Norihiro Tanaka wrote: > Hmm, how about the following test cases, although it is extreame? I don't think we need to worry about performance for the case when -w is given, and a pattern matches data that contains non-word characters. In practice, such cases are rare. I expect that most users would be surprised that -w can match non-word characters, and that users wouldn't object to -w rejecting such matches (if this wouldn't hurt performance significantly). While looking into this I did find a very small performance tweak for the test case, and installed the attached.