master 43618cd44c: Find a way to make lowering frames work on Haiku

[Po Lu]

branch: master
commit 43618cd44c44568947732aacfe99919f25202343
Author: Po Lu <luangruo@yahoo.com>
Commit: Po Lu <luangruo@yahoo.com>

    Find a way to make lowering frames work on Haiku
    
    * doc/lispref/frames.texi (Raising and Lowering): Document that
    lowering frames is now supported on Haiku.
    * src/haikuterm.c (haiku_frame_raise_lower): Implement a hack to
    lower frames.
---
 doc/lispref/frames.texi | 6 ++----
 src/haikuterm.c         | 7 +++++++
 2 files changed, 9 insertions(+), 4 deletions(-)

diff --git a/doc/lispref/frames.texi b/doc/lispref/frames.texi
index ca7d9ada0b..2eeb8b7ed7 100644
--- a/doc/lispref/frames.texi
+++ b/doc/lispref/frames.texi
@@ -3154,10 +3154,8 @@ raises @var{frame} above all other child frames of its 
parent.
 @deffn Command lower-frame &optional frame
 This function lowers frame @var{frame} (default, the selected frame)
 below all other frames belonging to the same or a higher z-group as
-@var{frame}.@footnote{Lowering frames is not supported on Haiku, due
-to limitations imposed by the system.}  If @var{frame} is a child
-frame (@pxref{Child Frames}), this lowers @var{frame} below all other
-child frames of its parent.
+@var{frame}.  If @var{frame} is a child frame (@pxref{Child Frames}),
+this lowers @var{frame} below all other child frames of its parent.
 @end deffn
 
 @defun frame-restack frame1 frame2 &optional above
diff --git a/src/haikuterm.c b/src/haikuterm.c
index 3e99cc1c8d..ad89985b74 100644
--- a/src/haikuterm.c
+++ b/src/haikuterm.c
@@ -370,6 +370,13 @@ haiku_frame_raise_lower (struct frame *f, bool raise_p)
       BWindow_sync (FRAME_HAIKU_WINDOW (f));
       unblock_input ();
     }
+  else
+    {
+      block_input ();
+      BWindow_send_behind (FRAME_HAIKU_WINDOW (f), NULL);
+      BWindow_sync (FRAME_HAIKU_WINDOW (f));
+      unblock_input ();
+    }
 }
 
 /* Unfortunately, NOACTIVATE is not implementable on Haiku.  */