Bug 40785 [plan item] Overview ruler improvements
- navigation from ruler to editor - hovering over header area shows number of errors/warning (header annotations in general)
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/javaeditor/CompilationUnitDocumentProvider.java
info.fCopy.reconcile();
			
			ICompilationUnit original= (ICompilationUnit) info.fCopy.getOriginalElement();
			IResource resource= original.getResource();
			
			if (resource == null) {
				
				super.doSaveDocument(monitor, element, document, overwrite);
				return;
			}
			
			if (resource != null && !overwrite)
				checkSynchronizationState(info.fModificationStamp, resource);
				
			if (fSavePolicy != null)
				fSavePolicy.preSave(info.fCopy);
			
			
			fireElementStateChanging(element);	
			try {
				
				fIsAboutToSave= true;
				
				
				if (JavaPlugin.USE_WORKING_COPY_OWNERS)
					info.fCopy.commitWorkingCopy(overwrite, monitor);
				else
					info.fCopy.commit(overwrite, monitor);