Crash when sending copy operation to background

[Flint]

Code: Select all

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Total Commander 8.01
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Access violation.
Access violation
Windows 7 SP1 6.1 (Build 7601)

Please report this error to the Author, with a description
of what you were doing when this error occurred!

Stack trace (x64):40F30C
40EB72 7EE8B7 894AE3 77309BD1 43F4E3 43F971 71F0DC 43F917
404B2C 
Press Ctrl+C to copy this report!
Continue execution?
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Да   Нет   
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I started to copy contents of a directory to another directory. When I pressed the "Background" button in the progress dialog, I got the quoted crash message.

OS: Win7 SP1 x64
TC 8.01 x64

[ghisler(Author)]

Thanks for your report - unfortunately the error is not in TC. Here is the analyzed stack trace:

Code: Select all

Stack trace
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  $000000000040F30C
  $000000000040EB72
  $00000000007EE8B7  WINDOWPROC,  line 2396 of ./win32/win32callback.inc
  if (PLMsg = @LMMouse) and not (lWinControl is TScrollingWinControl) then

  $0000000000894AE3  BUTTONWNDPROC,  line 1643 of ./win32/win32wsstdctrls.pp
  $0000000077309BD1
  $000000000043F4E3  TAPPLICATION__HANDLEMESSAGE,  line 1280 of ./include/application.inc
  $000000000043F971  TAPPLICATION__RUNLOOP,  line 1413 of ./include/application.inc
  $000000000071F0DC  TWIDGETSET__APPRUN,  line 60 of ./include/interfacebase.inc
  $000000000043F917  TAPPLICATION__RUN,  line 1401 of ./include/application.inc
  $0000000000404B2C  main,  line 401 of TOTALCMD.lpr
  $000000000000000A
  $0000000000002002

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OK   
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It looks like you have installed a tool which adds its own controls to other program's dialog boxes or title bars. The Lazarus code tries to dispatch a message to such an element, but fails.

[Flint]

Hm… No, I don't have additional controls in window titles or dialogs.

I do use some hooker tools though, like PowerPro which intercept some keyboard and mouse events. Could such tool be a source of this crash?

And another idea: I remember that when I pressed the Background button, the copying was almost finished already. Could it be that a race condition occurred, like following?
1) I press the button;
2) immediately after this, the copying procedure finishes;
3) TC destroys the dialog;
4) and only now TC tries to process and dispatch the button message — but the button is already gone with the dialog, nowhere to dispatch, hence the crash.

[ghisler(Author)]

I do use some hooker tools though, like PowerPro which intercept some keyboard and mouse events. Could such tool be a source of this crash?

Yes, could be - how easy can you reproduce the error? Can you try to reproduce it with PowerPro disabled?

I don't think that it's a race condition, but I will check it.

[Flint]

Can you try to reproduce it with PowerPro disabled?

I tried to reproduce it, but failed, even with PowerPro running, so it's hard to tell. I cannot know for sure, of course, but still I doubt that PowerPro could lead to such a problem. It does not modify controls in windows on its own accord (at least, I didn't detect any such behavior during several years of using this tool), and I have configured no rules or plugins which could affect any button in any way.

I don't think that it's a race condition, but I will check it.

OK, thank you.