The Link Checker tool does not detect some links

[Djibs13]

hello,

The Link Checker tool in WordPress 4.6 doesn’t detect an error when you put something before ‘http(s)‘. Example: xhttps://www.google.com

And the tool does not detect error if a missing letter in "http".
examples :
ttps://core.trac.wordpress.org/newticket
htps://core.trac.wordpress.org/newticket
htts://core.trac.wordpress.org/newticket

[Presskopp]

Confirmed. You can enter most kinds of stupidity and it will not fire.

Related: #36638, code to find in [38159]

@azaozz

[azaozz]

Right. In order to not flag all the various ​URI schemes, it only checks links that start with http. Note that there is another small piece of regex in both link dialogs that prepends http:// to URIs that do not look like local.

On the other hand this can be changed to trigger on anything other than /^(https?|ftp|mailto):|^\//i as these uncommon schemes are probably used very very rarely.

[Presskopp]

related: #32816

Fixes to the link validation in the TinyMCE editor.

The Link Checker tool in did not correctly validate the Protocol in the links, allowing anything to be written before the ":" part of the link without displaying it as invalid (e.g. _qwerty://www.google.com_).

The validation should now mark as invalid anything that is not a _http(s):_, _mailto:_ or _​ftp://_ link.

Trac ticket: https://core.trac.wordpress.org/ticket/37758

[aleksganev]

Hey guys, this is my first patch, so I hope I did everything correctly.

I used @azaozz's suggestion and made the validation mark as invalid everything except http(s), mailto and ftp links. I reused the email check which was already in the file, added a new test that checks for "ftp:" in the beginning of the link and modified the link check, so that it allows only valid http and https urls. If all 3 of the tests fail, the string will be marked as invalid.

PR Looks fine.
the line -
if ( ! isLink && ! isEmail && ! isFtp )

is more readable if written this way

if ( ! ( isLink || isEmail || isFtp ) )

@atiqsu Updated that line as suggested. Please take another look.
Commit - ​2ae8cf8