Check email length in is_email()

[PranaliPatel]

In reference to this ticket - https://core.trac.wordpress.org/ticket/38506#comment:12

It would be better to check email length within the is_email() itself instead of
validating it at various other places.

[PranaliPatel]

Check email length ( to minimum of 5 )

[PranaliPatel]

As we are checking validation in is_email(), we can remove the string length check from the wp_handle_comment_submission().

[swissspidy]

#39136 was marked as a duplicate.

[milindmore22]

Removed email length check from rest-api as we are checking length in is_email() function already

[ashishtv]

Unit test

[swissspidy]

There should be a dedicated test for the new length test in is_email() (see Tests_Formatting_IsEmail), not just one handling comments. Also, since one patch changes code in the REST API, that part should get coverage as well.

[andraganescu]

Just re-adding the needs unit tests label back.

[donmhico]

I added a patch via GitHub PR but for some reason it's not showing here. ​https://github.com/WordPress/wordpress-develop/pull/413

Here's the patch - ​https://github.com/WordPress/wordpress-develop/pull/413.patch

I'll attach it as patch here as well.