git-debrebase: new-upstream-v0: use make_commit another time (nfc)

Signed-off-by: Ian Jackson <ijackson@chiark.greenend.org.uk>

1 files changed, 6 insertions, 9 deletions

diff --git a/git-debrebase b/git-debrebase
index df5d27e..db132e3 100755
--- a/git-debrebase
+++ b/git-debrebase
@@ -939,15 +939,12 @@ sub cmd_new_upstream_v0 () {
 
 	if (@newpieces > 1) {
 	    # need to make the upstream subtree merge commit
-	    my $us_tree = cmdoutput @git, qw(write-tree);
-	    my @cmd = (@git, qw(commit-tree), $us_tree);
-	    push @cmd, qw(-p), $_ foreach @upstream_merge_parents;
-	    push @cmd, qw(-m), "Combine upstreams for $new_upstream_version";
-	    push @cmd, qw(-m),
-		"[git-debrebase new-upstream combine . ".
-		(join " ", map { $_->{Name} } @newpieces[1..$#newpieces]).
-		 "]";
-	    $new_upstream = cmdoutput @cmd;
+            $new_upstream = make_commit \@upstream_merge_parents,
+                [ "Combine upstreams for $new_upstream_version",
+                  ("[git-debrebase new-upstream combine . ".
+                   (join " ", map { $_->{Name} } @newpieces[1..$#newpieces]).
+                   "]"),
+                ];
 	}
 
 	# $new_upstream is either the single upstream commit, or the