input: always update the xcursor shape in pointer enter/motion events

Now that term_xcursor_update_for_seat() takes the current surface into
account (i.e. doesn’t assume the cursor is over the main grid),
there’s no longer any need to call render_xcursor_set() directly.

Thus, we can simply call term_xcursor_update_for_seat() on **all**
pointer enter and motion events. As long as we take care to update the
internal state to reflect the, possibly new, current surface before
doing so.

Also make sure to **always** reset the seat’s “current” xcursor
pointer on pointer leave events. This is done without actually sending
anything to the compositor, but is necessary to ensure that we *do*
send a request to update the xcursor on the next pointer enter event.

CHANGELOG.md

@@ -61,6 +61,7 @@
 * CSD border not being dimmed when window is not focused.
 * Visual corruption with large CSD borders
   (https://codeberg.org/dnkl/foot/issues/823).
+* Mouse cursor shape sometimes not being updated correctly.
 
 
 ### Security

input.c

@@ -1773,12 +1773,13 @@ wl_pointer_enter(void *data, struct wl_pointer *wl_pointer,
 
     xassert(tll_length(seat->mouse.buttons) == 0);
 
-    /* Scale may have changed */
-    wayl_reload_xcursor_theme(seat, term->scale);
-
     seat->mouse_focus = term;
+    term->active_surface = term_surface_kind(term, surface);
 
-    switch ((term->active_surface = term_surface_kind(term, surface))) {
+    wayl_reload_xcursor_theme(seat, term->scale); /* Scale may have changed */
+    term_xcursor_update_for_seat(term, seat);
+
+    switch (term->active_surface) {
     case TERM_SURF_GRID: {
         /*
          * Translate x,y pixel coordinate to a cell coordinate, or -1
@@ -1796,7 +1797,6 @@ wl_pointer_enter(void *data, struct wl_pointer *wl_pointer,
         else
             seat->mouse.row = (y - term->margins.top) / term->cell_height;
 
-        term_xcursor_update_for_seat(term, seat);
         break;
     }
 
@@ -1805,20 +1805,15 @@ wl_pointer_enter(void *data, struct wl_pointer *wl_pointer,
     case TERM_SURF_RENDER_TIMER:
     case TERM_SURF_JUMP_LABEL:
     case TERM_SURF_TITLE:
-        render_xcursor_set(seat, term, XCURSOR_LEFT_PTR);
-        break;
-
     case TERM_SURF_BORDER_LEFT:
     case TERM_SURF_BORDER_RIGHT:
     case TERM_SURF_BORDER_TOP:
     case TERM_SURF_BORDER_BOTTOM:
-        render_xcursor_set(seat, term, xcursor_for_csd_border(term, x, y));
         break;
 
     case TERM_SURF_BUTTON_MINIMIZE:
     case TERM_SURF_BUTTON_MAXIMIZE:
     case TERM_SURF_BUTTON_CLOSE:
-        render_xcursor_set(seat, term, XCURSOR_LEFT_PTR);
         render_refresh_csd(term);
         break;
 
@@ -1847,9 +1842,11 @@ wl_pointer_leave(void *data, struct wl_pointer *wl_pointer,
         wl_callback_destroy(seat->pointer.xcursor_callback);
         seat->pointer.xcursor_callback = NULL;
         seat->pointer.xcursor_pending = false;
-        seat->pointer.xcursor = NULL;
     }
 
+    /* Reset last-set-xcursor, to ensure we update it on a pointer-enter event */
+    seat->pointer.xcursor = NULL;
+
     /* Reset mouse state */
     seat->mouse.x = seat->mouse.y = 0;
     seat->mouse.col = seat->mouse.row = 0;
@@ -1876,7 +1873,6 @@ wl_pointer_leave(void *data, struct wl_pointer *wl_pointer,
         enum term_surface active_surface = old_moused->active_surface;
 
         old_moused->active_surface = TERM_SURF_NONE;
-        term_xcursor_update_for_seat(old_moused, seat);
 
         switch (active_surface) {
         case TERM_SURF_BUTTON_MINIMIZE:
@@ -1929,6 +1925,8 @@ wl_pointer_motion(void *data, struct wl_pointer *wl_pointer,
     seat->mouse.x = x;
     seat->mouse.y = y;
 
+    term_xcursor_update_for_seat(term, seat);
+
     enum term_surface surf_kind = term->active_surface;
     int button = 0;
     bool send_to_client = false;
@@ -1966,7 +1964,6 @@ wl_pointer_motion(void *data, struct wl_pointer *wl_pointer,
     case TERM_SURF_BORDER_RIGHT:
     case TERM_SURF_BORDER_TOP:
     case TERM_SURF_BORDER_BOTTOM:
-        render_xcursor_set(seat, term, xcursor_for_csd_border(term, x, y));
         break;
 
     case TERM_SURF_GRID: {
@@ -2017,8 +2014,6 @@ wl_pointer_motion(void *data, struct wl_pointer *wl_pointer,
         xassert(seat->mouse.col == -1 || (seat->mouse.col >= 0 && seat->mouse.col < term->cols));
         xassert(seat->mouse.row == -1 || (seat->mouse.row >= 0 && seat->mouse.row < term->rows));
 
-        term_xcursor_update_for_seat(term, seat);
-
         /* Cursor has moved to a different cell since last time */
         bool cursor_is_on_new_cell
             = old_col != seat->mouse.col || old_row != seat->mouse.row;