Moderated comments don't show blank links

[donncha]

Comments caught in moderation won't show the blank links inserted into them unless you edit them.

A comment with html code like <a href='​http://example.com/'></a> will not show that link on the moderation page.

[filosofo]

Maybe Slashdot-style show a URL's domain in parentheses?

blah blah blah (http://example.com) blah blah

[bumbu]

If the links are empty (or contain only blanks spaces, tabs...) then inside of them it is inserted a blank string

but it needs some performing because I don't know how to detect &nbsp;
also I am not sure if I gave right priority to new filter in add_filter function

[technosailor]

Refreshed, simplified and enhanced for 3.0

[technosailor]

Replaces empty, whitespace or nbsp anchor text with the sanitized URL. Improves regex to be less greedy for non href attributes

[nacin]

This isn't a regression, and looks like it could use some unit tests or at least some more testing. Moving to 3.1.

[shidouhikari]

I believe there are other special entities related to blank space too, like &emsp; &ensp; &thinsp;

I wasn't able to find now but I've already seen entities that generate different sized spaces, it had even a grath with sizes.

Using esc_url( $matches[2] ) instead of a simple "blank" is a great idea, it makes very explicit what's happening. Maybe wrap it in something like "original link had blank text so that link wasn't viewable, its attributes are:

|".

[chriscct7]

Looks good to go. Verified still a "bug", and patch looks good. Core devs might want to review intent

[stevegrunwell]

Refresh for WordPress 4.4 with addition of unit tests + better WordPress coding standards support

[stevegrunwell]

Added fresh version of the patch (hello 4 years ago!) with better support for the WordPress coding standards, actual unit tests, and a simplified regular expression for matching empty links.

[rachelbaker]

Duplicate of #36380.