Markdown's URL parsing does not properly handle unicode

At some point in the past, unicode symbols such as Japanese kana became supported in Stack Exchange question URLs.

However, in comments and posts, when pasting a link using these symbols, they are truncated. For example, the following URL:

https://japanese.stackexchange.com/questions/2102/what-is-the-こと-in-sentences-suc‌​h-as-あなたのことが好きだ

... is the correct URL for the question with ID 2102. However, the following code does not create a link:

[Link title](https://japanese.stackexchange.com/questions/2102/what-is-the-こと-in-sentences-suc‌​h-as-あなたのことが好きだ)

... and, if you just paste the link itself without the []() Markdown, you get this (hover over it to see the actual link URL):

What is the こと in sentences such as あなたのことが好きだ?‌​h-as-あなたのことが好きだ

... which produces the following (in case this post fixes itself):

Can we get link parsing support for these unicode characters in Markdown []() and auto-linking syntax?