[PATCH] Import.pm: When purging replace a purged file with a zero length file

[ebiederm@xmission.com (Eric W. Biederman)]

This ensures that the number of added files remains the same and thus
the article numbers derived from a repository will remain the same.

I think this is the last place in public-inbox that has to be tweaked to
guarantee the generated article number will remain the same in an public
inbox archive.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
---
 lib/PublicInbox/Import.pm | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/lib/PublicInbox/Import.pm b/lib/PublicInbox/Import.pm
index bfa7a8053297..3df7d98f298b 100644
--- a/lib/PublicInbox/Import.pm
+++ b/lib/PublicInbox/Import.pm
@@ -519,11 +519,12 @@ sub purge_oids {
 			push @buf, $buf;
 		} elsif (/^M 100644 ([a-f0-9]+) (\w+)/) {
 			my ($oid, $path) = ($1, $2);
+			$tree->{$path} = 1;
 			if ($purge->{$oid}) {
 				push @oids, $oid;
-				delete $tree->{$path};
+				my $cmd = "M 100644 inline $path\ndata 0\n\n";
+				push @buf, $cmd;
 			} else {
-				$tree->{$path} = 1;
 				push @buf, $_;
 			}
 		} elsif (/^D (\w+)/) {
-- 
2.17.1