Three new checks are now applied to user signatures in preferences:
* Disallow invalid HTML and lint errors (T140606)
Since 15e0e9bb4b we can rely on Parsoid to check the signature for
lint errors. (The old PHP Parser doesn't have this capability.)
Most importantly, this will disallow unclosed HTML tags. Unclosed
formatting tags like `<i>` (and also wikitext markup like `''`)
could affect the entire page with the bad markup.
New configuration variable $wgSignatureAllowedLintErrors is added
to allow ignoring some errors. The default value ignores the
'obsolete-tag' error (caused by HTML tags like `<font>` and `<tt>`.)
* Require a link to user page, talk page or contributions (T237700)
Various tools don't work correctly when such a link is missing. For
example, Echo notifications are not sent, DiscussionTools will not
allow replying to these comments, English Wikipedia's SineBot treats
these comments as unsigned.
Such requirement has been present for a long time in many Wikimedia
wikis' policies, but it was not enforced by software.
* Disallow "nested" substitution in signature (T230652)
Clever abuse of "subst" markup and tildes allows users to save edits
containing wikitext in which substitution occurs again when the page
is next saved. Disallow this in signatures, at least.
New configuration variable $wgSignatureValidation is added to control
what we do about the result of the validation described above. The
options are:
* 'warning':
Only displays a warning near the field on Special:Preferences if
the current signature is invalid. Signatures can still be changed
regardless of validity and will be used when signing comments.
* 'new':
In addition to the above, if a user tries to change their signature,
the new one must be valid. Existing invalid signatures are still
used when signing comments.
* 'disallow':
In addition to the above, existing invalid signatures are no longer
used when signing comments.
Bug: T140606
Bug: T237700
Bug: T230652
Change-Id: I07c575c2d9d2afe7a89c4847d16ac044417297bf
df7231ad89