From 62269f4547882a20b022f6453dbdd7b78f4685c1 Mon Sep 17 00:00:00 2001
From: Eric Wong <e@80x24.org>
Date: Mon, 28 Nov 2022 05:31:49 +0000
Subject: lei_mirror: preserve permissions of existing alternates file

We don't want to be clobbering permissions when changing to
relative paths.  Furthermore, we can avoid writing to the
alternates file if there are no changes.
---
 lib/PublicInbox/LeiMirror.pm | 28 +++++++++++++++-------------
 1 file changed, 15 insertions(+), 13 deletions(-)

(limited to 'lib/PublicInbox')

diff --git a/lib/PublicInbox/LeiMirror.pm b/lib/PublicInbox/LeiMirror.pm
index d6aca800..829740bc 100644
--- a/lib/PublicInbox/LeiMirror.pm
+++ b/lib/PublicInbox/LeiMirror.pm
@@ -113,9 +113,9 @@ sub clone_cmd {
 	@cmd;
 }
 
-sub ft_rename ($$$) {
-	my ($ft, $dst, $open_mode) = @_;
-	my @st = stat($dst);
+sub ft_rename ($$$;$) {
+	my ($ft, $dst, $open_mode, $fh) = @_;
+	my @st = stat($fh // $dst);
 	my $mode = @st ? ($st[2] & 07777) : ($open_mode & ~umask);
 	chmod($mode, $ft) or croak "E: chmod($ft): $!";
 	require File::Copy;
@@ -565,19 +565,21 @@ sub v1_done { # called via OnDestroy
 		run_die([qw(git config -f), "$dst/config", 'gitweb.owner', $o]);
 	}
 	my $o = "$dst/objects";
-	if (open(my $fh, '<', "$o/info/alternates")) {
+	if (open(my $fh, '<', my $fn = "$o/info/alternates")) {;
 		my $base = File::Spec->rel2abs($o);
-		chomp(my @l = <$fh>);
+		my @l = <$fh>;
+		my $ft;
 		for (@l) {
-			$_ = File::Spec->abs2rel($_, $base) if m!\A/!;
-			$_ .= "\n";
+			next unless m!\A/!;
+			$_ = File::Spec->abs2rel($_, $base);
+			$ft //= File::Temp->new(TEMPLATE => '.XXXX',
+						DIR => "$o/info");
+		}
+		if ($ft) {
+			print $ft @l or die "print($ft): $!";
+			$ft->flush or die "flush($ft): $!";
+			ft_rename($ft, $fn, 0666, $fh);
 		}
-		my $f = File::Temp->new(TEMPLATE => '.XXXX', DIR => "$o/info");
-		print $f @l;
-		$f->flush or die "flush($f): $!";
-		rename($f->filename, "$o/info/alternates") or
-			die "rename($f, $o/info/alternates): $!";
-		$f->unlink_on_destroy(0);
 	}
 	pack_refs($self, $dst) if delete $self->{-do_pack_refs};
 	eval { set_description($self) };
-- 
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