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Crashing in design mode after "Change Class" of a series

Original Reporter info from Mantis: wp @wpam
  • Reporter name:

Description:

TAChart crashes in design mode when the class type of a series is changed by selecting "Change Class" in the context menu

Steps to reproduce:

- Start a new project
- Add a TChart
- Add a series
- Right-click on the series in the object tree
- Select "Change Class..."
- Select any series type, e.g. TFuncSeries
--> after a few seconds Lazarus crashes with a message "Access violation"

Stack trace:

ChangePersistentClass-After--------------------------------------------
---ComponentIsInvisible: Adding Chart1LineSeries1:TBarSeries to InvisibleClasses.---
TApplication.HandleException: EAccessViolation
Access violation
  Stack trace:
  $007D7AAA  TDESIGNER__ADDUNDOACTION,  line 1875 of C:/Lazarus/lazarus-trunk_fpc-3.2.0/designer/designer.pp
  $007D5B0D  TDESIGNER__DOINSERTFROMSTREAM,  line 1379 of C:/Lazarus/lazarus-trunk_fpc-3.2.0/designer/designer.pp
  $007D53A1  TDESIGNER__INSERTFROMSTREAM,  line 1200 of C:/Lazarus/lazarus-trunk_fpc-3.2.0/designer/designer.pp
  $007E03CC  TCUSTOMFORMEDITOR__INSERTFROMSTREAM,  line 688 of customformeditor.pp
  $00C35D33  INSERTSTREAMEDSELECTION,  line 259 of C:/Lazarus/lazarus-trunk_fpc-3.2.0/designer/changeclassdialog.pas
  $00C35B03  CHANGEPERSISTENTCLASS,  line 291 of C:/Lazarus/lazarus-trunk_fpc-3.2.0/designer/changeclassdialog.pas
  $00C35901  SHOWCHANGECLASSDIALOG,  line 104 of C:/Lazarus/lazarus-trunk_fpc-3.2.0/designer/changeclassdialog.pas
  $007D7401  TDESIGNER__CHANGECLASS,  line 1739 of C:/Lazarus/lazarus-trunk_fpc-3.2.0/designer/designer.pp
  $0073E426  TOBJECTINSPECTORDLG__CHANGECLASSPOPUPMENUITEMCLICK,  line 5217 of objectinspector.pp
  $00598070  TMENUITEM__CLICK,  line 83 of ./include/menuitem.inc
  $0059874F  TMENUITEM__DOCLICKED,  line 296 of ./include/menuitem.inc
  $004105B1
  $0054BB51  WINDOWPROC,  line 2774 of ./win32/win32callback.inc
  $7755EF5B
  $77555ECA
  $77553C3A
  $77553A00

Additional information:

Was report in the forum thread about Laz 2.0.10 (https://forum.lazarus.freepascal.org/index.php/topic,50529.msg378861.html#msg378861),
Testing with Laz 1.8.4 shows the issue as well, it probably is existing all the time.

The same happens when an element of a TChartAxisTransformations component is made to change the class. The same with TChartToolset.

Since the lists in these components inherit from TIndexedComponentList it can be concluded that the issue probably is in the code this component or its componenteditor.

Mantis conversion info:

  • Mantis ID: 38375