On Wed, 9 Feb 2011 13:36:17 -0500, Jesse Rosenthal <jrosenthal@jhu.edu> wrote:
> 
> On Wed, 09 Feb 2011 13:22:26 -0500, Daniel Kahn Gillmor <dkg@fifthhorseman.net> wrote:
> > 
> > Jameson, are you saying that "Search Oldest First" not only inverts the
> > order of the threads, but also changes the a date a given thread is
> > associated with?  
> 
> The procedure is to match threads by either the oldest matching message
> (in oldest first) or newest matching message (in newest first). So
> matching newest first will make the thread with new messages go to the
> top. But in oldest first -- which is what I imagine Sebastian was
> looking at in the inbox -- the thread with an older inbox message will
> appear further up.
> 
> So if Sebastian's message is tagged "inbox" this thread will appear,
> under oldest-first, when he sent it; if it's not but Jamie's is, then it
> will appear under Jamie's. But it'll appear under mine regardless in
> newest first. I don't believe emacs has anything to do with it -- it's
> how the nm binary orders threads as output to "search."

aha!
I knew about the 'o' toggle that one could play with to display the
threads, but I didn't notice this also modified how their ordering
worked out: 
 I naively thought it was just a matter of reverting the list.

so, say I have the following messages and threads:
 id_0 1/3 [important meeting] - (received Monday)
 id_1 2/3  [important meeting] - (received Tuesday)
 id_2 1/1 [pick groceries] - (received Wednesday)
 id_3 3/3   [important meeting] - (received Thursday)
 id_4 1/1 [another title] - (received Friday morning)

if I have 'Search Oldest first' "on", I'd get the following
 id_0 [and id_1 and id_3 folded in]
 id_2 
 id_4

and if it is "off":
 id_4
 id_0 [and id_1 and id_3 folded in]
 id_2

but what I'd like to have is instead:
 id_2
 id_0 [and id_1 and id_3 folded in]
 id_4

id_0 and friends come after id_2 because id_3 is more recent than id_2
but older than id_4

so: oldest first but only the latest of the messages of a thread to be
considered for the thread-to-thread ordering.

I prefer to process my emails like a stack growing from top to bottom ;)

-s