Tab completion doesn't work on multi-line commands

[Benjamin J. Tilly]

I find myself often typing something like this:

  btilly@localhost:~/cvs$ cvs commit -m 'Some long message
  that breaks across lines for formatting reasons.

  And ends, say, here' path/to/file1 other/path/to/file2

Unfortunately tab-completion won't help me type in the files
because by the time I get to that line, bash has lost track
of the fact that I am in the middle of a quoted construct.
It would be nice if bash could figure that out and Do The
Right Thing.

(My current workaround is to hit return again, type out the
file names using tab, then Ctrl-a to the beginning of the line
and add the closing quote.)

Cheers,
Ben