Combining tilde passes `sanitize_title_with_dashes()` and so do most other diacritics

[anrghg]

Combining diacritics that are not acute, grave, hacek or macron (or the deprecated Vietnamese acute tone mark) are not removed by sanitize_title_with_dashes() removing characters individually and explicitly after URL-encoding.

If the goal is to remove accents, best would be removing the full class before URL-encoding:

$title = preg_replace( '/\p{M}/u', '', $title );

But isn’t remove_accents() called when removing diacritics?

So I’d suggest moving the combining diacritics part to remove_accents().

[anrghg]

Addenda

sanitize_title_with_dashes() also removes some format controls, some quotation marks and other punctuation, some modifier letters, and some symbols, among which the percent sign.

I think that here too, best is to do the full job by removing classes extensively before URL-encoding:

$title = preg_replace( '/[\p{Cf}\p{Ps}\p{Pe}\p{Pi}\p{Pf}\p{Po}\p{Sk}\p{So}\p{Lm}]/u', '', $title );

To avoid screwing up the percent sign removal, URL-decoding first seems to be the way to go. As by urldecode() the plus sign is converted to space, it could be maintained:

<?php
$title = str_replace( '%2B', '+', $title );
$title = urldecode( $title );

[costdev]

changes-requested refers to: "Feedback has been provided, and the attached patch needs to be updated." ​Reference.

I'm not sure if such a change would need a dev note, so I'll leave this to others to give their thoughts.

[anrghg]

Replying to costdev:

changes-requested refers to: "Feedback has been provided, and the attached patch needs to be updated." ​Reference.

I'm not sure if such a change would need a dev note, so I'll leave this to others to give their thoughts.

Sorry, indeed fixing a bug does not require any dev note, and as I’m to provide a patch, I’m removing all other keywords as well.