Version:           2.3 (using Devel) 
OS:                Linux

1) double-click on an entry to open it
2) type something into an empty field or change an existing field
3) click close
4) click discard
   --> the entry is not bolded
   --> the collection is not marked as having a change (title bar
doesn't include '[modified]')
5) double-click on the entry again
   --> the text I entered is (incorrectly) still there

At this point, if I select a different entry and then re-select the
initial entry, the text will be properly discarded.  I selected a
different entry, made & saved a change there, and then saved the
Tellico file; when I re-opened the file the discarded text was
(correctly) still gone.

To cause potential data loss: repeat steps 1-5, then:
6) edit another field
7) click close
8) click save entry
   --> the original, "discarded" change gets (incorrectly) applied

This could cause data loss in the case where a user edits an entry,
makes a mistake and wants to 'start over', closes the entry and
discards their changes, then re-edits the entry.  A bit of a corner
case, but could catch someone who isn't paying close attention or
making changes in multiple categories (tabs).

Reproducible: Didn't try