Setting IDN domains for proxy servers leads to error in chrome and strange behaviour in firefox

[msva]

Hi there!
I've discovered, that if I set up HTTPS proxy with IDN domain name in unicode notation (that looks like シ.シ), proxying doesn't work as expected.

Chrome immediately fails with ERR_MANDATORY_PROXY_CONFIGURATION_FAILED error

Firefox, in order, just somewhy takes about 2 minutes to start loading the content (and after that it loads the page pretty fast).

In both cases, specifying proxy domain in ascii notation (xn--foo.xn-moo) makes it load in less than half a second.