chrono-tz doesn't build anymore with latest regex-syntax

[meh]

Sorry for finding these issues in small steps instead of all at once, one of the regular expressions in chrono-tz is not parsing anymore, which makes the build script fail.

The regular expression comes from here, an issue about it was opened here.

Would this be considered a breaking change since it was working before?

[BurntSushi]

Yes, it's a bug, and not surprising sadly :-(. I was somewhat expecting bugs in the case insensitive mode. I wrote as many tests as I could think of, but it looks like some cases have eluded me! I will try to get a fix out today.

[BurntSushi]

OK, I've reproduced this down to a minimal example:

(?x)[ / - ]

which produces

regex parse error:
    (?x)[ / - ]
        ^^
error: unclosed character class

Another variant:

(?x)[ a - ]

which produces

regex parse error:
    (?x)[ a - ]
          ^^^^^
error: invalid character class range, the start must be <= the end

In other words, the parser is treating the trailing - as if it signified a range, but it should actually treat the regexes as equivalent to [/-] (or [a-]), which is a special case of character class syntax where the trailing - is treated as a literal - instead of a marker for a range. We get [/-] right, but not (?x)[ / - ] right, presumably because the check for the trailing - is not accounting for whitespace insensitive mode.

This should be straight-forward to fix.

[meh]

Nice, I'm going to add [patch.crates-io] for regex-syntax when it's fixed so I can see if there's anything else that affects me before I make you go through the release churn again 🐼

[BurntSushi]

Thanks! <3 :)

[BurntSushi]

OK, I've pushed a fix. I did try running your chrono-tz tests and everything seemed to work. If you have other crates with lots of regexes, it would be much appreciated to test those too if possible! :-)

[meh]

Everything is building and all tests are green here.

Thanks!

[BurntSushi]

@meh regex-syntax 0.5.2 is now on crates.io with this fix. I don't believe a new regex release is required. (Come to think of it, the previous release of regex wasn't required either, although I did that to bring in the nest_limit API.)

[meh]

Everything seems to be still fine, so thanks a bunch 🐼