Position popup menu shown from keyboard correctly in wxGTK

Don't always show it at (-1, -1) and avoid GTK errors like

Gdk-CRITICAL **: gdk_window_get_device_position_double: assertion
'gdk_device_get_source (device) != GDK_SOURCE_KEYBOARD' failed

See wxWidgets#24522.

(cherry picked from commit 95d1413)

Author: vadz

docs/changes.txt

@@ -300,6 +300,7 @@ wxGTK:
 - Make GTKSuppressDiagnostics(), broken since 3.2.1, work again (#24432).
 - Fix wxTE_PROCESS_ENTER in wxGTK comboboxes with autocomplete (#24394).
 - Fix -Wdeprecated-copy-dtor warnings in the headers with gcc 14 (#24502).
+- Position popup menu shown from keyboard correctly (#24522).
 
 wxMSW:
 

src/gtk/window.cpp

@@ -6114,7 +6114,20 @@ bool wxWindowGTK::DoPopupMenu( wxMenu *menu, int x, int y )
             event = (GdkEvent*)&eventTmp;
         }
         if (x == -1 && y == -1)
-            gdk_window_get_device_position(window, device, &x, &y, NULL);
+        {
+            if (gdk_device_get_source(device) == GDK_SOURCE_KEYBOARD)
+            {
+                // We can't get the position from this device in this case, as
+                // gdk_window_get_device_position() would just fail with a
+                // "critical" error, so use the global mouse position instead:
+                // it should be what we want anyhow.
+                wxGetMousePosition(&x, &y);
+            }
+            else
+            {
+                gdk_window_get_device_position(window, device, &x, &y, NULL);
+            }
+        }
 
         const GdkRectangle rect = { x, y, 1, 1 };
         gtk_menu_popup_at_rect(GTK_MENU(menu->m_menu),