clone|fetch: preserve mtime of modified manifest.js.gz

When we cull manifest.js.gz for ignored epochs, attempt to
preserve mtime of the updated manifest.js.gz since it can
be used to optimize future fetches.

1 files changed, 2 insertions, 0 deletions

diff --git a/lib/PublicInbox/Fetch.pm b/lib/PublicInbox/Fetch.pm
index 5261cad1..364271e8 100644
--- a/lib/PublicInbox/Fetch.pm
+++ b/lib/PublicInbox/Fetch.pm
@@ -221,7 +221,9 @@ EOM
                 if ($mculled) {
                         my $json = PublicInbox::Config->json->encode($m1);
                         my $fn = $ft->filename;
+                        my $mtime = (stat($fn))[9];
                         gzip(\$json => $fn) or die "gzip: $GzipError";
+                        utime($mtime, $mtime, $fn) or die "utime(..., $fn): $!";
                 }
                 PublicInbox::LeiMirror::ft_rename($ft, $mf, 0666);
         }