Bug#281521: juk mangles id3v2 tags

[D Roland Walker <walker@pobox.com>]

As this bug causes data loss and breakage in other programs, it should
be upgraded to grave or critical.

I'm attaching this to 281521, as it sounds similar.  I guess it
may in fact be a bug in libtag1.  What else depends on it libtag1?

juk does not delete the id3v2 tags, just mangles them beyond the
recognition of most other software.

Once a tag has been edited in juk, it cannot be read by for example

   id3v2
   xmms
   iTunes

however, the id3v2 information is still present, and readable by

   juk
   eyeD3

eyeD3 does not show the same symptom (touch the tag once, and it
becomes unreadable by other programs) but it is not able to rescue
the tag upon edit.  Only complete deletion of the tag

   id3v2 --delete-v2

and recreation of it seems to work.

In all cases I observed, juk had done an update from id3v2.3 to
id3v2.4.  But other id3v2.4-capable software still could not read the
tags.