Indirect modification of overloaded element with Views responsive table

Rerolled for 10.1.

Rerolled this patch https://www.drupal.org/project/drupal/issues/2894449#comment-12803095 🐛 Indirect modification of overloaded element with Views responsive table Fixed against 10.1.x branch.

Tried to fix the failures in #36.
Please review.

Patch still applies to 11.x but I think we need more detailed steps to reproduce in the IS.

IS talks about priorities when the comments talk about merging fields?

Here's a view that has the problem. Here's how it was created:

1. Install the standard profile
2. Create a single article node for some test content
3. Create a view on nodes, using the table display and a page display
4. Add title, content type and published fields
5. Use the table settings to set the responsive priority to high, high, low for the columns and then press apply
6. Go back to the table settings and set the column for the "content type" field to "published" and press apply
7. Check the log for notices

Here's an additional test that proves the fix. And a patch merging the fix and test...

Given that this code is already producing attribute objects in the preprocess function - we just making them a little earlier - I don't think there are any tricky BC implications for this fix.

The last submitted patch, 40: 2894449-40.test-only.patch, failed testing. View results →

Using view provided by @alexpott in #39 showed the error.
Also the test-only patch in #40

Looking at the fix in #40 it matches the IS and didn't cause any failures. Think this is good.

Committed/pushed to 11.x and cherry-picked to 10.1.x, thanks!

Automatically closed - issue fixed for 2 weeks with no activity.