Fix minor problem with scroll bar grabs on Haiku

* haiku_support.cc (class EmacsScrollBar, EmacsScrollBar)
(MouseDown, MouseUp): Keep a counter of the mouse down events
received.

1 files changed, 8 insertions, 7 deletions

diff --git a/src/haiku_support.cc b/src/haiku_support.cc
index 204fdb81c2d..cb378d2d810 100644
--- a/src/haiku_support.cc
+++ b/src/haiku_support.cc
@@ -1996,8 +1996,9 @@ public:
   float old_value;
   scroll_bar_info info;
 
-  /* True if button events should be passed to the parent.  */
-  bool handle_button;
+  /* How many button events were passed to the parent without
+     release.  */
+  int handle_button_count;
   bool in_overscroll;
   bool can_overscroll;
   bool maybe_overscroll;
@@ -2013,7 +2014,7 @@ public:
     : BScrollBar (BRect (x, y, x1, y1), NULL, NULL, 0, 0, horizontal_p ?
                   B_HORIZONTAL : B_VERTICAL),
       dragging (0),
-      handle_button (false),
+      handle_button_count (0),
       in_overscroll (false),
       can_overscroll (false),
       maybe_overscroll (false),
@@ -2234,10 +2235,10 @@ public:
 
     if (message && (message->FindInt32 ("modifiers", &mods)
                     == B_OK)
-        && mods & B_CONTROL_KEY && !handle_button)
+        && mods & B_CONTROL_KEY)
       {
         /* Allow C-mouse-3 to split the window on a scroll bar.   */
-        handle_button = true;
+        handle_button_count += 1;
         SetMouseEventMask (B_POINTER_EVENTS, (B_SUSPEND_VIEW_FOCUS
                                               | B_LOCK_WINDOW_FOCUS));
         parent->BasicMouseDown (ConvertToParent (pt), this, message);
@@ -2309,9 +2310,9 @@ public:
     in_overscroll = false;
     maybe_overscroll = false;
 
-    if (handle_button)
+    if (handle_button_count)
       {
-        handle_button = false;
+        handle_button_count--;
         looper = Looper ();
         msg = (looper
                ? looper->CurrentMessage ()