Originally filed as issue #212501.
The problem is that there is no way to specify the encoding of the file for the diff action. This is problem if one is diffing temporary files of a project - project has some encoding but the temporary file has the system default encoding (since it is typically in the TEMP directory).
Heh, sorry; of course, this is an enhancement.
BTW I just noticed that currently there are already 3 FEQs in the IDE:
PROVIDER org.netbeans.modules.versioning.ui.diff.DiffFileEncodingQueryImpl @1
PROVIDER org.netbeans.modules.versioning.util.queries.DiffFileEncodingQueryImpl @1
PROVIDER org.netbeans.modules.php.project.connections.sync.diff.DiffFileEncodingQueryImpl @2