Re: for-each-ref output order change in 2.7.0

Hi,

Cc-ing Karthik to draw his attention on the message.

----- Original Message -----

In one of our tests, we have a set of branches whose names are all
special characters (%, @, etc). Most of them branches have identical
tip commits and just have different names. In 2.7.0, when ordering by
-committerdate, the branches are now returned in a different order. I
don't think this is a bug, based on the commit it bisects to, but I'm
wondering if someone can confirm.

2.6.5 and prior (tested all the way back to 1.7.6, so this was
consistent for a long time):

refs/heads/!@#% -> Tue Jan 3 17:04:06 2012 +1100
refs/heads/!@#$% -> Tue Jan 3 17:00:51 2012 +1100
refs/heads/% -> Tue Jan 3 17:00:51 2012 +1100
refs/heads/@#$% -> Tue Jan 3 17:00:51 2012 +1100
refs/heads/@#% -> Tue Jan 3 17:00:51 2012 +1100

2.7.0:

refs/heads/!@#% -> Tue Jan 3 17:04:06 2012 +1100
refs/heads/@#% -> Tue Jan 3 17:00:51 2012 +1100
refs/heads/@#$% -> Tue Jan 3 17:00:51 2012 +1100
refs/heads/% -> Tue Jan 3 17:00:51 2012 +1100
refs/heads/!@#$% -> Tue Jan 3 17:00:51 2012 +1100

I've bisected this back to:

bturner@ubuntu:~/Development/oss/git/git$ git bisect bad
9e468334b41c1d1fc715de177ef1f61a36c1cf01 is the first bad commit
commit 9e468334b41c1d1fc715de177ef1f61a36c1cf01
Author: Karthik Nayak [off-list ref]
Date:   Fri Oct 30 14:15:28 2015 +0530

    ref-filter: fallback on alphabetical comparison

The message for that commit indicates that sorting numerics (which I
assume is the implementation for committerdate) now falls back on
alphabetical for identical values, suggesting this order change is
actually intentional and correct.

And also that the previous order was arbitrary (just letting the sort
algorithm chose which one to put first in case of equality on the main
sorting criterion), so the fact that it was stable previously is more
or less just luck. Now it should be stable.

Is that right?

(Note: The alphabetical-ness of the branch names is reversed, which
seems logical given my original sort was -committerdate. A
--sort=refname looks like this.

refs/heads/!@#$% -> Tue Jan 3 17:00:51 2012 +1100
refs/heads/!@#% -> Tue Jan 3 17:04:06 2012 +1100
refs/heads/% -> Tue Jan 3 17:00:51 2012 +1100
refs/heads/@#$% - >Tue Jan 3 17:00:51 2012 +1100
refs/heads/@#% -> Tue Jan 3 17:00:51 2012 +1100

That's probably more correct too.)

Best regards,
Bryan Turner

-- 
Matthieu Moy
http://www-verimag.imag.fr/~moy/