Bug 330553 [Import/Export] Importing a project that exists in workspace location merges the contents
(1) Create a project in the default location (2) Export it to an archive (3) Delete it (but don't choose the option to delete from disk) (4) Make some changes in the <workspace root>/<project> directory (4) Import the archive you exported in step 2 This results in files from both the archive and directory. If the directory already has a file thats available in the archive, then it doesn't modify it. Ideally we shouldn't be allowing the import at all.
bundles/org.eclipse.ui.ide/src/org/eclipse/ui/internal/wizards/datatransfer/WizardProjectsImportPage.java
Button selectAll = new Button(buttonsComposite, SWT.PUSH);
		selectAll.setText(DataTransferMessages.DataTransfer_selectAll);
		selectAll.addSelectionListener(new SelectionAdapter() {
			public void widgetSelected(SelectionEvent e) {
				for (int i = 0; i < selectedProjects.length; i++) {
					if(selectedProjects[i].hasConflicts)
						projectsList.setChecked(selectedProjects[i], false);
					else
						projectsList.setChecked(selectedProjects[i], true);
				}
				setPageComplete(projectsList.getCheckedElements().length > 0);
			}
		});
		Dialog.applyDialogFont(selectAll);
		setButtonLayoutData(selectAll);
		Button deselectAll = new Button(buttonsComposite, SWT.PUSH);
		deselectAll.setText(DataTransferMessages.DataTransfer_deselectAll);
		deselectAll.addSelectionListener(new SelectionAdapter() {
			/*
			 * (non-Javadoc)
			 * 
			 * @see
			 * org.eclipse.swt.events.SelectionAdapter#widgetSelected(org.eclipse
			 * .swt.events.SelectionEvent)
			 */
			public void widgetSelected(SelectionEvent e) {
				projectsList.setCheckedElements(new Object[0]);
				setPageComplete(false);
			}
		});