What I did, and my findings:
I installed commerce_product_bundles module for D7, and found that it leaves 5 orphaned
field_config_instances in the database after uninstalling:
commerce_unit_price, commerce_total, commerce_product, commerce_display_path, commerce_parent_line_item
I think these are left because the module lacks a proper uninstall script, but I am not sure about that. The instances are all of the
commerce_line_item entity type, and the
bundle bundle type, so they seem to be distinct from the other commerce config instances with similar names.
I found these from Notices in the log when visiting
admin/reports/fields, as there are the following 2 notices for each of the 5 instances:
Notice: Undefined index: bundle in field_ui_fields_list() (line 35 of /*/*/*/code/modules/field_ui/field_ui.admin.inc). Notice: Undefined index: bundle in _field_ui_bundle_admin_path() (line 335 of /*/*/*/code/modules/field_ui/field_ui.module).
What I've done:
Reinstalling the module removes the notices.
I have deleted these
field_config_instances locally in my dev environment to test, and haven't noticed anything adverse, but that doesn't give me enough piece of mind to delete them permanently.
I also reinstalled and looked for fields that would relate to those instances and found none.
Is there a best practice to check the database for fields or data that might be hanging around relative to these instances? Or is there a way to check the database before and after removing them in a test environment to ensure nothing was corrupted in removing them?
I have access to phpMyAdmin, and drush, but am very new to database work.
Maybe a patch should be written to safely remove those instances upon uninstalling the module... I could open an issue for that, but the question is still pertinent.