[PATCH] export: show 'Date' header in a format that also is readable for humans

[Matt Mackall]

On Sun, 2013-02-10 at 13:12 +0100, Mads Kiilerich wrote:
> On 02/10/2013 12:53 PM, Brodie Rao wrote:
> > On Sat, Feb 9, 2013 at 9:31 AM, Mads Kiilerich <mads at kiilerich.com> wrote:
> >> # HG changeset patch
> >> # User Mads Kiilerich <mads at kiilerich.com>
> >> # Date 1360360457 -3600
> >> # Node ID 055060daf58dbe46c667053cbb04409b202ee9cd
> >> # Parent  97761496c65ae836d6b0983a3f48959dd3112364
> >> export: show 'Date' header in a format that also is readable for humans
> >>
> >> 'export' is the official export format and used by patchbomb, but it would only
> >> show date as a timestamp that most humans might find it hard to relate to. It
> >> would be very convenient when reviewing a patch to be able to see what
> >> timestamp the patch will end up with.
> >>
> >> Mercurial has always used util.parsedate for parsing these headers. It can
> >> handle 'all' date formats, so we could just as well use a readable one.
> > Are there any third party utilities that parse these headers? I wonder
> > if this might cause other tools to break.
> 
> Yes, that is a valid concern, but we don't expect that. Parsers should 
> read it as Mercurial do, and Mercurial has always been able to handle 
> all formats.
> 
> So I will put it in 'default' and we can wait and see if it really 
> becomes a problem.

After a bit of poking, I've discovered this in Git:

        hg)
                this=0
                for hg in "$@"
                do
                        this=$(( $this + 1 ))
                        msgnum=$(printf "%0${prec}d" $this)
                        # hg stores changeset metadata in #-commented lines preceding                                                          
                        # the commit message and diff(s). The only metadata we care about                                                      
                        # are the User and Date (Node ID and Parent are hashes which are                                                       
                        # only relevant to the hg repository and thus not useful to us)                                                        
                        # Since we cannot guarantee that the commit message is in                                                              
                        # git-friendly format, we put no Subject: line and just consume                                                        
                        # all of the message as the body                                                                                       
                        LANG=C LC_ALL=C perl -M'POSIX qw(strftime)' -ne 'BEGIN { $subject = 0 }                                                
                                if ($subject) { print ; }                                                                                      
                                elsif (/^\# User /) { s/\# User/From:/ ; print ; }                                                             
                                elsif (/^\# Date /) {                                                                                          
                                        my ($hashsign, $str, $time, $tz) = split ;                                                             
                                        $tz = sprintf "%+05d", (0-$tz)/36;                                                                     
                                        print "Date: " .                                                                                       
                                              strftime("%a, %d %b %Y %H:%M:%S ",                                                               
                                                       localtime($time))                                                                       
                                              . "$tz\n";                                                                                       
                                } elsif (/^\# /) { next ; }                                                                                    
                                else {                                                                                                         
                                        print "\n", $_ ;                                                                                       
                                        $subject = 1;                                                                                          
                                }                                                                                                              
                        ' <"$hg" >"$dotest/$msgnum" || clean_abort


so we're going to try something different.


-- 
Mathematics is the supreme nostalgia of our time.