`get_terms()` with `all_with_object_id` returns cached `stdClass` objects

[dlh]

Two identical calls to get_terms() with 'fields' => 'all_with_object_id' will return an array of WP_Term objects for the first call but an array of stdClass objects for the second call if the objects are retrieved from the cache.

It looks to me like this was caused by a missed case of updating

if ( 'all' === $_fields )

to

if ( 'all' === $_fields || 'all_with_object_id' === $_fields )

in [38667]. It seems unintentional, but I might be missing something.

The attached patch includes a test demonstrating the issue and a potential patch.

[boonebgorges]

Good catch, @dlh. This does appear to be a mistake in [38667].

[boonebgorges]

In 43313:

Taxonomy: Improve cache handling when querying for terms using all_with_object_id.

When a term query using fields=all_with_object_id hits the cache, the
cached stdClass objects must be converted to WP_Term objects. This
was overlooked when WP_Term_Query was refactored to support object
queries in [38667].

Props dlh.
Fixes #44221.

[boonebgorges]

In 43314:

Taxonomy: Improve cache handling when querying for terms using all_with_object_id.

When a term query using fields=all_with_object_id hits the cache, the
cached stdClass objects must be converted to WP_Term objects. This
was overlooked when WP_Term_Query was refactored to support object
queries in [38667].

Merges [43313] to the 4.9 branch.

Props dlh.
Fixes #44221.