Access Violation at designtime when RootNodeCount is >0

[MikaelBox]

VT_fail.zip
Only one form with virtualtree. In design mode, IDE crashes on open this form or close this form. Access violation in module "borlndmm.dll".
RAD Studio 10.1 and VirtualTree 6.5.0 (older version crashes too (6.3.2))

[the-Arioch]

RAD Studio 10.1 had problems with FastMM i recall....
Maybe BorlandMM.dll just exposes the same Delphi bug.

pleriche/FastMM4#18

---

Anyway, BorlandMM.dll seems rather outdated aproach, why ever use it anyway ?

[MikaelBox]

FastMM is not installed.

[the-Arioch]

Does not matter, the bug is in Delphi RTL, and it might expose itself with any non-default, additional MM.
So, try to get rid of BorlndMM.dll

PS. BTW, buillt-in MM is also an older fork of FastMM,

[joachimmarder]

In my case the IDE crashes only when I close the form. This is the call stack:

[50039ED7]{borlndmm.dll} borlndmm.SysFreeMem (Line 2918, "GETMEM.INC" + 14) + $0
[5006896D]{rtl240.bpl  } System.UnicodeToUtf8 (Line 37472, "System.pas" + 19) + $16
[5016E982]{rtl240.bpl  } System.Classes.TComponent.Notification (Line 16004, "System.Classes.pas" + 8) + $1D
[50060744]{rtl240.bpl  } System.TMonitor.TryEnter (Line 18445, "System.pas" + 10) + $0
[50067FF6]{rtl240.bpl  } System.TInstBucket.RemoveInstItem (Line 36922, "System.pas" + 1) + $4
[50067528]{rtl240.bpl  } System.@IntfClear (Line 36349, "System.pas" + 10) + $0
[50063DA4]{rtl240.bpl  } System.@FinalizeArray (Line 31491, "System.pas" + 139) + $0
[50063C70]{rtl240.bpl  } System.@FinalizeRecord (Line 31198, "System.pas" + 25) + $0
[500601B8]{rtl240.bpl  } System.TMonitor.Destroy (Line 18078, "System.pas" + 0) + $0
[5005F839]{rtl240.bpl  } System.TObject.CleanupInstance (Line 16698, "System.pas" + 37) + $0
[5005A1A8]{rtl240.bpl  } System.@FreeMem (Line 4662, "System.pas" + 20) + $0
[50067528]{rtl240.bpl  } System.@IntfClear (Line 36349, "System.pas" + 10) + $0
[50063DA4]{rtl240.bpl  } System.@FinalizeArray (Line 31491, "System.pas" + 139) + $0
[50063C70]{rtl240.bpl  } System.@FinalizeRecord (Line 31198, "System.pas" + 25) + $0
[500601B8]{rtl240.bpl  } System.TMonitor.Destroy (Line 18078, "System.pas" + 0) + $0
[5005F839]{rtl240.bpl  } System.TObject.CleanupInstance (Line 16698, "System.pas" + 37) + $0
[5005A1A8]{rtl240.bpl  } System.@FreeMem (Line 4662, "System.pas" + 20) + $0
[5005F618]{rtl240.bpl  } System.TObject.FreeInstance (Line 16461, "System.pas" + 2) + $2
[5005FF0A]{rtl240.bpl  } System.@ClassDestroy (Line 17833, "System.pas" + 0) + $2
[5017B9B7]{rtl240.bpl  } System.Classes.{System.Generics.Collections}TList<System.Classes.TComponent>.Destroy (Line 4159, "System.Generics.Collections.pas" + 3) + $6
[5005F79C]{rtl240.bpl  } System.TObject.Free (Line 16529, "System.pas" + 1) + $4
[5016E905]{rtl240.bpl  } System.Classes.TComponent.RemoveNotification (Line 15983, "System.Classes.pas" + 13) + $15
[525BEF95]{vcldesigner240.bpl} VCLSurface.TVclDesignSurface.Destroy (Line 2917, "VCLSurface.pas" + 11) + $6
[5016E91E]{rtl240.bpl  } System.Classes.TComponent.RemoveFreeNotification (Line 15989, "System.Classes.pas" + 1) + $4
[525CD463]{vcldesigner240.bpl} VCLFormContainer.TEmbeddedFormHostWrapper.Destroy (Line 1844, "VCLFormContainer.pas" + 2) + $3
[5006876F]{rtl240.bpl  } System.TInterfacedObject._Release (Line 37333, "System.pas" + 7) + $7
[50067528]{rtl240.bpl  } System.@IntfClear (Line 36349, "System.pas" + 10) + $0
[525D0E6C]{vcldesigner240.bpl} VCLFormDesigner.TVCLRootDesigner.DeinitializeDesigner (Line 576, "VCLFormDesigner.pas" + 6) + $6
[21293357]{designide240.bpl} ComponentDesigner.TComponentRoot.InternalDeinitializeDesigner (Line 4973, "ComponentDesigner.pas" + 18) + $5
