Input a string with several continuous no-break spaces (Alt+0160 on Windows). Like this one (do not copy and paste) :

aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa        .

After submission the bug makes the string change to :

aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa .

You can resize your browser window to check no-break and breakable spaces. Especially check the dot character at the end of the 'a' sequence.

The result will be displayed above :