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/javaeditor/CompilationUnitEditor.java
if (provider.isDeleted(input) && original != null) {
			String message= JavaEditorMessages.getFormattedString("CompilationUnitEditor.warning.save.delete", new Object[] { original.getName() }); 
			dialog.setErrorMessage(null);
			dialog.setMessage(message, IMessageProvider.WARNING);
		}
			
		if (dialog.open() == Window.CANCEL) {
			if (progressMonitor != null)
				progressMonitor.setCanceled(true);
			return;
		}
			
		IPath filePath= dialog.getResult();
		if (filePath == null) {
			if (progressMonitor != null)
				progressMonitor.setCanceled(true);
			return;
		}
			
		IWorkspace workspace= ResourcesPlugin.getWorkspace();
		IFile file= workspace.getRoot().getFile(filePath);
		final IEditorInput newInput= new FileEditorInput(file);
		
		WorkspaceModifyOperation op= new WorkspaceModifyOperation() {
			public void execute(final IProgressMonitor monitor) throws CoreException {
				getDocumentProvider().saveDocument(monitor, newInput, getDocumentProvider().getDocument(getEditorInput()), true);
			}
		};
		
		boolean success= false;