Deprioritizing new feature development on Partial Blocks in 2019 by the WMF's Anti-Harassment team but leaving open on the Blocking Tools backlog. After we measure the effectiveness of page and namespace Partial Blocks we will reassess additional time investment.

There should still be a way for a user blocked from creating pages to get from a redlink to search results for the redlinked title. Whether that is a link from a message saying something like "this page does not exist and you do not have permission to create it" or (maybe less preferably?) simply being taken to search results when clicking a red link or some other method I don't know.
The reason is that these search results can be good way to find the article one intended to link to when the error (e.g. misspelling) is not immediately obvious.

In T199918#6017396, @DannyS712 wrote:

@Niharika any objections from Anti-Harassment / is this approved from a product point of view?

@DannyS712 I think this task needs a bit more thinking about the planned work. I will discuss this with the team and we will decide whether it is worth investing time on this. I will ask you to look into something else if you are looking for something interesting to do. :)

Acceptance criteria

• On Special:Block, under 'Actions to block' add a checkbox for Creating pages
  • The checkbox should be unchecked by default
  • The checkbox should be marked as disabled unless the 'Partial' radio button is selected

I am wondering if the checkbox for Creating pages should be indented to be under the Partial blocks header to make it clear it's a partial block option.

• • If a user toggles either the 'Editing' checkbox or the Sitewide/Partial radio buttons, the checkbox should save whatever state the user configured it as. The state can be discarded on submit if the block is non-editing or sitewide.
• When a block is saved with the 'Creating pages' checkbox selected, the target user should not be able to create new pages in any namespace via API, via any tool in any editor, or via any Special page.
  • TBD: The 'Create' tab should not appear (sitewide blocked user still see the 'Create' tab.)

This makes sense.

• TBD: Clicking redlinks should not take the user to the edit mode (sitewide blocked users are still taken to edit mode)

Clicking redlinks should take them to the search with a message saying This page does not exist and you do not have the permission to create it. See more information. -- with a link to the block that blocked them from creating pages.

• When a Partial block is saved with the 'Creating pages' checkbox selected, the log items should indicate page creation is part of the block
• Special:BlockList should display that a user is blocked from creating pages as a bullet in the 'Block parameters' column
• TBD: When the 'Creating page' checkbox is selected, the 'Uploading files' checkbox should become selected and disabled. (Uploading a file creates the file page.)

This makes sense.

Perhaps page creation should be allowed as part of file uploading if T6995: Allow users to be blocked from uploading files only is also done?

• Blocked from page creation and file uploading: cannot creating file pages
• Blocked from page creation, not file uploading: can only create pages as part of file uploading

I added an investigation task in T252349: Investigation for blocking page creation with partial blocks to answer some open questions before we can work on this task.

Thanks @Aklapper!

Possible sub-task - use case for when:

User is blocked from EDITING a page
THEN
page is DELETED
User may now create/edit the page. So perhaps make the "edit block" become an edit OR create block (and not be dependent on the page title existing?)

@AGueyte I've updated the task description with a "What needs doing" section - it's actually a lot simpler than the Acceptance Criteria would suggest...

Change 683728 had a related patch set uploaded (by AGueyte; author: AGueyte):

[mediawiki/core@master] Block Creating page action

https://gerrit.wikimedia.org/r/683728

Change 683728 merged by jenkins-bot:

[mediawiki/core@master] Block Creating page action

https://gerrit.wikimedia.org/r/683728

When a user is blocked from creating new pages:

• They cannot create new pages via web or API (I tested several different namespaces and subpages)
  • This includes not being able to create their own User_talk page. I wonder if we should do the same thing for editing where they are allowed unless we explicitly say so.
• They can edit already existing pages
• They can move a page, even though I think technically this creates a new page (with the same name as the old page IIRC)
• They cannot upload a new file
• They can reupload an existing file
• They cannot successfully import (although they do not see a block error message)

I did some brief regression testing, checking that sitewide blocks prevented any page creation I tried (apart from user's own user_talk page) and partial blocks prevent creating in namespaces user is blocked from.

Test environment: https://en.wikipedia.beta.wmflabs.org (forgot to record the version)

Does this have to be enabled on a project-by-project basis? For example I see this exist at testwiki, but not test2wiki; and not at production projects like metawiki

It is currently only enabled on testwiki, cswiki, fawiki, and ptwiki. Full deployment is T280531.

@Xaosflux @JJMC89 we haven't heard any concerns from our pilot wikis and could consider a broader rollout if I can get community relations support to help with announcing these changes and making sure we spare some time to work on improvements needed, if any. Our team is focusing on IP Masking at the moment and I am not sure how quickly we will be able to do this. I will post any updates I have on the deployment task T280531.