screen: fix tag removal/add

Signed-off-by: Julien Danjou <julien@danjou.info>

screen.c

@@ -366,7 +366,7 @@ luaA_screen_module_index(lua_State *L)
     return luaA_pushscreen(L, &globalconf.screens.tab[screen]);
 }
 
-/** Get or set screen tags.
+/** Get screen tags.
  * \param L The Lua VM state.
  * \return The number of elements pushed on stack.
  * \luastack
@@ -377,23 +377,16 @@ luaA_screen_module_index(lua_State *L)
 static int
 luaA_screen_tags(lua_State *L)
 {
-    int i;
     screen_t *s = luaL_checkudata(L, 1, "screen");
 
     if(lua_gettop(L) == 2)
     {
         luaA_checktable(L, 2);
 
-        /* remove current tags */
-        foreach(tag, s->tags)
-            tag_set_screen(*tag, NULL);
+        /* Detach all tags, but go backward since the array len will change */
+        for(int i = s->tags.len - 1; i >= 0; i--)
+            tag_remove_from_screen(s->tags.tab[i]);
 
-        tag_array_wipe(&s->tags);
-        tag_array_init(&s->tags);
-
-        s->need_reban = true;
-
-        /* push new tags */
         lua_pushnil(L);
         while(lua_next(L, 2))
             tag_append_to_screen(L, -1, s);
@@ -401,7 +394,7 @@ luaA_screen_tags(lua_State *L)
     else
     {
         lua_createtable(L, s->tags.len, 0);
-        for(i = 0; i < s->tags.len; i++)
+        for(int i = 0; i < s->tags.len; i++)
         {
             luaA_object_push(L, s->tags.tab[i]);
             lua_rawseti(L, -2, i + 1);

tag.c

@@ -121,7 +121,10 @@ tag_append_to_screen(lua_State *L, int udx, screen_t *s)
 
     /* can't attach a tag twice */
     if(tag->screen)
+    {
+        lua_remove(L, udx);
         return;
+    }
 
     int screen_index = screen_array_indexof(&globalconf.screens, s);
     int phys_screen = screen_virttophys(screen_index);
@@ -152,9 +155,12 @@ tag_append_to_screen(lua_State *L, int udx, screen_t *s)
 /** Remove a tag from screen. Tag must be on a screen and have no clients.
  * \param tag The tag to remove.
  */
-static void
+void
 tag_remove_from_screen(tag_t *tag)
 {
+    if(!tag->screen)
+        return;
+
     int screen_index = screen_array_indexof(&globalconf.screens, tag->screen);
     int phys_screen = screen_virttophys(screen_index);
     tag_array_t *tags = &tag->screen->tags;
@@ -431,8 +437,7 @@ luaA_tag_set_screen(lua_State *L, tag_t *tag)
         luaA_checkscreen(screen);
     }
 
-    if(tag->screen)
-        tag_remove_from_screen(tag);
+    tag_remove_from_screen(tag);
 
     if(screen != -1)
         tag_append_to_screen(L, -3, &globalconf.screens.tab[screen]);

tag.h

@@ -30,6 +30,7 @@ void untag_client(client_t *, tag_t *);
 bool is_client_tagged(client_t *, tag_t *);
 void tag_view_only_byindex(screen_t *, int);
 void tag_append_to_screen(lua_State *, int, screen_t *);
+void tag_remove_from_screen(tag_t *);
 void tag_unref_simplified(tag_t **);
 
 ARRAY_FUNCS(tag_t *, tag, tag_unref_simplified)
@@ -38,7 +39,6 @@ void tag_class_setup(lua_State *);
 
 bool tag_get_selected(tag_t *);
 char *tag_get_name(tag_t *);
-void tag_set_screen(tag_t *, screen_t *);
 
 #endif
 // vim: filetype=c:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:encoding=utf-8:textwidth=80