Is this a bug? If I have:
Then select the first 'String' and press CtrlAltF7 (Highlight Usages), then the 'String' in 'StringBuffer' is also highlighted.
I hope this is a bug and not a feature, because it's useless if it's the latter. Highlight Usages gives a good overview of how a symbol participates in the logic of a class -- this 'highlight substring in file' behaviour loses this.
I can see how the behaviour as it stands might be useful, but 'Highlight Usages' was one of my favourite IDEA features. Is it gone for good? :(