Delphi 12 Athens: TJvTreeView fails with Access Violation after Windows RDP (mstsc.exe) remote session disconnect and connect again.

[alan008]

One form with TJvTreeView
Run application in remote session, close remote session window without closing the application, connect to remote session again. JvTreeView receives WM_NOTIFY (CN_NOTIFY) and Vcl.ComCtrls CNNotify procedure call fails with AV. Example project attached.
Problem not happen with Delphi's default TTreeView, so only TJvTreeView is affected.

JvTreeView_Delphi12_Test.zip

[alan008]

TJvCheckTreeView is also affected by this problem

[alan008]

Looks like JvExComCtrls is "somehow incompatible" with current Vcl.ComCtrls.pas implementation in Delphi 12.

[alan008]

Looks like same as #173

The stack trace is not very informative, because JvExComCtrls.pas (more exactly -JvExControls.macros) hacks current Delphi 12 implementation probably incorrectly.

[alan008]

Found simple way to reproduce this error without remote session, just enable visual styles and try to do TreeView.StyleName := 'Some Style'. Example attached, try to click Button1 at runtime

JvTreeView_Delphi12_Test.zip

[alan008]

Any news on this? At least reproducible?

[obones]

Any news on this? At least reproducible?

You do realize that we are a very small group of volunteers working on this project right?
We can only use our spare time for this and it has to be shared among many other things.

Having a test application helped quite a lot here, and as I suspected this has nothing to do with JvExComCtrls but all to do with a change inside TTreeNodes.ReadNodeData from the Delphi 12 VCL itself.

Anyway, a fix is already in the repository.

[alan008]

Great thanks!!! I'll test and write if it helps!
I'm working with Delphi since 2000s, and of couse I understand, that Delphi's community is still holding on individuals great personal effort (more often - voluntary). Anyway, bugs and compatibility with latest/future Delphi releases is a necessary requirement, because it allows to drive innovations in (a slightly vanishing) Delphi world. When large project migrates to new Delphi version, it's always a bit of pain, because (in this particular case), I cannot replace quickly TJvTreeView in 100+ forms into some other component.

[alan008]

Tested OK, the problem is solved! Thanks again!