Bug 21047 code formatter availability inconsistent
Sometimes the hotkey (ctrl-shift-f) and the menu entry for formatting the source code are disabled, while the entry in the context menu is enabled and works as expected. I didn't find any patterns on when this occurs till now.
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/javaeditor/CompilationUnitEditor.java
return false;
		try {
			return
				isBracket(document.getChar(offset - 1)) &&
				isBracket(document.getChar(offset));
			
		} catch (BadLocationException e) {
			return false;	
		}
	} 
	/**
	 * Jumps to the matching bracket.
	 */
	public void gotoMatchingBracket() {
		if (fBracketMatcher == null)
			fBracketMatcher= new JavaPairMatcher(BRACKETS);
		ISourceViewer sourceViewer= getSourceViewer();
		IDocument document= sourceViewer.getDocument();
		if (document == null)
			return;
		
		IRegion selection= getSignedSelection(sourceViewer);
		int selectionLength= Math.abs(selection.getLength());
		if (selectionLength > 1) {
			setStatusLineErrorMessage(JavaEditorMessages.getString("GotoMatchingBracket.error.invalidSelection"));			
			sourceViewer.getTextWidget().getDisplay().beep();
			return;
		}
		
		int sourceCaretOffset= selection.getOffset() + selection.getLength();