lei_mirror: drop git <1.8.5 support

Supporting git <1.8.5 via fetch on non-forkgroup repos would
make auto-GC dangerous, and I want to support auto-GC instead
of relying on the preciousObjects extension.

Since git 1.8.5 is 9 years old at this point, and grokmirror
(used by the only CentOS 7.x user I know of) already relies on
newer git, simplify our code and only fetch into forkgroups.

diff --git a/lib/PublicInbox/LeiMirror.pm b/lib/PublicInbox/LeiMirror.pm
index 1138a82d04f7c03d92de5134358650d8bd09b317..28fef6f949de4e2253e8db4d1ae83ca4cd5f2cd0 100644 (file)
--- a/lib/PublicInbox/LeiMirror.pm
+++ b/lib/PublicInbox/LeiMirror.pm
@@ -21,7 +21,6 @@ use PublicInbox::OnDestroy;
 use Digest::SHA qw(sha256_hex);
 
 our $LIVE; # pid => callback
-my $update_ref_stdin = $ENV{GIT_CAN_UPDATE_REF_STDIN} // 1;
 
 sub _wq_done_wait { # dwaitpid callback (via wq_eof)
        my ($arg, $pid) = @_;
@@ -279,15 +278,6 @@ sub fetch_args ($$) {
        @cmd;
 }
 
-sub fgrp_update_old ($) { # for git <1.8.5
-       my ($fgrp) = @_;
-       my $cmd = [ @{$fgrp->{-torsocks}}, 'git', "--git-dir=$fgrp->{cur_dst}",
-               fetch_args($fgrp->{lei}, my $opt = {}) ];
-       $fgrp->{lei}->qerr("# @$cmd");
-       do_reap($fgrp);
-       $LIVE->{spawn($cmd, undef, $opt)} = [ \&reap_cmd, $fgrp, $cmd ];
-}
-
 sub upr { # feed `git update-ref --stdin -z' verbosely
        my ($lei, $w, $op, $ref, $oid) = @_;
        $lei->qerr("# $op $ref $oid") if $lei->{opt}->{verbose};
@@ -324,15 +314,9 @@ sub fgrp_update {
        while (my ($ref, $oid) = each %src) {
                upr($lei, $w, 'create', $ref, $oid);
        }
-       if (close($w)) { # git >= 1.8.5
-               $LIVE->{$pid} = [ \&reap_cmd, $fgrp, $cmd ];
-               do_reap($fgrp);
-       } else { # git <1.8.5 w/o update-ref --stdin
-               warn "E: close(update-ref --stdin): $!\n";
-               $update_ref_stdin = 0;
-               waitpid($pid, 0) // die "waitpid(update-ref --stdin): $!";
-               fgrp_update_old($fgrp);
-       }
+       close($w) or warn "E: close(update-ref --stdin): $! (need git 1.8.5+)\n";
+       $LIVE->{$pid} = [ \&reap_cmd, $fgrp, $cmd ];
+       do_reap($fgrp);
 }
 
 sub pack_refs {
@@ -351,8 +335,6 @@ sub fgrp_fetched {
        my %opt = map { $_ => $fgrp->{lei}->{$_} } (0..2);
        pack_refs($fgrp, $fgrp->{-osdir}); # objstore refs always packed
 
-       $update_ref_stdin or return fgrp_update_old($fgrp);
-
        my $update_ref = PublicInbox::OnDestroy->new($$, \&fgrp_update, $fgrp);
 
        my $src = [ 'git', "--git-dir=$fgrp->{-osdir}", 'for-each-ref',
@@ -427,11 +409,18 @@ sub forkgroup_prep {
                        say $fh $l or die "say($f): $!";
                }
                close $fh or die "close($f): $!";
-               @cmd = ('git', "--git-dir=$self->{cur_dst}",
-                       qw(remote add --mirror=fetch origin), "$uri");
-               my $pid = spawn(\@cmd, undef, $opt);
-               waitpid($pid, 0) // die "waitpid(@cmd): $!";
-               die "E: @cmd: \$?=$?" if ($? && ($? >> 8) != 3);
+               $f = "$self->{cur_dst}/config";
+               open $fh, '+>>', $f or die "open:($f): $!";
+               print $fh <<EOM or die "print($f): $!";
+; rely on the "$rn" remote in the
+; $fg fork group for fetches
+; only uncomment the following iff you detach from fork groups
+; [remote "origin"]
+;      url = $uri
+;      fetch = +refs/*:refs/*
+;      mirror = true
+EOM
+               close $fh or die "close($f): $!";
        }
        bless { %$self, -osdir => $dir, -remote => $rn }, __PACKAGE__;
 }