[Lazarus] Menu editor unstable? - stack trace

[Michael Van Canneyt]

On Wed, 10 May 2017, Mattias Gaertner via Lazarus wrote:

> On Wed, 10 May 2017 00:06:35 +0200 (CEST)
> Michael Van Canneyt via Lazarus <lazarus at lists.lazarus-ide.org> wrote:
>
>> [...]
>> > I have tested here:
>> > 64bit Linux Mint 18.1 Cinnamon, GTK2 version 2.24.30, Lazarus 1.9.0 
>> > r54844 FPC 3.0.2 x86_64-linux-gtk2 
>> 
>> This is the exact version I am using. (lazarus SVN version may differ, but
>> it is the day before yesterday's SVN version)
>> 
>> >
>> > Maybe it is a problem with your GTK2 version?
>> > Maybe it is a problem with your OS? 
>> 
>> They are the same as yours.
>
> Maybe the bug is not in the menu editor, but in an installed package
> and the menu editor is only the symptom?
> Try uninstalling all unneeded packages. Does that change anything?

I created a minimal IDE without any additional packages installed ('make all'). 
Latest SVN.  Revision 54848. (I did an svn update). FPC 3.0.2. 
No defines are set when building the IDE

And I still get the error, I did as I outlined before. I waited 5 (five!)
seconds before clicking on the newly added item. That should eliminate 
any possible timing issues.

I remind you that the LCL *warns* that something is wrong:

WARNING: TShadowItem.Destroy with LCLRefCount>0. Hint: Maybe the component is processing an event?

This line alone should IMHO be enough to tell the IDE people that something
is actually going wrong.

Below is the output on the console when I do the steps as I outlined them
above.

I have reported it as a bug.
https://bugs.freepascal.org/view.php?id=31791

Michael.

TObjectInspectorDlg.FillPersistentComboBox: Updating ComboBox with components
WARNING: TShadowItem.Destroy with LCLRefCount>0. Hint: Maybe the component is processing an event?
Hint: (lazarus) TMainIDE.OnPropHookDeletePersistent A MenuItem14:TMenuItem
TObjectInspectorDlg.FillPersistentComboBox: Updating ComboBox with components
Hint: (lazarus) TMainIDE.OnPropHookDeletePersistent A MenuItem13:TMenuItem
TObjectInspectorDlg.FillPersistentComboBox: Updating ComboBox with components
Hint: (lazarus) TMainIDE.OnPropHookDeletePersistent A MenuItem12:TMenuItem
TObjectInspectorDlg.FillPersistentComboBox: Updating ComboBox with components
Hint: (lazarus) TMainIDE.OnPropHookDeletePersistent A MenuItem11:TMenuItem
TObjectInspectorDlg.FillPersistentComboBox: Updating ComboBox with components
WARNING: TShadowItem.Destroy with LCLRefCount>0. Hint: Maybe the component is processing an event?
TApplication.HandleException Access violation
   Stack trace:
   $0000000000000000
   $0000000000A08B7D line 1606 of ../designer/menueditor.pp
   $0000000000A0DD03 line 2578 of ../designer/menueditor.pp
   $00000000005B467A line 2242 of include/control.inc
   $00000000005B4B17 line 2375 of include/control.inc
   $0000000000434EF2 line 602 of ../inc/objpas.inc
   $00000000005B457F line 2202 of include/control.inc
   $00000000005A6FAD line 5396 of include/wincontrol.inc
   $000000000077B7A2 line 112 of lclmessageglue.pas
   $0000000000673075 line 3702 of gtk2proc.inc
   $00000000006826EA line 2137 of gtk2callback.inc
   $0000000000681D68 line 1899 of gtk2callback.inc
   $00007FCBE2536AFC