NM WiFi password dialog does not accept passwords and incorrect length

I discovered this issue on Solus Linux. Because Solus doesn't do any special things to the source, I decided to report this issue upstream. Probably other distros experience the same issue.

The problem: When entering only alphanumeric characters in the WiFi PSK password dialog, and maxing out the input to 60 characters, the input is accepted just fine. When mixing the 60 characters with any other normally accepted character, e.g. a space or backslash, the last character isn't accepted anymore and the connect button becomes greyed out. It does not matter, what position in the string is used by the non-alphanumerical character(s).

I suspect the input dialog to use multibyte UTF, and the length validation being counted in bytes (ASCII). A wild guess.

Another problem is that the dialog only accepts 59 or 60 characters, but 63 characters should be the correct limit for PSK.

I realize that, this issue will not generate problems for many users.......