Bug 90528 Editor icon does not show problem decoration for second instance
3.1 M6 - open a .java file that has errors or warnings - the editor tab icon has the problem decoration - Window > New Window - open the same file in the new window - the editor tab icon is missing the problem decoration
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/javaeditor/CompilationUnitEditor.java
IDocument document= sourceViewer.getDocument();
			final Point selection= sourceViewer.getSelectedRange();
			final int offset= selection.x;
			final int length= selection.y;
			
			try {
				IRegion startLine= document.getLineInformationOfOffset(offset);
				IRegion endLine= document.getLineInformationOfOffset(offset + length);
				
				JavaHeuristicScanner scanner= new JavaHeuristicScanner(document);
				int nextToken= scanner.nextToken(offset + length, endLine.getOffset() + endLine.getLength());
				String next= nextToken == Symbols.TokenEOF ? null : document.get(offset, scanner.getPosition() - offset).trim();
				int prevToken= scanner.previousToken(offset - 1, startLine.getOffset());
				int prevTokenOffset= scanner.getPosition() + 1;
				String previous= prevToken == Symbols.TokenEOF ? null : document.get(prevTokenOffset, offset - prevTokenOffset).trim();
				
				switch (event.character) {
					case '(':
						if (!fCloseBrackets
								|| nextToken == Symbols.TokenLPAREN
								|| nextToken == Symbols.TokenIDENT 
								|| next != null && next.length() > 1)
							return;
						break;
						
					case '<':
						if (!(fCloseAngularBrackets && fCloseBrackets)
								|| nextToken == Symbols.TokenLESSTHAN 
								|| 		   prevToken != Symbols.TokenLBRACE	
										&& prevToken != Symbols.TokenRBRACE