It seems the inner literal detector fails spectacularly in cases of
concatenations that involve groups. The issue here is that if the prefix
of a group inside a concatenation can match the empty string, then any
literals generated to that point in the concatenation need to be cut
such that they are never extended. The detector isn't really built to
handle this case, so we just act conservative cut literals whenever we
see a sub-group. This may make some regexes slower, but the inner
literal detector already misses plenty of cases.
Literal detection (including in the regex engine) is a key component
that needs to be completely rethought at some point.
Fixes#1064
This basically rewrites every integration test. We reduce the amount of
magic involved here in terms of which arguments are being passed to
ripgrep processes. To make up for the boiler plate saved by the magic,
we make the Dir (formerly WorkDir) type a bit nicer to use, along with a
new TestCommand that wraps a std::process::Command. In exchange, we get
tests that are easier to read and write.
We also run every test with the `--pcre2` flag to make sure that works,
when PCRE2 is available.
