick(room);
-        char *full_room_jid = create_fulljid(room, nick);
 
-        xmpp_stanza_set_attribute(presence, STANZA_ATTR_TO, full_room_jid);
-        log_debug("Sending presence to room: %s", full_room_jid);
-        xmpp_send(conn, presence);
-        free(full_room_jid);
+        if (nick != NULL) {
+            char *full_room_jid = create_fulljid(room, nick);
+
+            xmpp_stanza_set_attribute(presence, STANZA_ATTR_TO, full_room_jid);
+            log_debug("Sending presence to room: %s", full_room_jid);
+            xmpp_send(conn, presence);
+            free(full_room_jid);
+        }
 
         rooms = g_list_next(rooms);
     }
-    g_list_free(rooms);
+
+    if (rooms_p != NULL) {
+        g_list_free(rooms_p);
+    }
 }
 
 void
@@ -347,9 +364,13 @@ _subscribe_handler(xmpp_conn_t * const conn,
     xmpp_stanza_t * const stanza, void * const userdata)
 {
     char *from = xmpp_stanza_get_attribute(stanza, STANZA_ATTR_FROM);
-    Jid *from_jid = jid_create(from);
     log_debug("Subscribe presence handler fired for %s", from);
 
+    Jid *from_jid = jid_create(from);
+    if (from_jid == NULL) {
+        return 1;
+    }
+
     prof_handle_subscription(from_jid->barejid, PRESENCE_SUBSCRIBE);
     autocomplete_add(sub_requests_ac, strdup(from_jid->barejid));
 
@@ -368,6 +389,11 @@ _unavailable_handler(xmpp_conn_t * const conn,
 
     Jid *my_jid = jid_create(jid);
     Jid *from_jid = jid_create(from);
+    if (my_jid == NULL || from_jid == NULL) {
+        jid_destroy(my_jid);
+        jid_destroy(from_jid);
+        return 1;
+    }
 
     char *status_str = stanza_get_status(stanza, NULL);
 
@@ -420,6 +446,11 @@ _available_handler(xmpp_conn_t * const conn,
 
     Jid *my_jid = jid_create(jid);
     Jid *from_jid = jid_create(from);
+    if (my_jid == NULL || from_jid == NULL) {
+        jid_destroy(my_jid);
+        jid_destroy(from_jid);
+        return 1;
+    }
 
     char *show_str = stanza_get_show(stanza, "online");
     char *status_str = stanza_get_status(stanza, NULL);
@@ -515,6 +546,10 @@ _get_caps_key(xmpp_stanza_t * const stanza)
 
     log_debug("Presence contains capabilities.");
 
+    if (node == NULL) {
+        return NULL;
+    }
+
     // xep-0115
     if ((hash_type != NULL) && (strcmp(hash_type, "sha-1") == 0)) {
         log_debug("Hash type %s supported.", hash_type);
@@ -544,6 +579,8 @@ _get_caps_key(xmpp_stanza_t * const stanza)
         g_string_free(id_str, TRUE);
     }
 
+    g_free(node);
+
     return caps_key;
 }
 
@@ -626,6 +663,7 @@ _room_presence_handler(xmpp_conn_t * const conn, xmpp_stanza_t * const stanza,
                 if (old_nick != NULL) {
                     muc_add_to_roster(room, nick, show_str, status_str, caps_key);
                     prof_handle_room_member_nick_change(room, old_nick, nick);
+                    free(old_nick);
                 } else {
                     if (!muc_nick_in_roster(room, nick)) {
                         prof_handle_room_member_online(room, nick, show_str, status_str, caps_key);