git-debrebase: wip gbp2debrebase

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

diff --git a/git-debrebase b/git-debrebase
index b70f8d91ff1f0824dd24cdd0fc3c1c643ddabf20..50f5e1674c6574afa7d42c8e7d04a33c31b99867 100755 (executable)
--- a/git-debrebase
+++ b/git-debrebase
@@ -990,6 +990,45 @@ END
     # now it's for the user to sort out
 }
 
+sub cmd_gbp2debrebase () {
+    badusage "needs 1 optional argument, the upstream" unless @ARGV<=1;
+    my ($upstream_spec) = @ARGV;
+    $upstream_spec //= 'refs/heads/upstream';
+    my $upstream = git_rev_parse $upstream_spec;
+    my $old_head = get_head();
+
+    my $upsdiff = get_differs $upstream, $old_head;
+    if ($upsdiff & D_UPS) {
+       runcmd @git, qw(--no-pager diff),
+           $upstream, $old_head,
+           qw( -- :!/debian :/);
+ fail "upstream ($upstream_spec) and HEAD are not identical in upstream files";
+    }
+
+    if (!is_fast_fwd $upstream, $old_head) {
+       fproblem "upstream ($upstream) is not an ancestor of HEAD";
+    } else {
+       my $wrong = cmdoutput
+           (@git, qw(rev-list --ancestry-path), "$upstream..HEAD",
+            qw(-- :/ :!/debian));
+       if (length $wrong) {
+           fproblem "history between upstream ($upstream) and HEAD contains direct changes to upstream files - are you sure this is a gbp (patches-unapplied) branch?";
+           print STDERR "list expected changes with:  git log --stat --ancestry-path $upstream_spec..HEAD -- :/ ':!/debian'\n";
+       }
+    }
+
+    if ((git_cat_file "$upstream:debian")[0] ne 'missing') {
+       fproblem "upstream ($upstream) contains debian/ directory";
+    }
+    die;
+
+    fresh_workarea();
+    in_workarea sub {
+       runcmd @git, qw(checkout -b work), $old_head;
+       
+    };
+}
+
 sub cmd_downstream_rebase_launder_v0 () {
     badusage "needs 1 argument, the baseline" unless @ARGV==1;
     my ($base) = @ARGV;