[cdt-dev] Why does Property Page "apply" remove the configuration from M

[Jeff Johnston <jjohnstn@xxxxxxxxxx>]

I recently ran into a problem with the Autotools plugin and CDT 5.0.0.  
We have a class that inherits from AbstractCPropertyTab that adds an 
Autotools configure settings page as part of the C/C++ Build Settings.   
It has a canBeVisible method that calls a static method which checks if 
the project has an Autotools builder.

The code for that test used the IProject to get the ManagedBuildInfo 
which it then used to get the default configuration.  The 
ManagedBuildInfo.getDefaultConfiguration() method uses the internal 
managedMakeProject to get its configurations.  Well, for some reason, 
the Apply button ends up removing the configuration from the 
ManagedMakeProject.

If a change is made and the Apply button is pressed, everything works 
fine.  However, if the Ok button gets pressed after that, the 
canBeVisible() method gets called again for the sendOk and we are out of 
luck because there is no longer a default configuration.  I have since 
rewritten the code so that it now looks at the ProjectType id of the 
ManagedProject and that fixes this particular problem, but I do not 
understand why the configuration is being removed.

The following is the stack trace after hitting the apply button.  The 
configuration is removed which is why it is removed from the 
ManagedProject.  I don't understand why the performSave kicks this off 
since it can be just for an Apply.  Some further alterations might need 
to be performed on the configuration and there is also this dangling 
ManagedProject still in the ManagedBuildInfo that has no configuration.

Thread [main] (Suspended (breakpoint at line 336 in ManagedProject))   
   ManagedProject.removeConfiguration(String) line: 336   
   
ConfigurationDataProvider.removeConfiguration(ICConfigurationDescription, 
CConfigurationData, IProgressMonitor) line: 567   
   CProjectDescriptionManager.removeData(ICConfigurationDescription, 
CConfigurationData, IProgressMonitor) line: 1663   
   
CProjectDescriptionManager.checkRemovedConfigurations(ICDescriptionDelta) 
line: 2977   
   SetCProjectDescriptionOperation.executeOperation() line: 83   
   SetCProjectDescriptionOperation(CModelOperation).execute() line: 341   
   
SetCProjectDescriptionOperation(CModelOperation).run(IProgressMonitor) 
line: 606   
   Workspace.run(IWorkspaceRunnable, ISchedulingRule, int, 
IProgressMonitor) line: 1800   
   
SetCProjectDescriptionOperation(CModelOperation).runOperation(IProgressMonitor) 
line: 638   
   CProjectDescriptionManager.setProjectDescription(IProject, 
ICProjectDescription, int, IProgressMonitor) line: 1255   
   CProjectDescriptionManager.setProjectDescription(IProject, 
ICProjectDescription, boolean, IProgressMonitor) line: 1218   
   CProjectDescriptionManager.setProjectDescription(IProject, 
ICProjectDescription) line: 1211   
   CoreModel.setProjectDescription(IProject, ICProjectDescription) 
line: 1385   
   AbstractPage$5.run(IProgressMonitor) line: 570   
   WorkspaceModifyDelegatingOperation.execute(IProgressMonitor) line: 
69   
   WorkspaceModifyOperation$1.run(IProgressMonitor) line: 104   
   Workspace.run(IWorkspaceRunnable, ISchedulingRule, int, 
IProgressMonitor) line: 1800   
   
WorkspaceModifyDelegatingOperation(WorkspaceModifyOperation).run(IProgressMonitor) 
line: 116   
   ModalContext.runInCurrentThread(IRunnableWithProgress, 
IProgressMonitor) line: 446   
   ModalContext.run(IRunnableWithProgress, boolean, IProgressMonitor, 
Display) line: 354   
   ProgressMonitorDialog.run(boolean, boolean, IRunnableWithProgress) 
line: 507   
   Page_BuildSettings(AbstractPage).performSave(int) line: 581   
   Page_BuildSettings(AbstractPage).performApply() line: 436   
   PreferencePage$2.widgetSelected(SelectionEvent) line: 284   
   TypedListener.handleEvent(Event) line: 228   
   EventTable.sendEvent(Event) line: 84   
   Button(Widget).sendEvent(Event) line: 1158   
   Display.runDeferredEvents() line: 3401   
   Display.readAndDispatch() line: 3033   
   PropertyDialog(Window).runEventLoop(Shell) line: 825   
   PropertyDialog(Window).open() line: 801   
   PropertyDialogAction.run() line: 157   
   ProjectPropertyDialogAction.run() line: 77   
   ProjectPropertyDialogAction(Action).runWithEvent(Event) line: 498   
   ActionContributionItem.handleWidgetSelection(Event, boolean) line: 
583   
   ActionContributionItem.access$2(ActionContributionItem, Event, 
boolean) line: 500   
   ActionContributionItem$5.handleEvent(Event) line: 411   
   EventTable.sendEvent(Event) line: 84   
   MenuItem(Widget).sendEvent(Event) line: 1158   
   Display.runDeferredEvents() line: 3401   
   Display.readAndDispatch() line: 3033   
   Workbench.runEventLoop(Window$IExceptionHandler, Display) line: 2382   
   Workbench.runUI() line: 2346   
   Workbench.access$4(Workbench) line: 2198   
   Workbench$5.run() line: 493   
   Realm.runWithDefault(Realm, Runnable) line: 288   
   Workbench.createAndRunWorkbench(Display, WorkbenchAdvisor) line: 488   
   PlatformUI.createAndRunWorkbench(Display, WorkbenchAdvisor) line: 
149   
   IDEApplication.start(IApplicationContext) line: 113   
   EclipseAppHandle.run(Object) line: 193   
   EclipseAppLauncher.runApplication(Object) line: 110   
   EclipseAppLauncher.start(Object) line: 79   
   EclipseStarter.run(Object) line: 382   
   EclipseStarter.run(String[], Runnable) line: 179   
   NativeMethodAccessorImpl.invoke0(Method, Object, Object[]) line: not 
available [native method]   
   NativeMethodAccessorImpl.invoke(Object, Object[]) line: 57   
   DelegatingMethodAccessorImpl.invoke(Object, Object[]) line: 43   
   Method.invoke(Object, Object...) line: 616   
   Main.invokeFramework(String[], URL[]) line: 549   
   Main.basicRun(String[]) line: 504   
   Main.run(String[]) line: 1236   
   Main.main(String[]) line: 1212   

-- Jeff J.