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.

1 files changed, 3 insertions, 1 deletions

diff --git a/src/haiku_support.cc b/src/haiku_support.cc
index 6a270d338a2..e1aaf835689 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;
       }
    }