Bug 63898 [reconciling] Multiple threads calling IJavaReconcilingListener#reconciled() at the same time
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/javaeditor/CompilationUnitEditor.java
String text= command.text;
			if (text == null)
				return;
				
			int index= text.indexOf('\t');
			if (index > -1) {
				
				StringBuffer buffer= new StringBuffer();
				
				fLineTracker.set(command.text);
				int lines= fLineTracker.getNumberOfLines();
				
				try {
						
						for (int i= 0; i < lines; i++) {
							
							int offset= fLineTracker.getLineOffset(i);
							int endOffset= offset + fLineTracker.getLineLength(i);
							String line= text.substring(offset, endOffset);
							
							int position= 0;
							if (i == 0) {
								IRegion firstLine= document.getLineInformationOfOffset(command.offset);
								position= command.offset - firstLine.getOffset();	
							}
							
							int length= line.length();
							for (int j= 0; j < length; j++) {
								char c= line.charAt(j);
								if (c == '\t') {