Upgrade from book 2.0.x fails with TypeError type string on string in book_post_update_allowed_child_type_default6

Will take a look before 3.0.0 but this seems like it’s changing too much. Will take a different approach

Were you using a patch by chance?

I did a fresh install of 2.0.x
Configured the book settings to use Article and Basic page with Basic page as the child type
Switched to 3.0.x
Update hooks ran just fine
Config exported correctly.

Seems like it may have been a unique issue not sure how you ended up with allowed_type_book: 1

I can see the same thing happening on my site.

The error is happening because the `allowed_child_type_default6` hook happens before `convert_allowed_types_to_structured`, and the error is caused because `convert_allowed_types_to_structured` is changing the structure of the config that the `allowed_child_type_default6` hook is then updating.

The order makes sense because the post update hooks are executed alphabetically (see the api docs).

This section here:
"In contrast to hook_update_N() the alphanumeric naming of functions in the file is the only thing which ensures the execution order of those functions. If update order is mandatory, you should add numerical prefix to NAME or make it completely numerical."

It looks like someone has tried to set one of the hooks to fire last by adding the 6 to the end, but as the docs says the order should be determined by the prefix.

Since there is an order to the hooks in this file can I suggest changing the post update hook names to the following:

- book_post_update_convert_allowed_types_to_structured -> book_post_update_1convert_allowed_types_to_structured
- book_post_update_allowed_child_type_default6 -> book_post_update_6allowed_child_type_default

I'll create a PR with the change in now.

I was able to repro the error, not sure how I got there but my book.settings looked like

_core:
  default_config_hash: jmBcLtS4JshpXXtB9fsiBehhukIaDTQjvozHpbvVyPo
allowed_types:
  - book
book_sort: weight
use_parent_selector: false
use_alternative_form: false
child_type: book
truncate_label: true

the post update hook tries to update assuming there is an associative array for allowed_types

$allowed_types = $config->get('allowed_types');
  foreach ($allowed_types as &$type) {
    if (empty($type['child_type'])) {
      $type['child_type'] = $type['content_type'];
      $updated = TRUE;
    }
  }

However, as noted above, this is not always the case. Not sure why.

I am confused though about how @joseph.olstad ended up with those configs. I ran git grep -F "allowed_type_book" $(git rev-list --all) on 1.x 2.x and 3.x and couldn't find it anywhere so I don't think this will really work in that case.

I opened a new MR with my fix, but then I noticed a comment just now from @philipnorton42. That fix looks even better, I just tried it and it worked for me.

Thanks for the comment mdranove, appreciate you testing that so quickly :)

I've reverted the code on the branch that joseph created since I think it's detracting from the actual issue, where the hooks are just triggering out of order. I've updated the MR with the change to the hook names, which works when I've run some tests on it.

Thanks all!