String.to{Low,Upp}case() gives invalid result

[alexlamsl]

The following fails with node-chakracore@8.6.0:

// gives 304 instead
assert.strictEqual("İ".toLowerCase().charCodeAt(0), 105);
// gives 305 instead
assert.strictEqual("ı".toUpperCase().charCodeAt(0), 73);

Discovered in mishoo/UglifyJS#2886 (comment)

Other platforms are working as expected:

• IE 8~11
• FireFox 43
• Safari 5
• Opera 10
• Node 0.10~9

[MSLaguana]

Looks like we are also inconsistent between different OS: when I try your examples on Linux, the second case works correctly but the first does not. @jackhorton should we be using ICU for upper/lower casing?

[jackhorton]

Interesting. This is probably a Chakra bug, rather than a Node-ChakraCore bug, so I will make something to track this over there. With that being said, I dont think ICU should be required here, since the whole point of toLocale{Upper|Lower}Case is that they use locale-sensitive casing rules, so we are probably passing some bad flags to the Win32/POSIX APIs that handle the basic comparison.

[alexlamsl]

Still an issue as of v10.0.0

[jackhorton]

It should only be an issue on Windows. Can you confirm which platform you are running on?

[alexlamsl]

@jackhorton sorry for missing this detail in the original report – this is indeed tested on Windows 10 (x64).

[alexlamsl]

I can't confirm whether the issue exists on say Ubuntu, as mishoo/UglifyJS#3087 is blocked by #509, i.e. the process crashed before it can get to the test relevant to this report.

[alexlamsl]

Still an issue as of v10.1.0 (on Windows)

[alexlamsl]

Fixed in v10.6.0 - thanks!