From 2caae76ebb4133564eb760f9627b3ea97793225d Mon Sep 17 00:00:00 2001
From: rich2014 <rich2014.git@outlook.com>
Date: Wed, 13 Sep 2023 22:17:04 +0800
Subject: [PATCH] Fix #40505: Merge branch 'lhelp/iphtml'

---
 components/turbopower_ipro/iphtml.pas  | 16 ++++++++++++++--
 lcl/interfaces/cocoa/cocoawscommon.pas |  3 +++
 2 files changed, 17 insertions(+), 2 deletions(-)

diff --git a/components/turbopower_ipro/iphtml.pas b/components/turbopower_ipro/iphtml.pas
index 7a8dac5326..3e42e4c91f 100644
--- a/components/turbopower_ipro/iphtml.pas
+++ b/components/turbopower_ipro/iphtml.pas
@@ -5502,15 +5502,21 @@ begin
 end;
 
 function TIpHtmlInternalPanel.DoMouseWheel(Shift: TShiftState; WheelDelta: Integer; MousePos: TPoint): Boolean;
+const
+  WHEEL_DELTA = 120;
 var
   i: Integer;
 begin
-  Result:=inherited DoMouseWheel(Shift, WheelDelta, MousePos);
-  for i := 0 to Mouse.WheelScrollLines-1 do
+  inherited DoMouseWheel(Shift, WheelDelta, MousePos);
+  for i := abs(Mouse.WheelScrollLines * WheelDelta div WHEEL_DELTA) downto 0 do
     if WheelDelta < 0 then
       Perform(LM_VSCROLL, MAKELONG(SB_LINEDOWN, 0), 0)
     else
       Perform(LM_VSCROLL, MAKELONG(SB_LINEUP, 0), 0);
+
+  // should always return true to confirm that
+  // the MouseWheel Event is handled by TIpHtmlInternalPanel
+  Result:= true;
 end;
 
 procedure TIpHtmlInternalPanel.Paint;
@@ -5899,13 +5905,19 @@ end;
 procedure TIpHtmlInternalPanel.WMHScroll(var Message: TLMHScroll);
 begin
   if HScroll.Visible then
+  begin
     HScroll.ScrollMessage(Message);
+    Message.Result := 1;
+  end;
 end;
 
 procedure TIpHtmlInternalPanel.WMVScroll(var Message: TLMVScroll);
 begin
   if VScroll.Visible then
+  begin
     VScroll.ScrollMessage(Message);
+    Message.Result := 1;
+  end;
 end;
 
 procedure TIpHtmlInternalPanel.AsyncHotInvoke(data: ptrint);
diff --git a/lcl/interfaces/cocoa/cocoawscommon.pas b/lcl/interfaces/cocoa/cocoawscommon.pas
index 1bcb3689f3..ad0df68c6c 100644
--- a/lcl/interfaces/cocoa/cocoawscommon.pas
+++ b/lcl/interfaces/cocoa/cocoawscommon.pas
@@ -1355,8 +1355,11 @@ begin
     wheelDelta := round(-event.scrollingDeltaX * 120);
   end
   else
+  begin
     // Filter out empty events - See bug 28491
+    Result := true;
     Exit;
+  end;
 
   // Filter scrolls that affect both X and Y towards whatever the last scroll was
   FLastWheelWasHorz := (Msg.Msg = LM_MOUSEHWHEEL);