wayland: implement pointer grab for icon drag-and-move

Implement wl_pointer_grab (type 3 WM policy grab) that suppresses
client pointer focus delivery during WM-internal drags while letting
WME_MOTION events flow to WMMaskEvent. Implement wl_pointer_ungrab
and wl_pointer_change_cursor (maps WCUR_* to xcursor names).

Fix button release handler to not terminate type 3 grabs early —
the policy code calls pointer_ungrab itself.

Fix overlay surface blocking hit-testing: the iconify animation's
full-screen overlay (WL_LAYER_OVERLAY) was left enabled after the
animation completed, causing wlr_scene_node_at to hit it instead of
frame_bufs. Now server_ungrab disables the overlay node after flush.

src/appicon.c

@@ -806,6 +806,7 @@ Bool wHandleAppIconMove(WAppIcon *aicon, WMEvent *event)
 	while (1) {
 		WMMaskEvent(scr->wmscreen, PointerMotionMask | ButtonReleaseMask | ButtonPressMask
 			    | ButtonMotionMask | ExposureMask | EnterWindowMask, &ev);
+		wwarning("wHandleAppIconMove: got event type=%d", ev.type);
 		switch (ev.type) {
 		case WME_EXPOSE:
 			WMHandleEvent(&ev);

src/backend/wayland/wl_backend.c

@@ -409,8 +409,12 @@ struct wl_compositor_state {
     int                             sigfd;
     struct wl_event_source         *sigfd_source;
     /* Phase 22: interactive move/resize grab state.
-     * grab_type: 0=none, 1=move, 2=resize.
+     * grab_type: 0=none, 1=move, 2=resize, 3=WM policy grab.
-     * grab_view: the toplevel being moved/resized (NULL when grab_type==0).
+     * Type 3 is used by wl_pointer_grab for WM-internal drags (dock icons,
+     * app icons, menus).  It suppresses wl_update_pointer_focus (so client
+     * surfaces don't steal pointer events) but does NOT intercept motion —
+     * WME_MOTION events flow normally to the WMMaskEvent loop.
+     * grab_view: the toplevel being moved/resized (NULL when grab_type==0 or 3).
      * grab_start_ptr_{x,y}: pointer position when grab started.
      * grab_start_win_{x,y,w,h}: window geometry when grab started.
      * grab_resize_edges: WL_SHELL_SURFACE_RESIZE_* bitmask (resize only). */
@@ -5130,10 +5134,12 @@ handle_pointer_button(struct wl_listener *listener, void *data)
     struct wlr_pointer_button_event *ev = data;
     if (!wl_state.seat)
         return;
-    /* Phase 22: any button release ends an active grab. */
+    /* Phase 22: any button release ends an active compositor grab (move/resize).
-    if (wl_state.grab_type &&
+     * Type 3 (WM policy grab) is NOT ended here — the policy code calls
+     * pointer_ungrab itself after processing the button release event. */
+    if (wl_state.grab_type && wl_state.grab_type != 3 &&
         ev->state == WLR_BUTTON_RELEASED) {
-        wwarning("wl_backend: grab ended (button release)");
+        wwarning("wl_backend: grab ended (button release) grab_type=%d", wl_state.grab_type);
         wl_grab_end();
         wl_update_pointer_focus(ev->time_msec);
         return;
@@ -5233,12 +5239,33 @@ wl_pointer_grab(WNativeWindow grab_win, WNativeWindow confine_to,
                 unsigned int event_mask, int cursor_id,
                 int owner_events, unsigned long timestamp)
 {
-    (void)grab_win; (void)confine_to; (void)event_mask;
+    (void)confine_to; (void)event_mask;
-    (void)cursor_id; (void)owner_events; (void)timestamp;
+    (void)timestamp; (void)grab_win;
-    return 0;
+    wwarning("wl_pointer_grab: win=0x%lx owner_events=%d cursor_id=%d grab_type_before=%d",
+             grab_win, owner_events, cursor_id, wl_state.grab_type);
+    /* Only set up a WM policy grab (type 3) for actual drags (owner_events=True).
+     * Brief protective grabs (e.g., during icon creation) don't need to suppress
+     * pointer focus — they just need to return success. */
+    if (owner_events) {
+        wl_state.grab_type = 3;
+        wl_state.grab_view = NULL;
+        if (wl_state.seat)
+            wlr_seat_pointer_clear_focus(wl_state.seat);
+    }
+    if (cursor_id > 0)
+        wl_set_cursor_image("left_ptr");
+    return 1; /* success */
 }
 
