irregex chunked matching breaks when using positive lookbehind with submatches

[sjamaan]

When using a custom, non-trivial chunker (ie, not the shipped string chunker), submatches in (positive) lookbehind patterns will be returned as string-chunker type chunks. This breaks the expectation of returning a chunk in our own custom type like we get with any other submatch.

This has been reported to Alex, and is included in the upstream test suite as a breaking test. Too complicated to make a simple test script for CHICKEN, but when fixed should be backported.

For now I hope we can get this into 4.9.0, but it may need to be postponed.

[sjamaan]

Making it minor, as not many people will be using the chunking API (and of those few people, using positive lookbehind with submatches).

[sjamaan]

Fixed by 6ca60446ca6044