4 files changed, 93 insertions, 2 deletions

diff --git a/toxcore/Messenger.c b/toxcore/Messenger.c
index 19bd7edf..73a1471c 100644
--- a/toxcore/Messenger.c
+++ b/toxcore/Messenger.c
@@ -2129,12 +2129,12 @@ uint32_t copy_friendlist(Messenger *m, int *out_list, uint32_t list_size)
     uint32_t ret = 0;
 
     for (i = 0; i < m->numfriends; i++) {
-        if (i >= list_size) {
+        if (ret >= list_size) {
             break; /* Abandon ship */
         }
 
         if (m->friendlist[i].status > 0) {
-            out_list[i] = i;
+            out_list[ret] = i;
             ret++;
         }
     }
@@ -2175,3 +2175,51 @@ int get_friendlist(Messenger *m, int **out_list, uint32_t *out_list_length)
     return 0;
 }
 
+/* Return the number of chats in the instance m.
+ * You should use this to determine how much memory to allocate
+ * for copy_chatlist. */
+uint32_t count_chatlist(Messenger *m)
+{
+    uint32_t ret = 0;
+    uint32_t i;
+    
+    for (i = 0; i < m->numchats; i++) {
+        if (m->chats[i]) {
+            ret++;
+        }
+    }
+    
+    return ret;
+}
+
+/* Copy a list of valid chat IDs into the array out_list.
+ * If out_list is NULL, returns 0.
+ * Otherwise, returns the number of elements copied.
+ * If the array was too small, the contents
+ * of out_list will be truncated to list_size. */
+uint32_t copy_chatlist(Messenger *m, int *out_list, uint32_t list_size)
+{
+    if (!out_list)
+        return 0;
+    
+    if (m->numchats == 0) {
+        return 0;
+    }
+    
+    uint32_t i;
+    uint32_t ret = 0;
+    
+    for (i = 0; i < m->numchats; i++) {
+        if (ret >= list_size) {
+            break; /* Abandon ship */
+        }
+        
+        if (m->chats[i]) {
+            out_list[ret] = i;
+            ret++;
+        }
+    }
+    
+    return ret;
+}
+
diff --git a/toxcore/Messenger.h b/toxcore/Messenger.h
index 10ac0eae..3b99b3cf 100644
--- a/toxcore/Messenger.h
+++ b/toxcore/Messenger.h
@@ -633,5 +633,17 @@ uint32_t copy_friendlist(Messenger *m, int *out_list, uint32_t list_size);
  */
 int get_friendlist(Messenger *m, int **out_list, uint32_t *out_list_length);
 
+/* Return the number of chats in the instance m.
+ * You should use this to determine how much memory to allocate
+ * for copy_chatlist. */
+uint32_t count_chatlist(Messenger *m);
+
+/* Copy a list of valid chat IDs into the array out_list.
+ * If out_list is NULL, returns 0.
+ * Otherwise, returns the number of elements copied.
+ * If the array was too small, the contents
+ * of out_list will be truncated to list_size. */
+uint32_t copy_chatlist(Messenger *m, int *out_list, uint32_t list_size);
+
 #endif
 
diff --git a/toxcore/tox.c b/toxcore/tox.c
index 6a0c6a62..5e110cbe 100644
--- a/toxcore/tox.c
+++ b/toxcore/tox.c
@@ -477,6 +477,25 @@ int tox_group_message_send(Tox *tox, int groupnumber, uint8_t *message, uint32_t
     return group_message_send(m, groupnumber, message, length);
 }
 
+/* Return the number of chats in the instance m.
+ * You should use this to determine how much memory to allocate
+ * for copy_chatlist. */
+uint32_t tox_count_chatlist(Tox *tox)
+{
+    Messenger *m = tox;
+    return count_chatlist(m);
+}
+
+/* Copy a list of valid chat IDs into the array out_list.
+ * If out_list is NULL, returns 0.
+ * Otherwise, returns the number of elements copied.
+ * If the array was too small, the contents
+ * of out_list will be truncated to list_size. */
+uint32_t tox_copy_chatlist(Tox *tox, int *out_list, uint32_t list_size)
+{
+    Messenger *m = tox;
+    return copy_chatlist(m, out_list, list_size);
+}
 
 
 /****************FILE SENDING FUNCTIONS*****************/
diff --git a/toxcore/tox.h b/toxcore/tox.h
index 5d3916b4..97fb912a 100644
--- a/toxcore/tox.h
+++ b/toxcore/tox.h
@@ -404,6 +404,18 @@ int tox_join_groupchat(Tox *tox, int friendnumber, uint8_t *friend_group_public_
  * return -1 on failure
  */
 int tox_group_message_send(Tox *tox, int groupnumber, uint8_t *message, uint32_t length);
+    
+/* Return the number of chats in the instance m.
+ * You should use this to determine how much memory to allocate
+ * for copy_chatlist. */
+uint32_t tox_count_chatlist(Tox *tox);
+
+/* Copy a list of valid chat IDs into the array out_list.
+ * If out_list is NULL, returns 0.
+ * Otherwise, returns the number of elements copied.
+ * If the array was too small, the contents
+ * of out_list will be truncated to list_size. */
+uint32_t tox_copy_chatlist(Tox *tox, int *out_list, uint32_t list_size);
 
 
 /****************FILE SENDING FUNCTIONS*****************/