From bff41e1f5d0e346933fb1f639586cad9302ab061 Mon Sep 17 00:00:00 2001
From: Bart <9132501-flyingsheep@users.noreply.gitlab.com>
Date: Sat, 29 Jul 2023 23:29:53 +0200
Subject: [PATCH] TTaskDialog: In Execute, use the Handle of the current active
 form for the ParentWnd parameter. Based upon the documentation of Delphi:
 https://docwiki.embarcadero.com/Libraries/Alexandria/en/Vcl.Dialogs.TCustomTaskDialog.Execute
 It makes Execute honour the tfRelativeToWindow flag.

---
 lcl/include/taskdialog.inc | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/lcl/include/taskdialog.inc b/lcl/include/taskdialog.inc
index a63b6c20da..5b749e088c 100644
--- a/lcl/include/taskdialog.inc
+++ b/lcl/include/taskdialog.inc
@@ -181,8 +181,18 @@ begin
 end;
 
 function TCustomTaskDialog.Execute: Boolean;
+var
+  AParentWnd: HWND;
 begin
-  Result := Execute(0);
+  //See: https://docwiki.embarcadero.com/Libraries/Alexandria/en/Vcl.Dialogs.TCustomTaskDialog.Execute
+  //If no handle is supplied, then the handle of the active form should be used.
+  //For that Delphi uses Application.ActiveFormHandle (the docs say so).
+  //Currently TApplication does not have a ActiveFormHandle property, so we use our own code for that.
+  if Assigned(Screen.ActiveCustomForm) then
+    AParentWnd := Screen.ActiveCustomForm.Handle
+  else
+    AParentWnd := 0;
+  Result := Execute(AParentWnd);
 end;
 
 procedure TCustomTaskDialog.SetButtons(const Value: TTaskDialogButtons);