core: add function gui_buffer_search_by_id (issue #2081)

src/gui/gui-buffer.c

@@ -2860,6 +2860,26 @@ gui_buffer_search_main ()
     return NULL;
 }
 
+/*
+ * Searches for a buffer by id (unique identifier).
+ */
+
+struct t_gui_buffer *
+gui_buffer_search_by_id (long long id)
+{
+    struct t_gui_buffer *ptr_buffer;
+
+    for (ptr_buffer = gui_buffers; ptr_buffer;
+         ptr_buffer = ptr_buffer->next_buffer)
+    {
+        if (ptr_buffer->id == id)
+            return ptr_buffer;
+    }
+
+    /* buffer not found */
+    return NULL;
+}
+
 /*
  * Searches for a buffer by full name (example: "irc.libera.#weechat").
  *