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
return;
					if (hasIdentifierToTheLeft(document, offset) || hasIdentifierToTheRight(document, offset + length))
						return;
				}
				
				
			case '"':
				if (event.character == '"') {
					if (!fCloseStrings)
						return;
					if (hasIdentifierToTheLeft(document, offset) || hasIdentifierToTheRight(document, offset + length))
						return;
				}
				
				try {		
					ITypedRegion partition= TextUtilities.getPartition(document, IJavaPartitions.JAVA_PARTITIONING, offset);
					if (! IDocument.DEFAULT_CONTENT_TYPE.equals(partition.getType()) && partition.getOffset() != offset)
						return;
						
					if (!validateEditorInputState())
						return;
					final char character= event.character;
					final char closingCharacter= getPeerCharacter(character);
					final StringBuffer buffer= new StringBuffer();
					buffer.append(character);
					buffer.append(closingCharacter);
					document.replace(offset, length, buffer.toString());
					
					
					BracketLevel level= new BracketLevel();