Obey ICCCM 4.1.5 / 4.2.3

When a window is moved, it should be sent a synthetic ConfigureNotify describing
its new position. This also documents why we send a synthetic event if nothing
was changed in response to a ConfigureRequest.

Signed-off-by: Uli Schlachter <psychon@znc.in>

event.c

@@ -275,6 +275,7 @@ event_handle_configurerequest(xcb_configure_request_event_t *ev)
         }
 
         if(!client_resize(c, geometry, false))
+            /* ICCCM 4.1.5 / 4.2.3, if nothing was changed, send an event saying so */
             xwindow_configure(c->window, geometry, c->border_width);
     }
     else

objects/client.c

@@ -732,9 +732,14 @@ client_resize(client_t *c, area_t geometry, bool hints)
        || c->geometry.width != geometry.width
        || c->geometry.height != geometry.height)
     {
+        bool send_notice = false;
         screen_t *new_screen = screen_getbycoord(c->screen,
                                                  geometry.x, geometry.y);
 
+        if(c->geometry.width == geometry.width
+           && c->geometry.height == geometry.height)
+            send_notice = true;
+
         /* Also store geometry including border */
         c->geometry = geometry;
 
@@ -748,6 +753,10 @@ client_resize(client_t *c, area_t geometry, bool hints)
                 XCB_CONFIG_WINDOW_X | XCB_CONFIG_WINDOW_Y | XCB_CONFIG_WINDOW_WIDTH | XCB_CONFIG_WINDOW_HEIGHT,
                 (uint32_t[]) { geometry.x, geometry.y, geometry.width, geometry.height });
 
+        if(send_notice)
+            /* We are moving without changing the size, see ICCCM 4.2.3 */
+            xwindow_configure(c->window, geometry, c->border_width);
+
         client_restore_enterleave_events();
 
         screen_client_moveto(c, new_screen, false);