From f14ddd7eeacdab264360c4a8686bdce8b92b9d06 Mon Sep 17 00:00:00 2001
From: zeljan1 <zeljko@holobit.hr>
Date: Fri, 7 Feb 2025 15:52:07 +0100
Subject: [PATCH] Gtk3: fixed ClientHeight does not equal to Height on
 wayland.Patch by Anton Kavalenka. issue #41345

---
 lcl/interfaces/gtk3/gtk3widgets.pas | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/lcl/interfaces/gtk3/gtk3widgets.pas b/lcl/interfaces/gtk3/gtk3widgets.pas
index b54e3dbdd7..de56bef444 100644
--- a/lcl/interfaces/gtk3/gtk3widgets.pas
+++ b/lcl/interfaces/gtk3/gtk3widgets.pas
@@ -8875,8 +8875,13 @@ begin
   end;
   {$ENDIF}
 
-  NewSize.cx := AGdkRect^.width;
-  NewSize.cy := AGdkRect^.height;
+  if decoration_flags(TCustomForm(Actl.LCLObject))<>[] then
+    PGtkWIndow(Actl.widget)^.get_size(@newSize.cx, @newsize.cy)
+  else
+  begin
+    NewSize.cx := AGdkRect^.width;
+    NewSize.cy := AGdkRect^.height;
+  end;
 
   //writeln(format('Gkt3SizeAllocate w=%d h=%d',[NewSize.cx,NewSize.cy]));