r87339 is marked as TODO, but just to have a bug for it: 100 characters are really short, especially when you want to enter an URL to document deletions due to copyright violations.
I used Web Developer to disable the maxlength and succeeded to put in approximately 250 bytes (as expected), so the length should increase.
Version: 1.19
Severity: enhancement
See Also:
https://bugzilla.wikimedia.org/show_bug.cgi?id=28694