user emails comparison should be case insensitive

[asaifm]

In user.php for WordPress 5.7, email update comparisons are case sensitive. Is there a specific reason for this? Because emails are case insensitive. Here is the line that does that:

if ( isset( $userdata['user_email'] ) && $user['user_email'] !== $userdata['user_email'] )

Can the function:

strcasecmp

be used instead? The problem is that there is a plugin that uses the function:

wp_update_user

And it would send a notification for email change even if it was the casing of the characters only.

Thanks for your time and consideration

[dd32]

Hi @asaifm and welcome to Trac!

Updating this to use lower-case comparisons (Just throw it through strtolower() IMHO) seems reasonable, however.. a plugin altering the user email address to lower case does seem unexpected and potentially a bigger bug than this is.

Just as a note, user@example.com and USER@example.com could technically be different users, as the email standard delegates that to the mail servers, however in reality no mail servers that I'm aware of have case sensitive handling..

[asaifm]

Hello @dd32,

Thanks for your response. The plugin that uses wp_update_user does not alter the casing. It simply passes the email address to it and does not perform any checks on the similarity of the old and new addresses.

Ok, I have seen your note in ​https://tools.ietf.org/html/rfc5321 now. I am not sure how to take this further, so feel free to close the ticket if you prefer to stick to the RFC.

[sabernhardt]

Related: #32158

strcasecmp was used for the wp_insert_user function (but not wp_update_user)