-static void wl_pointer_ungrab(unsigned long timestamp) { (void)timestamp; }
+static void wl_pointer_ungrab(unsigned long timestamp)
+{
+    (void)timestamp;
+    wwarning("wl_pointer_ungrab: grab_type=%d", wl_state.grab_type);
+    if (wl_state.grab_type == 3) {
+        wl_state.grab_type = 0;
+        wl_state.grab_view = NULL;
+    }
+}
 
 /* ------------------------------------------------------------------ */
 /* Phase 13: pointer focus delivery to Wayland surfaces               */
@@ -5690,6 +5717,8 @@ overlay_flush(void)
         wm_shm_surface_commit(s, _op, 0, 0);
     }
     if (s->scene_buf) {
+        /* Ensure the node is visible for the animation frame. */
+        wlr_scene_node_set_enabled(&s->scene_buf->node, true);
         /* Notify wlroots that the pixel data has changed. */
         wlr_scene_buffer_set_buffer(s->scene_buf, &s->wlr_buf);
     }
@@ -5704,7 +5733,16 @@ overlay_flush(void)
 /* ------------------------------------------------------------------ */
 
 static void wl_server_grab(void) {}   /* no-op: Wayland double-buffers for us */
-static void wl_server_ungrab(void) { overlay_flush(); }
+static void wl_server_ungrab(void)
+{
+    overlay_flush();
+    /* Disable the overlay scene node so it doesn't intercept hit-testing.
+     * The XOR animation has already erased its pixels; leaving the node
+     * enabled blocks frame_buf_at (wlr_scene_node_at hits the overlay
+     * before any frame_buf). */
+    if (wl_state.overlay_surf && wl_state.overlay_surf->scene_buf)
+        wlr_scene_node_set_enabled(&wl_state.overlay_surf->scene_buf->node, false);
+}
 
 /* ------------------------------------------------------------------ */
 /* Stacking                                                            */
@@ -7931,7 +7969,20 @@ static int wl_noop_cursor_create_from_files(WScreen *scr, const char *bitmap_pat
 { (void)scr; (void)bitmap_path; (void)mask_path; (void)cursor_out; return 0; }
 static void wl_noop_cursor_free(Cursor cursor) { (void)cursor; }
 static void wl_noop_cursor_set(WNativeWindow window, Cursor cursor) { (void)window; (void)cursor; }
-static void wl_noop_pointer_change_cursor(int cursor_id) { (void)cursor_id; }
+static void wl_pointer_change_cursor(int cursor_id)
+{
+    const char *name;
+    switch (cursor_id) {
+    case 1: /* WCUR_MOVE */    name = "fleur";       break;
+    case 2: /* WCUR_RESIZE */  name = "bottom_right_corner"; break;
+    case 7: /* WCUR_WAIT */    name = "watch";       break;
+    case 8: /* WCUR_ARROW */   name = "left_ptr";    break;
+    case 9: /* WCUR_QUESTION */name = "question_arrow"; break;
+    case 10:/* WCUR_TEXT */    name = "xterm";       break;
+    default:                   name = "left_ptr";    break;
+    }
+    wl_set_cursor_image(name);
+}
 static void wl_noop_appicon_paint_dock_dots(WAppIcon *aicon, void *wapp)
 { (void)aicon; (void)wapp; }
 
@@ -8217,7 +8268,7 @@ const WMBackend wl_backend = {
     .cursor_create_from_files = wl_noop_cursor_create_from_files,
     .cursor_free            = wl_noop_cursor_free,
     .cursor_set             = wl_noop_cursor_set,
-    .pointer_change_cursor  = wl_noop_pointer_change_cursor,
+    .pointer_change_cursor  = wl_pointer_change_cursor,
     .appicon_paint_dock_dots = wl_noop_appicon_paint_dock_dots,
     .pixmap_get_size        = wl_noop_pixmap_get_size,
     .icon_paint_title_bg    = wl_noop_icon_paint_title_bg,

src/dock.c

@@ -3899,6 +3899,10 @@ static void iconMouseDown(WObjDescriptor *desc, WBackendEvent *event)
 	WDock *dock = aicon->dock;
 	WScreen *scr = aicon->icon->core->screen_ptr;
 
+	wwarning("iconMouseDown: aicon=%p dock=%p button=%d xindex=%d yindex=%d",
+		 (void*)aicon, (void*)dock, event->u.button.button,
+		 aicon->xindex, aicon->yindex);
+
 	if (aicon->editing || WCHECK_STATE(WSTATE_MODAL))
 		return;