v7.11.2
Discovered this bug (more of an undesired feature) today, kinda surprised I hadn’t noticed it sooner. Could be new, but my guess is that it’s as old as record merging is.
If you attempt to merge two or more records in a table with a field that requires uniqueness, the merge dialog will block the merge because the new record would be using a value that “already exists” and therefore is non-unique. In the example below, Collecting Event # is required to be unique, and merging was blocked until I removed the desired value from the field.
The expected behavior is that the merge tool should recognize that the only other instance of a unique value is the record to be merged, and allow you to merge the records because the “duplication” of the unique value is only ever temporarily present in the merge dialog window.
This does seem a bit tricky – you don’t want to make it so uniqueness rules don’t apply in merging (seems dangerous) but the current behavior requires that you temporarily alter data to be unique, incorrect, and compliant with any other formatting rules for the field in order for a merge to proceed.