[21295FDD]{designide240.bpl} ComponentDesigner.TComponentRoot.Close (Line 5914, "ComponentDesigner.pas" + 5) + $5
[21F700A4]{delphicoreide240.bpl} DelphiModule.TPascalCodeMgrModHandler.Destroyed (Line 756, "DelphiModule.pas" + 11) + $5
[208EBF0D]{coreide240.bpl} DocModul.TCodeIDocModule.NotifyDestroyed (Line 2437, "DocModul.pas" + 1) + $8
[2126A039]{designide240.bpl} ToolUtils.ForEach (Line 99, "ToolUtils.pas" + 5) + $F
[208EBE7E]{coreide240.bpl} DocModul.TCodeIDocModule.NotifyDestruction (Line 2421, "DocModul.pas" + 1) + $3
[208E8E4C]{coreide240.bpl} DocModul.TDocModule.BeforeDestruction (Line 993, "DocModul.pas" + 12) + $2B
[5005FF69]{rtl240.bpl  } System.@BeforeDestruction (Line 17873, "System.pas" + 10) + $0
[20712232]{coreide240.bpl} SourceModule.TSourceModule.Create (Line 426, "SourceModule.pas" + 30) + $C4
[5005F79C]{rtl240.bpl  } System.TObject.Free (Line 16529, "System.pas" + 1) + $4
[208EA03A]{coreide240.bpl} DocModul.WalkDependencies (Line 1628, "DocModul.pas" + 7) + $E
[208EA085]{coreide240.bpl} DocModul.WalkDependencies (Line 1634, "DocModul.pas" + 13) + $E
[208E9177]{coreide240.bpl} DocModul.TDocModule.Close (Line 1107, "DocModul.pas" + 10) + $5
[208E9CEE]{coreide240.bpl} DocModul.TDocModule.SaveAndClose (Line 1467, "DocModul.pas" + 2) + $8
[208EB4D0]{coreide240.bpl} DocModul.TCodeIDocModule.GetViewCount (Line 2143, "DocModul.pas" + 0) + $0
[207DEF05]{coreide240.bpl} EditorBuffer.TEditBuffer.Save (Line 2728, "EditorBuffer.pas" + 2) + $7
[207E322F]{coreide240.bpl} EditorBuffer.TEditView.SaveAndClose (Line 5010, "EditorBuffer.pas" + 1) + $8
[20830BBC]{coreide240.bpl} EditorControl.TCustomEditControl.CloseView (Line 1926, "EditorControl.pas" + 8) + $5
[207E3E47]{coreide240.bpl} EditorBuffer.TEditView.TryCloseView (Line 5500, "EditorBuffer.pas" + 2) + $C
[2081FF87]{coreide240.bpl} EditorForm.TEditWindow.UpdateIncrSearchText (Line 4786, "EditorForm.pas" + 37) + $23
[50AA4097]{vcl240.bpl  } Vcl.Controls.TControl.Click (Line 7429, "Vcl.Controls.pas" + 9) + $8
[50C36358]{vcl240.bpl  } Vcl.Buttons.TSpeedButton.Click (Line 1550, "Vcl.Buttons.pas" + 0) + $0
[50C36342]{vcl240.bpl  } Vcl.Buttons.TSpeedButton.MouseUp (Line 1543, "Vcl.Buttons.pas" + 25) + $C
[50AA44D0]{vcl240.bpl  } Vcl.Controls.TControl.DoMouseUp (Line 7557, "Vcl.Controls.pas" + 2) + $28
[50AA4550]{vcl240.bpl  } Vcl.Controls.TControl.WMLButtonUp (Line 7570, "Vcl.Controls.pas" + 9) + $6
[50AA3B2A]{vcl240.bpl  } Vcl.Controls.TControl.WndProc (Line 7313, "Vcl.Controls.pas" + 91) + $6
[50AA3764]{vcl240.bpl  } Vcl.Controls.TControl.Perform (Line 7091, "Vcl.Controls.pas" + 10) + $8
[50AA7F20]{vcl240.bpl  } Vcl.Controls.TWinControl.IsControlMouseMsg (Line 9920, "Vcl.Controls.pas" + 15) + $29
[50AA84D6]{vcl240.bpl  } Vcl.Controls.TWinControl.WndProc (Line 10089, "Vcl.Controls.pas" + 104) + $6
[50AA7C94]{vcl240.bpl  } Vcl.Controls.TWinControl.MainWndProc (Line 9850, "Vcl.Controls.pas" + 3) + $6
[50170C64]{rtl240.bpl  } System.Classes.StdWndProc (Line 17178, "System.Classes.pas" + 8) + $0
[50063C70]{rtl240.bpl  } System.@FinalizeRecord (Line 31198, "System.pas" + 25) + $0
[50063DA4]{rtl240.bpl  } System.@FinalizeArray (Line 31491, "System.pas" + 139) + $0
[50063C70]{rtl240.bpl  } System.@FinalizeRecord (Line 31198, "System.pas" + 25) + $0
[50BEFFDD]{vcl240.bpl  } Vcl.Forms.TApplication.CancelHint (Line 11363, "Vcl.Forms.pas" + 6) + $D
[50BEEC6F]{vcl240.bpl  } Vcl.Forms.TApplication.ProcessMessage (Line 10534, "Vcl.Forms.pas" + 23) + $1
[50BEECB2]{vcl240.bpl  } Vcl.Forms.TApplication.HandleMessage (Line 10564, "Vcl.Forms.pas" + 1) + $4
[50BEEFE5]{vcl240.bpl  } Vcl.Forms.TApplication.Run (Line 10702, "Vcl.Forms.pas" + 26) + $3

