Do not use ZWNJ and ZWJ in post name (slug and url)

[behzadian]

If I use Zero Width Non Joiner char in post title (and post title will be used for post slug and name as default), url will be ugly.
ZWNJ is a character used to split two words without real space, for example I in work (پیامک‌ها) there is a ZWNJ between (پیامک) and (ها). If I remove ZWNJ, it will be "پیامکها" which is wrong in Persian (and similar languages). Now if I use ZWNJ in slug, makes url so ugly, for example "/پیامک%e2%80%8cها/".
I changed function remove_accents( $string ) and add two replacement as below:
`
Grave accent.
'Ǜ' => 'U',
'ǜ' => 'u',
Persian.
'‌' => '-', added
'‍' => '-', added
`
to replace these chars to space

I do not know if it is right place or wrong, but I added two lines to remove ZWNJ and ZWJ from url.
Right? because it works
Wrong? because Persian a language not an accent!
I'm not Wordpress developer, so I don't know where to add codes
I created a ticket and explained what I done here (https://core.trac.wordpress.org/ticket/50924)

Trac ticket:

[johnbillion]

Welcome @behzadian. Thanks for the ticket and the PR!

This would be better done by using the hexadecimal representation of the Unicode codepoint instead of the actual character in each array key, so it's visible to readers of the code.

I think these are correct but I've not done any testing at all:

• "\xe2\x80\x8c"
• "\xe2\x80\x8d"

[SergeyBiryukov]

Related: #44958, #47594, #47912.

[hellofromTonya]

Per Sergey during today's scrub:

Will try to address before beta, or punt otherwise.

[Mista-Flo]

Added some unit tests + farsi pack for tests

[Mista-Flo]

Hi there,

I tried to drop a new patch for this issue.

The thing is, I had to add the persian translation in the test suite in order to properly switch to fa_IR locale. After that the RTL was ok and I could test.

That said, I tried to implement both @behzadian and @johnbillion suggestion, I'm not sure about the last one, but the unit tests work.

[Mista-Flo]

Fix huge po/mo file

[SergeyBiryukov]

Didn't get a chance to review this in time for 5.6 Beta 1, moving to the next release for now.

[hellofromTonya]

Scheduling this ticket for Testing Scrub, but need more information for the testers to QA it:

• What are the steps to reproduce the problem?
• Are there any testing dependencies such as a plugin or script?
• What is the expected behavior after applying the patch?

[lukecarbis]

Shifting this to 5.8, since 5.7 beta 3 has a soft string freeze.

[dariak]

QA feedback: in order we test the fix correctly, we would like to clarify the expected results.
To reproduce the bug:

1. Start creating new post.
2. Enter the following title "پیامک‌ها"
3. Publish your post and check the slug, it is "پیامک%e2%80%8cها/"

Is this correct? This is current behaviour on 5.7.2 version.

To test the fix:

1. Start creating new post.
2. Enter the following title "پیامک‌ها"
3. Publish your post and check the slug.

What is exactly expected to see in the slug?

[audrasjb]

The provided patch still needs some testing.
Given we're about to release 5.8 beta 1, let's move it for 5.9 consideration.

[audrasjb]

As per today's bug scrub, let's move this ticket to Future release pending testing info/feedback.

[SergeyBiryukov]

Thanks everyone! This appears to be resolved as part of [51984] / #47912.