From 6139a22bcf959f81a6bb8022a31ae9de557587b6 Mon Sep 17 00:00:00 2001
From: michl <michl@lazarus-ide.org>
Date: Wed, 5 Apr 2017 09:12:12 +0000
Subject: [PATCH] AnchorDocking: Fixed ChangeBounds loop detected. Issue #31238

git-svn-id: trunk@54525 -
---
 components/anchordocking/anchordocking.pas | 31 ++++++++++++++++++++--
 1 file changed, 29 insertions(+), 2 deletions(-)

diff --git a/components/anchordocking/anchordocking.pas b/components/anchordocking/anchordocking.pas
index a7fc9278a8..b4819c62a5 100644
--- a/components/anchordocking/anchordocking.pas
+++ b/components/anchordocking/anchordocking.pas
@@ -1465,13 +1465,40 @@ function TAnchorDockMaster.CloseUnneededControls(Tree: TAnchorDockLayoutTree
 var
   i: Integer;
   AControl: TControl;
+  TreeNodeControl: TAnchorDockLayoutTreeNode;
+
+  function ParentsIdentical: Boolean;
+  var
+    ParentForm: TCustomForm;
+    ParentAnchorDockLayoutTreeNode: TAnchorDockLayoutTreeNode;
+    Parent1, Parent2: String;
+  begin
+    ParentForm := GetParentForm(AControl, True);
+    if Assigned(ParentForm) then
+      Parent1 := ParentForm.Name
+    else
+      Parent1 := '';
+
+    Parent2 := '';
+    ParentAnchorDockLayoutTreeNode := TreeNodeControl;
+    while Assigned(ParentAnchorDockLayoutTreeNode.Parent) do begin
+      Parent2 := ParentAnchorDockLayoutTreeNode.Name;
+      ParentAnchorDockLayoutTreeNode := ParentAnchorDockLayoutTreeNode.Parent;
+    end;
+    Result := Parent1 = Parent2;
+
+//    DebugLn('TAnchorDockMaster.ParentsIdentical [', Parent1, '] [', Parent2, ']');
+  end;
+
 begin
   i:=ControlCount-1;
   while i>=0 do begin
     AControl:=Controls[i];
+    TreeNodeControl:=Tree.Root.FindChildNode(AControl.Name,true);
     if DockedControlIsVisible(AControl)
-    and (Tree.Root.FindChildNode(AControl.Name,true)=nil)
-    and (Application.MainForm<>AControl) then begin
+    and (Application.MainForm<>AControl)
+    and ((TreeNodeControl=nil) or not ParentsIdentical)
+    then begin
       DisableControlAutoSizing(AControl);
       // AControl is currently on a visible site, but not in the Tree
       // => close site