It however does not contain any Virtual TreeView code. Is your call stack similar?

[joachimmarder]

So, try to get rid of BorlndMM.dll

@the-Arioch: I don't think BorlandMM.dll is actively used by the sample or Virtual TreeView, but only by RAD Studio.

[joachimmarder]

I added a minmized version of the project:
Minimal.zip

It seems that this is sufficient to provoke the AV:

  object vstCalendar: TVirtualStringTree
    NodeDataSize = 4
    RootNodeCount = 7
  end

Setting NodeDataSize to its default value 0 prevents the AV.

[joachimmarder]

Reopening issue because this fix causes some projects to fail at runtime if their form was opened in the IDE. Example: GeneralAbilities.dfm in Advanced.dproj.

Reason: A NodeDataSize of 4 instead of no value is written to the DFM, which prevents ValidateNodeDataSize() to be called.

[the-Arioch]

Hmmm.... indeed. Merely opening your MINIMAL project in my XE2 and then closing it WITHOUT SAVE kills my IDE - it gets into invinite AV loop within vcl160bpl

So your fixe basically moved IDE crash from "on open" to "on close" :-)

i meant previous, 4bd18a2 commit

[joachimmarder]

So your fixe basically moved IDE crash from "on open" to "on close" :-)

At least not in 10.1 Berlin, the AV disappeared reliably here.