Bug 40772 [plan item] Smart tab on empty lines
When having the caret on an empty line, pressing tab cleans up the line and sets the caret it the right indentation column.
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/preferences/WorkInProgressPreferencePage.java
gd= new GridData(GridData.FILL_HORIZONTAL);
		gd.horizontalAlignment= GridData.BEGINNING;
		gd.horizontalSpan= 2;
		fSetDefaultButton.setLayoutData(gd);
		
		fQuickDiffProviderList.addSelectionListener(new SelectionListener() {
			public void widgetDefaultSelected(SelectionEvent e) {
				
			}
			
			public void widgetSelected(SelectionEvent e) {
				handleProviderListSelection();
			}
		});
		
		fSetDefaultButton.addSelectionListener(new SelectionListener() {
			public void widgetDefaultSelected(SelectionEvent e) {
				
			}
			
			public void widgetSelected(SelectionEvent e) {
				int i= fQuickDiffProviderList.getSelectionIndex();
				for (int j= 0; j < fQuickDiffProviderListModel.length; j++) {
					if (getPreferenceStore().getString(ExtendedTextEditorPreferenceConstants.QUICK_DIFF_DEFAULT_PROVIDER).equals(fQuickDiffProviderListModel[j][0])) {
						fQuickDiffProviderList.remove(j);
						fQuickDiffProviderList.add(fQuickDiffProviderListModel[j][1], j);
					}
					if (i == j) {
						fQuickDiffProviderList.remove(j);
						fQuickDiffProviderList.add(fQuickDiffProviderListModel[j][1] + " " + PreferencesMessages.getString(PREFIX + "quickdiff.defaultlabel"), j);