In multisite e-mails can contain HTML entities

[stephenharris]

This ticket concerns e-mails which are sent in a multsite context when a blog's admin e-mail is changed, or a user changes their e-mail address.

If the sitename contains HTML entities these appear in the e-mail - they are not decoded.

If the blogname contains quotes these appear in the e-mail as HTML entities. ([27801] decoded all but the quotes).

This bug was fixed for non-multsite installations in #9913. Also related: #35415 and #12584

[stephenharris]

Decode HTML entities in site name and blog name for MS emails

[stephenharris]

Patch contains tests for bug. I've also included a couple of other tests relating to the two functions fixed, although not related to this ticket.

[swissspidy]

See also #39446, #35283.

[swissspidy]

In 40632:

Mail: Ensure entities are decoded in email change notifications on Multisite.

Adds new tests to ensure this bug does not pop up again.

Props stephenharris.
Fixes #40015.

[johnbillion]

In 41165:

Users: Re-add entity decoding to the site name before it's used in the email address change confirmation email.

This was accidentally removed in [41163].

See #40015, #16470

[johnbillion]

In 41170:

Users: Update some tests for admin email change confirmation emails after [41164].

See #40015, #39117

[johnbillion]

In 41171:

Users: Further fixes to entitiy decoding in the user email address change confirmation email, and the corresponding tests.

See #16470, #40015