minor changes required in fpg_tree.pas to work with FPC 2.3.1

1 files changed, 4 insertions, 2 deletions

diff --git a/src/gui/fpg_tree.pas b/src/gui/fpg_tree.pas
index 94c524d0..86377dff 100644
--- a/src/gui/fpg_tree.pas
+++ b/src/gui/fpg_tree.pas
@@ -1670,14 +1670,16 @@ begin
     i := (GetNodeHeightSum * GetNodeHeight) - VisibleHeight + FHScrollbar.Height;
     if FYOffset > i then
       FYOffset := i;
-    inc(FVScrollbar.Position, FScrollWheelDelta);
+    i := FVScrollbar.Position + FScrollWheelDelta;
+    FVScrollbar.Position := i;
   end
   else
   begin
     dec(FYOffset, FScrollWheelDelta);
     if FYOffset < 0 then
       FYOffset := 0;
-    dec(FVScrollbar.Position, FScrollWheelDelta);
+    i := FVScrollbar.Position - FScrollWheelDelta;
+    FVScrollbar.Position := i;
   end;
   UpdateScrollbars;
   RePaint;