win: perform case insensitive PATH= comparison

[cjihrig]

If I'm reading nodejs/node#20605 properly, then it seems that this comparison should be case insensitive. Untested locally, but that's what the CI is for.

[bzoz]

LGTM, CI: https://ci.nodejs.org/view/libuv/job/libuv-test-commit/830/

[bnoordhuis]

_wcsicmp() is affected by calls to setlocale(). I'd just write it out in full to avoid any confusion:

if ((env[0] == L'P' || env[0] == L'p') &&
    (env[1] == L'A' || env[1] == L'a') &&
    // etc

[JamesMGreene]

Thanks for the quick turnaround on getting this change underway, @cjihrig. 👍

[cjihrig]

Good enough CI with Ben's suggestion: https://ci.nodejs.org/view/libuv/job/libuv-test-commit/831/

[richardlau]

Should we note in the docs what happens on Windows when more than one variant of PATH is in options->env (e.g., PATH and Path)? make_program_env sorts, and this change will use the first variant found after sorting. It's an edge case, but is not hard to do in Node.js if you copy process.env and inadvertently set a different variant in the copy.

[cjihrig]

@richardlau would you be willing to open a docs PR? You seem to have a pretty good handle on what you'd like them to say.

[richardlau]

@richardlau would you be willing to open a docs PR? You seem to have a pretty good handle on what you'd like them to say.

Yes, but I'd like to convince myself first that the behaviour is actually desired. Copying from nodejs/node#20605 (comment):

This is kind of a note for myself since I haven't had time to look into this further, but thinking about this a bit more, I'm wondering if the libuv behaviour of using the passed in env.PATH (or env.Path after #1837) on Windows to find the command to execute is correct. I don't think the Unix platforms behave this way (need to check) and the passed in env is given to the child process but not used to execute the child process?