Wagtail 5.0 fixes

[katdom13]

Parent PR: #503

Supplementary fixes:

Snippet choosers with searchable snippets were displaying the search box, but not returning any results when the user enters a search query. This is due to a change in internal behaviour:

Wagtail 4.2 used to fall back to a partial_match search if there was no autocomplete option available in the Snippet's .search_fields

Wagtail 5.0 expects there to be an AutocompleteField

The release notes allude to it, but don't quite make this clear. The fix is to make sure that your Snippet has an AutocompleteField configured, e.g:

search_fields = [
    index.AutocompleteField("title"), (added line)
    index.SearchField("title"),
]

• Need to run update_index

[victoriachan]

Looks good!