8384082: Incorrect surrogate handling in Pattern.hasBaseCharacter for word boundaries

[cushon]

Please consider this fix to the handling of word boundaries (\b) with non-spacing marks with non-BMP base characters, when UNICODE_CHARACTER_CLASS is not set.

See discussion in JDK-8384082.

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Issue

• JDK-8384082: Incorrect surrogate handling in Pattern.hasBaseCharacter for word boundaries (Bug - P4)

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[mlbridge]

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• 00: Full (e0e85660)

[AlanBateman]

The change means that boundary offsets will change for existing (but maybe buggy) code that uses \b. So I think we need to think about the compatibility impact and get some sense as to whether this could cause problems with existing code.

[cushon]

The change means that boundary offsets will change for existing (but maybe buggy) code that uses \b. So I think we need to think about the compatibility impact and get some sense as to whether this could cause problems with existing code.

I can do more corpus analysis of existing code.

I found this by fuzzing, I haven't seen any occurrences of it with real-world regexes yet. I suspect the compatibility impact is minimal.

[AlanBateman]

I can do more corpus analysis of existing code.

I found this by fuzzing, I haven't seen any occurrences of it with real-world regexes yet. I suspect the compatibility impact is minimal.

Thanks. I just have a concern that there may be simple tokenizers or parsers using \b.