git-cvsimport: port to SHA-256

Instead of calling the function is_sha1, call it is_oid and update it to
match either a SHA-1 or a SHA-256 hex object ID.

Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Acked-by: Eric Wong <e@80x24.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

git-cvsimport.perl

@@ -637,9 +637,9 @@ sub getwd() {
 	return $pwd;
 }
 
-sub is_sha1 {
+sub is_oid {
 	my $s = shift;
-	return $s =~ /^[a-f0-9]{40}$/;
+	return $s =~ /^[a-f0-9]{40}(?:[a-f0-9]{24})?$/;
 }
 
 sub get_headref ($) {
@@ -810,7 +810,7 @@ sub write_tree () {
 	open(my $fh, '-|', qw(git write-tree))
 		or die "unable to open git write-tree: $!";
 	chomp(my $tree = <$fh>);
-	is_sha1($tree)
+	is_oid($tree)
 		or die "Cannot get tree id ($tree): $!";
 	close($fh)
 		or die "Error running git write-tree: $?\n";
@@ -896,7 +896,7 @@ sub commit {
 
 	print "Committed patch $patchset ($branch $commit_date)\n" if $opt_v;
 	chomp(my $cid = <$commit_read>);
-	is_sha1($cid) or die "Cannot get commit id ($cid): $!\n";
+	is_oid($cid) or die "Cannot get commit id ($cid): $!\n";
 	print "Commit ID $cid\n" if $opt_v;
 	close($commit_read);