From 30e9e11e8c5c05467710ad8cefdb15be0c48a436 Mon Sep 17 00:00:00 2001
From: bart <9132501-flyingsheep@users.noreply.gitlab.com>
Date: Fri, 4 Jan 2019 11:20:10 +0000
Subject: [PATCH] LCL: TCustomTabControl: don't fire OnChanging when
 programatically changing TabIndex/PageIndex. Patch by Michl. Issue #0033720.

git-svn-id: trunk@59985 -
---
 lcl/include/customnotebook.inc | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lcl/include/customnotebook.inc b/lcl/include/customnotebook.inc
index 0da7ac09c0..cf0aef9387 100644
--- a/lcl/include/customnotebook.inc
+++ b/lcl/include/customnotebook.inc
@@ -581,7 +581,7 @@ begin
   if (AValue < -1) or (AValue >= PageCount) then Exit;
   //debugln('TCustomTabControl.SetPageIndex A ',dbgsName(Self),' AValue=',dbgs(AValue),' fPageIndex=',dbgs(fPageIndex),' PageCount=',dbgs(PageCount),' HandleAllocated=',dbgs(HandleAllocated),' ',dbgs(ComponentState));
   if FPageIndex = AValue then exit;
-  if not CanChangePageIndex then exit;
+  if (nboDoChangeOnSetIndex in Options) and (not CanChangePageIndex) then exit;  //Delphi does not call CanChange either
   //debugln('TCustomTabControl.SetPageIndex B ',dbgsName(Self),' AValue=',dbgs(AValue),' fPageIndex=',dbgs(fPageIndex),' PageCount=',dbgs(PageCount),' HandleAllocated=',dbgs(HandleAllocated));
 
   InternalSetPageIndex(AValue);