Deleting an unused fieldset tries to also delete a regular in-use field

[adrianbj]

I don't have a great deal of info on this one yet, but twice within a few minutes I tried to delete an unused fieldset field and it resulted in an exception page saying that Unable to delete field 'my_field_name' because it is in use by these fieldgroups: 'message'

I tried this on a dev and testing server for the same site and both times I tried to delete an unused fieldset field and it randomly tried to delete a field that is being used. The report field that couldn't be deleted was different each time.

Makes me think that maybe at some point these fields were in the fieldset that I deleted (which was successfully deleted), but at this stage I don't really know, but it feels a bit dangerous.

[adrianbj]

Just happened again a couple more times, one was a regular fieldset and the other was a fieldset tab. For the latter it then tried to delete the _END' version of a different fieldset field so it seems like it's completely random what it tries to accidentally delete.

[adrianbj]

This might or not be related but this time when I tried to delete a page reference field I got:
SQLSTATE[42S02]: Base table or view not found: 1051 Unknown table 'mydb.field_my_field'