Bug 52346 [misc] Undo yields wrong code
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/javaeditor/CompilationUnitEditor.java
private int fTabRatio;
		private ILineTracker fLineTracker;
		
		public TabConverter() {
		} 
		
		public void setNumberOfSpacesPerTab(int ratio) {
			fTabRatio= ratio;
		}
		
		public void setLineTracker(ILineTracker lineTracker) {
			fLineTracker= lineTracker;
		}
		
		private int insertTabString(StringBuffer buffer, int offsetInLine) {