Merge branch 'blender-v4.5-release'

source/blender/windowmanager/WM_api.hh

@@ -166,7 +166,19 @@ const char *WM_ghost_backend();
 enum eWM_CapabilitiesFlag {
   /** Ability to warp the cursor (set its location). */
   WM_CAPABILITY_CURSOR_WARP = (1 << 0),
-  /** Ability to access window positions & move them. */
+  /**
+   * Window position access, support for the following.
+   * - Getting window positions.
+   * - Setting window positions.
+   * - Setting positions for new windows.
+   *
+   * Currently there is no need to distinguish between these different cases
+   * so a single flag is used.
+   *
+   * When omitted, it isn't possible to know where windows are located in relation to each other.
+   * Operations such as applying events from one window to another or detecting the non-active
+   * window under the cursor are not supported.
+   */
   WM_CAPABILITY_WINDOW_POSITION = (1 << 1),
   /**
    * The windowing system supports a separate primary clipboard

source/blender/windowmanager/intern/wm_window.cc

@@ -2672,6 +2672,18 @@ wmWindow *WM_window_find_under_cursor(wmWindow *win,
                                       const int event_xy[2],
                                       int r_event_xy_other[2])
 {
+  if ((WM_capabilities_flag() & WM_CAPABILITY_WINDOW_POSITION) == 0) {
+    /* Window positions are unsupported, so this function can't work as intended.
+     * Perform the bare minimum, return the active window if the event is within it. */
+    rcti rect;
+    WM_window_rect_calc(win, &rect);
+    if (!BLI_rcti_isect_pt_v(&rect, event_xy)) {
+      return nullptr;
+    }
+    copy_v2_v2_int(r_event_xy_other, event_xy);
+    return win;
+  }
+
   int temp_xy[2];
   copy_v2_v2_int(temp_xy, event_xy);
   wm_cursor_position_to_ghost_screen_coords(win, &temp_xy[0], &temp_xy[1]);