[PATCH] lei_mirror: do not needlessly rewrite project-list

[Eric Wong]

No need to cause extra wear on storage devices.
---
 lib/PublicInbox/LeiMirror.pm | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/lib/PublicInbox/LeiMirror.pm b/lib/PublicInbox/LeiMirror.pm
index db249ece..87abf88c 100644
--- a/lib/PublicInbox/LeiMirror.pm
+++ b/lib/PublicInbox/LeiMirror.pm
@@ -1056,7 +1056,8 @@ EOM
 
        my (undef, $dn, $bn) = File::Spec->splitpath($f);
        $self->{chg}->{nr_chg} += scalar(@remote) + scalar(@local);
-       atomic_write($dn, $bn, join("\n", @list, ''));
+       my $new = join("\n", @list, '');
+       atomic_write($dn, $bn, $new) if $new ne $old;
 }
 
 # FIXME: this gets confused by single inbox instance w/ global manifest.js.gz