During a recent content diff, somehow the live wp_terms table (the table with new content that we're trying to merge into the current database) was empty. This caused the function recreate_categories to not function as expected. This is because when it tries to gather all the categories which must be brought over, it does a JOIN with this wp_terms table. But if that table is empty, the query will return no results, even though the wp_terms_taxonomy table has valid categories to be imported.

This function attempts to prevent that from happening in the first place, by checking if any core WP tables are empty before proceeding in earnest with the content diff.

…ditional handling of which Core WP tables can be safely ignored.

…t-diff

Adding wp_termmeta, wp_comments, and wp_commentmeta to list of default ignored tables.

…t-diff