From c3e8aa2edff6559abf45f43df5bde550b97d1200 Mon Sep 17 00:00:00 2001
From: maxim <maxim@lazarus-ide.org>
Date: Fri, 16 Oct 2020 23:39:29 +0000
Subject: [PATCH] Reverted r64007 #0c525d9222 from branches/fixes_2_0 (LCL win:
 detect wincontrol destroy during WindProc / fixes Issue #28404) because it
 caused crashes

git-svn-id: branches/fixes_2_0@64032 -
---
 lcl/interfaces/win32/win32callback.inc | 40 +-------------------------
 1 file changed, 1 insertion(+), 39 deletions(-)

diff --git a/lcl/interfaces/win32/win32callback.inc b/lcl/interfaces/win32/win32callback.inc
index 282ccb1fea..cfd5607517 100644
--- a/lcl/interfaces/win32/win32callback.inc
+++ b/lcl/interfaces/win32/win32callback.inc
@@ -294,8 +294,6 @@ type
   TAccessCustomEdit = class(TCustomEdit);
 
   TWindowProcHelper = class
-  private
-    procedure SetlWinControl(AValue: TWinControl);
   private
     // WindowProc parameters
     Window: HWnd;            // DWord / QWord
@@ -305,7 +303,7 @@ type
     // Other variables
     LMessage: TLMessage;
     PLMsg: PLMessage;
-    FlWinControl: TWinControl;
+    lWinControl: TWinControl;
     WinProcess: Boolean;
     NotifyUserInput: Boolean;
     WindowInfo: PWin32WindowInfo;
@@ -372,16 +370,7 @@ type
     procedure UpdateLMMovePos(X, Y: Smallint);
     procedure UpdateUIState(CharCode: Word);
     function DoWindowProc: LResult;    // Called from the actual WindowProc.
-    property lWinControl: TWinControl read FlWinControl write SetlWinControl;
   end;
-  PWindowProcHelper = ^TWindowProcHelper;
-
-  { TWindProcNotificationReceiver }
-
-  TWindProcNotificationReceiver = class
-    procedure ReceiveDestroyNotify(Sender: TObject);
-  end;
-
 
 // Implementation of TWindowProcHelper
 
@@ -500,18 +489,6 @@ begin
   {$endif}
 end;
 
-procedure TWindowProcHelper.SetlWinControl(AValue: TWinControl);
-begin
-  if FlWinControl = AValue then Exit;
-  if FlWinControl <> nil then
-    FlWinControl.RemoveHandlerOnBeforeDestruction(@TWindProcNotificationReceiver(@Self).ReceiveDestroyNotify);
-
-  FlWinControl := AValue;
-
-  if FlWinControl <> nil then
-    FlWinControl.AddHandlerOnBeforeDestruction(@TWindProcNotificationReceiver(@Self).ReceiveDestroyNotify);
-end;
-
 procedure TWindowProcHelper.CalcClipRgn(PaintRegion: HRGN);
 var
   nSize: DWORD;
@@ -1949,14 +1926,6 @@ begin
   end;
 end;
 
-{ TWindProcNotificationReceiver }
-
-procedure TWindProcNotificationReceiver.ReceiveDestroyNotify(Sender: TObject);
-begin
-  assert(PWindowProcHelper(Self)^.FlWinControl = Sender, 'TWindProcNotificationReceiver.ReceiveDestroyNotify: PWindowProcHelper(Self)^.FlWinControl = Sender');
-  PWindowProcHelper(Self)^.lWinControl := nil;
-end;
-
 // This is called from the actual WindowProc.
 
 function TWindowProcHelper.DoWindowProc: LResult;
@@ -1976,7 +1945,6 @@ const
   WM_DPICHANGED = $02E0;
 {$ENDIF}
 begin
-  try
   FillChar(LMessage, SizeOf(LMessage), 0);
   PLMsg := @LMessage;
   WinProcess := True;
@@ -1989,7 +1957,6 @@ begin
   end else begin
     lWinControl := WindowInfo^.WinControl;
   end;
-
   if (IgnoreNextCharWindow <> 0) and ((Msg = WM_CHAR) or (Msg = WM_SYSCHAR)) then
   begin
     if IgnoreNextCharWindow = Window then
@@ -2676,10 +2643,6 @@ begin
   else if PLMsg = @LMNotify     then Result := LMNotify.Result
   else if PLMsg = @LMMouseEvent then Result := LMMouseEvent.Result
   else                               Result := PLMsg^.Result;
-
-  finally
-    lWinControl := nil;
-  end;
 end;
 
 {------------------------------------------------------------------------------
@@ -2714,7 +2677,6 @@ begin
   finally
     Helper.Free;
   end;
-  Helper.lWinControl := nil;
 end;
 
 {$ifdef MSG_DEBUG}