master 141a06334e: Fix expose events in non-double-buffered child frames on Haiku

[Po Lu]

branch: master
commit 141a06334ecd92286b731125589832f161f03e11
Author: Po Lu <luangruo@yahoo.com>
Commit: Po Lu <luangruo@yahoo.com>

    Fix expose events in non-double-buffered child frames on Haiku
    
    * src/haiku_support.cc (EmacsShow): Set shown_flag to 1 only if
    this view is double buffered.
    (TearDownDoubleBuffering): Clear shown_flag.
---
 src/haiku_support.cc | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/src/haiku_support.cc b/src/haiku_support.cc
index 6a270d338a..e1aaf83568 100644
--- a/src/haiku_support.cc
+++ b/src/haiku_support.cc
@@ -739,7 +739,7 @@ public:
        was_shown_p = true;
       }
 
-    if (this->parent)
+    if (this->parent && offscreen_draw_view)
       shown_flag = 1;
     Show ();
     if (this->parent)
@@ -994,6 +994,8 @@ public:
        offscreen_draw_view = NULL;
        delete offscreen_draw_bitmap_1;
        offscreen_draw_bitmap_1 = NULL;
+
+       shown_flag = 0;
       }
    }