In my ~/.hgrc, I've got [defaults] qseries = -sv Whenever I'm completing something that uses qseries internally, like the completion _hg_cmd_qgoto, all of the other output gets thrown into the completions (i.e., numbers, "A", the words in the descriptions of the patches, etc). Also, and this is worse from a usability point of view, the colons qseries -s appends to the patch names aren't stripped off.
I think that is one of the reasons defaults are deprecated. I doubt we will do anything to fix that.
What about making bash_completion use HGPLAIN? It seems like a quintessential case for it.
Here's a patch that makes the completion use HGPLAIN: http://www.selenic.com/pipermail/mercurial-devel/2010-July/023010.html
Fixed by http://hg.intevation.org/mercurial/crew/rev/91af149b5cd7 (bash/zsh completion: use HGPLAIN when invoking hg (issue2297))
--- Bug imported by bugzilla@serpentine.com 2012-05-12 09:11 EDT --- This bug was previously known as _bug_ 2297 at http://mercurial.selenic.com/bts/issue2297