arbitrary behavior for export package dialog

[gireeshpunathil]

steps to reproduce:

• create a plugin project
• open design editor
• select runtime and click add
• toggle the Show non-java packages a couple of times
• repeat this with selecting and deselecting items in the list
• watch the behavior of Add button

I see arbitrary behaviors for the Add button, w.r.t being enabled / disabled.

[vik-chand]

Nice catch! That's a bug. I can recreate it too

[gireeshpunathil]

relevant code:

eclipse.pde/ui/org.eclipse.pde.ui/src/org/eclipse/pde/internal/ui/editor/plugin/ExportPackageSection.java

Lines 383 to 434 in 91ab862

	private void handleAdd() {
	IPluginModelBase model = (IPluginModelBase) getPage().getModel();
	final IProject project = model.getUnderlyingResource().getProject();
	try {
	if (project.hasNature(JavaCore.NATURE_ID)) {
	ILabelProvider labelProvider = new JavaElementLabelProvider();
	final ConditionalListSelectionDialog dialog = new ConditionalListSelectionDialog(PDEPlugin.getActiveWorkbenchShell(), labelProvider, PDEUIMessages.ExportPackageSection_dialogButtonLabel);
	final Collection<String> pckgs = fHeader == null ? Collections.emptySet() : fHeader.getPackageNames();
	final boolean allowJava = "true".equals(getBundle().getHeader(ICoreConstants.ECLIPSE_JREBUNDLE)); //$NON-NLS-1$
	Runnable runnable = () -> {
	ArrayList<IPackageFragment> elements = new ArrayList<>();
	ArrayList<IPackageFragment> conditional = new ArrayList<>();
	IPackageFragment[] fragments = PDEJavaHelper.getPackageFragments(JavaCore.create(project), pckgs, allowJava);
	for (IPackageFragment fragment : fragments) {
	try {
	if (fragment.containsJavaResources()) {
	elements.add(fragment);
	} else {
	conditional.add(fragment);
	}
	} catch (JavaModelException e) {
	}
	}
	dialog.setElements(elements.toArray());
	dialog.setConditionalElements(conditional.toArray());
	dialog.setMultipleSelection(true);
	dialog.setMessage(PDEUIMessages.PackageSelectionDialog_label);
	dialog.setTitle(PDEUIMessages.ExportPackageSection_title);
	dialog.create();
	PlatformUI.getWorkbench().getHelpSystem().setHelp(dialog.getShell(), IHelpContextIds.EXPORT_PACKAGES);
	SWTUtil.setDialogSize(dialog, 400, 500);
	};
	BusyIndicator.showWhile(Display.getCurrent(), runnable);
	if (dialog.open() == Window.OK) {
	Object[] selected = dialog.getResult();
	if (fHeader != null) {
	for (Object selectedObject : selected) {
	IPackageFragment candidate = (IPackageFragment) selectedObject;
	fHeader.addPackage(new ExportPackageObject(fHeader, candidate, getVersionAttribute()));
	}
	} else {
	getBundle().setHeader(getExportedPackageHeader(), getValue(selected));
	// the way events get triggered, updateButtons isn't called
	if (selected.length > 0)
	getTablePart().setButtonEnabled(CALCULATE_USE_INDEX, true);
	}
	}
	labelProvider.dispose();
	}
	} catch (CoreException e) {
	}
	}

I am unable to locate the code pertinent to the button and its selection change callback, so not sure if this is an in-built behaviour of the ConditionalListSelectionDialog class or not.

[gireeshpunathil]

These are at least two threads that participate in this problem, so looks to me like a complex race condition.

FilteredList$TableUpdateJob.runInUIThread(IProgressMonitor) line: 543	
FilteredList$TableUpdateJob(UIJob).lambda$0(IProgressMonitor) line: 148	
0x000000080194e7a0.run() line: not available	
RunnableLock.run(Display) line: 40	
UISynchronizer(Synchronizer).runAsyncMessages(boolean) line: 132	
Display.runAsyncMessages(boolean) line: 4368	
Display.readAndDispatch() line: 3991	
ConditionalListSelectionDialog(Window).runEventLoop(Shell) line: 823	
ConditionalListSelectionDialog(Window).open() line: 799	
ConditionalListSelectionDialog(AbstractElementListSelectionDialog).open() line: 457	
ExportPackageSection.handleAdd() line: 418	

FilteredList.setElements(Object[]) line: 273	
ConditionalListSelectionDialog(AbstractElementListSelectionDialog).setListElements(Object[]) line: 191	
ConditionalListSelectionDialog(ElementListSelectionDialog).createDialogArea(Composite) line: 63	
ConditionalListSelectionDialog.createDialogArea(Composite) line: 43	
ConditionalListSelectionDialog(Dialog).createContents(Composite) line: 767	
ConditionalListSelectionDialog(Window).create() line: 431	
ConditionalListSelectionDialog(Dialog).create() line: 1094	
ConditionalListSelectionDialog(SelectionStatusDialog).create() line: 155	
ConditionalListSelectionDialog(AbstractElementListSelectionDialog).access$superCreate() line: 462	
ConditionalListSelectionDialog(AbstractElementListSelectionDialog).lambda$1() line: 469