4.4.0: new permalink editor brings confusion when editing Front Page

[lkraav]

Describe the bug
#11874 brought new sidebar permalink editor section.

This has usability problems when editing Front Page (and probably other special pages):

1. can't edit Page URL (can't tell you're supposed to be able to, until you edit some other non-special page)
2. editor should say something about why Page URL box is missing
3. clicking Title block only shows a huge unexpected button "Change Permalinks", with no edit control - I can't screenshot this, because the whole element disappears as soon as browser window loses focus for screenshot tools.

To Reproduce
Steps to reproduce the behavior:

1. Edit your assigned Front Page
2. Click on Title block
3. Unfold Permalinks document settings section

Expected behavior

• Page slug should be editable, no matter the configuration
• Special page assignment info should be display "This is your configured Front / Shop / Blog page"
• Avoid low use-case distraction of inviting people to system management Permalinks screen from an everyday use content editor screen

Screenshots

Desktop (please complete the following information):

• OS: Linux
• Browser Firefox
• Version 64beta

[swissspidy]

clicking Title block only shows a huge unexpected button "Change Permalinks", with no edit control - I can't screenshot this, because the whole element disappears as soon as browser window loses focus for screenshot tools.

#11970 has a screenshot.

This button should not be shown when editing the front page.

Page slug should be editable, no matter the configuration

There's no point in being able to change the slug when it has no effect. So some sort of help text would be more appropriate.

[lkraav]

There's no point in being able to change the slug when it has no effect. So some sort of help text would be more appropriate.

Front Page configuration may change over time, at which point an unoptimal slug might become a live one. I would let the user modify it and have a helpful, explanatory UI around it.

[designsimply]

Closing in favor of #12498 because it has a pull request associated.