Calling Message.tags_to_maildir_flags() when the database has been opened with a relative path results in a corrupted filename entry in the database. The actual filename is changed properly but the filename in the database gets the relative path prepended. As I understand it's expected that the database path should be absolute but corrupting the database when the path is relative sounds dangerous. Attached is a python script showing the problem. Run it as follows: python ./retag_bug.py db_path +tag,-tag search_query Also attached is the output showing the problem.
$ notmuch search thread:00000000000005a2 thread:00000000000005a2 March 07 [1/1] Mathieu de Verdiere; [fablab brest] Echange PC DUINO contre ARDUINO MEGA+ramp? (inbox unread) $ python2 ./test.py ./maildir/ -unread thread:00000000000005a2 Using db at ./maildir/ Changing tags: -unread Search query: thread:00000000000005a2 Adding tags: [] Removing tags: ['unread'] Filename: ./maildir/cur/1425822991_0.10764.minux,U=2618,FMD5=7b0d668e0b18d8601b8bce4eec0ed930:2, Retagging thread:00000000000005a2 Adding [] Removing ['unread'] Sync maildir: True Found 1 messages to retag Retag done Filename: ./maildir/./maildir/cur/1425822991_0.10764.minux,U=2618,FMD5=7b0d668e0b18d8601b8bce4eec0ed930:2,S