Only send WM_TAKE_FOCUS when the client supports it in the protocols atom

Fixes launching xterm, for example

include/client.h

@@ -31,6 +31,12 @@ void client_remove_from_container(xcb_connection_t *conn, Client *client,
  */
 void client_warp_pointer_into(xcb_connection_t *conn, Client *client);
 
+/**
+ * Returns true if the client supports the given protocol atom (like WM_DELETE_WINDOW)
+ *
+ */
+bool client_supports_protocol(xcb_connection_t *conn, Client *client, xcb_atom_t atom);
+
 /**
  * Kills the given window using WM_DELETE_WINDOW or xcb_kill_window
  *

include/data.h

@@ -444,6 +444,9 @@ struct Client {
          * one. Therefore, this flag is set when reparenting. */
         bool awaiting_useless_unmap;
 
+        /* Whether the client needs WM_TAKE_FOCUS */
+        bool needs_take_focus;
+
         /* XCB contexts */
         xcb_window_t frame;             /**< Our window: The frame around the
                                          * client */

src/client.c

@@ -74,7 +74,7 @@ void client_warp_pointer_into(xcb_connection_t *conn, Client *client) {
  * Returns true if the client supports the given protocol atom (like WM_DELETE_WINDOW)
  *
  */
-static bool client_supports_protocol(xcb_connection_t *conn, Client *client, xcb_atom_t atom) {
+bool client_supports_protocol(xcb_connection_t *conn, Client *client, xcb_atom_t atom) {
         xcb_get_property_cookie_t cookie;
         xcb_icccm_get_wm_protocols_reply_t protocols;
         bool result = false;

src/manage.c

@@ -477,6 +477,7 @@ void reparent_window(xcb_connection_t *conn, xcb_window_t child,
                 redecorate_window(conn, new);
         }
 
+        new->needs_take_focus = client_supports_protocol(conn, new, A_WM_TAKE_FOCUS);
         new->initialized = true;
 
         /* Check if the window already got the fullscreen hint set */
@@ -512,6 +513,7 @@ map:
                         }
                         if (new->container == CUR_CELL || client_is_floating(new)) {
                                 xcb_set_input_focus(conn, XCB_INPUT_FOCUS_POINTER_ROOT, new->child, XCB_CURRENT_TIME);
+                                if (new->needs_take_focus)
                                         take_focus(conn, new);
                                 ewmh_update_active_window(new->child);
                         }

src/util.c

@@ -280,6 +280,7 @@ void set_focus(xcb_connection_t *conn, Client *client, bool set_anyways) {
         CLIENT_LOG(client);
         /* Set focus to the entered window, and flush xcb buffer immediately */
         xcb_set_input_focus(conn, XCB_INPUT_FOCUS_POINTER_ROOT, client->child, XCB_CURRENT_TIME);
+        if (client->needs_take_focus)
                 take_focus(conn, client);
         ewmh_update_active_window(client->child);
         //xcb_warp_pointer(conn, XCB_NONE, client->child, 0, 0, 0, 0, 10, 10);