It is not a bug, but a request.
Thanks to the developers for their efforts, but in some cases need to create separate midi files. Such a situation exists and it is strange that no one noticed.
Starting with version 3.5-388-g74bc0c8 and includes the current release:
the import midi files from “rosegarden” as “one track per channel” does not create in the folder …/midifiles as many files as tracks present in the imported midi file.
For example, open the file: https://cloud.mail.ru/public/65ddfb97dd53%2Ftest_multitrack.mid
Then open it as a “one track per channel” in the revision g08a1409.
So 3.5-387-g08a1409 (back port 6576105 from cairocanvas as fix for data loss/file deletion) is the latest working revision for me.
Need to fix a separate import midi files from one during the session. It is necessary for use Ardour3 & linuxsampler.