git-debrebase: stitch better

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

diff --git a/git-debrebase b/git-debrebase
index 5fcec5461a2e51143de9818b50ad09aa6e0516db..a853c0639c1cf1f0daad4f891e0c3838c1912b87 100755 (executable)
--- a/git-debrebase
+++ b/git-debrebase
@@ -1150,15 +1150,23 @@ sub cmd_stitch () {
     if (!$prev) {
        fail "No ffq-prev to stitch." unless $opt_noop_ok;
     }
     if (!$prev) {
        fail "No ffq-prev to stitch." unless $opt_noop_ok;
     }

-    $prose = ", $prose" if length $prose;
-    runcmd @git, qw(merge -s ours --no-edit -m), <<END;
-Declare fast forward / record previous work
-
-[git-debrebase pseudomerge: stitch$prose]
+    fresh_workarea();
+    my $old_head = get_head();
+    my $new_head = make_commit [ $old_head, $ffq_prev ], [
+       'Declare fast forward / record previous work',
+        "[git-debrebase pseudomerge: stitch$prose]",
+    ];
+    my @upd_cmd = (@git, qw(update-ref --stdin));
+    debugcmd '>|', @upd_cmd;
+    open U, "|-", @upd_cmd or die $!;
+    my $u = <<END;
+update HEAD $new_head $old_head
+delete $ffq_prev $prev

 END
 END

-    # xxx should delete old ffq-prev
-    # xxx should avoid making pseudomerge if not needed
-    # xxx should make pseudomerge in temp tree so can do atomic update
+    printdebug ">= ", $_, "\n" foreach split /\n/, $u;
+    print U $u;
+    printdebug ">\$\n";
+    close U or failedcmd @upd_cmd;

 }
 
 sub cmd_gbp2debrebase () {
 }
 
 sub cmd_gbp2debrebase () {