Document internal use of 'above-suspended' z-group frame parameter

* src/w32fns.c (w32_dialog_in_progress, x_set_z_group):
* src/xterm.c (x_set_z_group): Clarify the internal use of
'above-suspended' when setting a frame's 'z-group' parameter.

1 files changed, 4 insertions, 0 deletions

diff --git a/src/xterm.c b/src/xterm.c
index 496effaf42a..a5646910334 100644
--- a/src/xterm.c
+++ b/src/xterm.c
@@ -10560,6 +10560,10 @@ x_set_skip_taskbar (struct frame *f, Lisp_Object new_value, Lisp_Object old_valu
  * windows that do not have the `below' property set.
  *
  * Some window managers may not honor this parameter.
+ *
+ * Internally, this function also handles a value 'above-suspended'.
+ * That value is used to temporarily remove F from the 'above' group
+ * to make sure that it does not obscure a menu currently popped up.
  */
 void
 x_set_z_group (struct frame *f, Lisp_Object new_value, Lisp_Object old_value)