+ fproblems_maybe_bail();
+
+ my $new_bw;
+
+ fresh_workarea();
+ in_workarea sub {
+ my @upstream_merge_parents;
+
+ if (!any_fproblems()) {
+ push @upstream_merge_parents, $old_upstream->{CommitId};
+ }
+
+ foreach my $pc (@newpieces) { # always has '' first
+ if ($pc->{Name}) {
+ read_tree_subdir $pc->{Name}, $pc->{New};
+ } else {
+ runcmd @git, qw(read-tree), $pc->{New};
+ }
+ push @upstream_merge_parents, $pc->{New};
+ }
+
+ # index now contains the new upstream
+
+ if (@newpieces > 1) {
+ # need to make the upstream subtree merge commit
+ $new_upstream = make_commit \@upstream_merge_parents,
+ [ "Combine upstreams for $new_upstream_version",
+ ("[git-debrebase upstream-combine . ".
+ (join " ", map { $_->{Name} } @newpieces[1..$#newpieces]).
+ ": new upstream]"),
+ ];
+ }
+
+ # $new_upstream is either the single upstream commit, or the
+ # combined commit we just made. Either way it will be the
+ # "upstream" parent of the breakwater special merge.
+
+ read_tree_subdir 'debian', "$old_bw:debian";
+
+ # index now contains the breakwater merge contents
+ $new_bw = make_commit [ $old_bw, $new_upstream ],
+ [ "Update to upstream $new_upstream_version",
+ "[git-debrebase breakwater: new upstream $new_upstream_version, merge]",
+ ];
+
+ # Now we have to add a changelog stanza so the Debian version
+ # is right.
+ die if unlink "debian";
+ die $! unless $!==ENOENT or $!==ENOTEMPTY;
+ unlink "debian/changelog" or $!==ENOENT or die $!;
+ mkdir "debian" or die $!;
+ open CN, ">", "debian/changelog" or die $!;
+ my $oldclog = git_cat_file ":debian/changelog";
+ $oldclog =~ m/^($package_re) \(\S+\) / or
+ fail "cannot parse old changelog to get package name";
+ my $p = $1;
+ print CN <<END, $oldclog or die $!;
+$p ($new_version) UNRELEASED; urgency=medium
+
+ * Update to new upstream version $new_upstream_version.
+
+ --
+
+END
+ close CN or die $!;
+ runcmd @git, qw(update-index --add --replace), 'debian/changelog';
+
+ # Now we have the final new breakwater branch in the index
+ $new_bw = make_commit [ $new_bw ],
+ [ "Update changelog for new upstream $new_upstream_version",
+ "[git-debrebase: new upstream $new_upstream_version, changelog]",
+ ];
+ };
+
+ # we have constructed the new breakwater. we now need to commit to
+ # the laundering output, because git-rebase can't easily be made
+ # to make a replay list which is based on some other branch
+
+ update_head_postlaunder $old_head, $old_laundered_tip,
+ 'launder for new upstream';
+
+ my @cmd = (@git, qw(rebase --onto), $new_bw, $old_bw, @ARGV);
+ runcmd @cmd;
+ # now it's for the user to sort out
+}
+
+sub cmd_gbp2debrebase () {
+ badusage "needs 1 optional argument, the upstream" unless @ARGV<=1;
+ my ($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, $old_head) {
+ fproblem 'upstream-not-ancestor',
+ "upstream ($upstream) is not an ancestor of HEAD";
+ } else {
+ my $wrong = cmdoutput
+ (@git, qw(rev-list --ancestry-path), "$upstream..HEAD",
+ qw(-- :/ :!/debian));
+ if (length $wrong) {
+ fproblem 'unexpected-upstream-changes',
+ "history between upstream ($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-has-debian',
+ "upstream ($upstream) contains debian/ directory";
+ }
+
+ fproblems_maybe_bail();
+
+ my $work;
+
+ fresh_workarea();
+ in_workarea sub {
+ runcmd @git, qw(checkout -q -b gdr-internal), $old_head;
+ # make a branch out of the patch queue - we'll want this in a mo
+ runcmd qw(gbp pq import);
+ # strip the patches out
+ runcmd @git, qw(checkout -q gdr-internal~0);
+ rm_subdir_cached 'debian/patches';
+ $work = make_commit ['HEAD'], [
+ 'git-debrebase import: drop patch queue',
+ 'Delete debian/patches, as part of converting to git-debrebase format.',
+ '[git-debrebase: gbp2debrebase, drop patches]'
+ ];
+ # make the breakwater pseudomerge
+ # the tree is already exactly right
+ $work = make_commit [$work, $upstream], [
+ 'git-debrebase import: declare upstream',
+ 'First breakwater merge.',
+ '[git-debrebase breakwater: declare upstream]'
+ ];
+
+ # rebase the patch queue onto the new breakwater
+ runcmd @git, qw(reset --quiet --hard patch-queue/gdr-internal);
+ runcmd @git, qw(rebase --quiet --onto), $work, qw(gdr-internal);
+ $work = get_head();
+ };
+
+ update_head_checkout $old_head, $work, 'gbp2debrebase';
+}
+
+sub cmd_downstream_rebase_launder_v0 () {
+ badusage "needs 1 argument, the baseline" unless @ARGV==1;
+ my ($base) = @ARGV;
+ $base = git_rev_parse $base;
+ my $old_head = get_head();
+ my $current = $old_head;
+ my $topmost_keep;
+ for (;;) {
+ if ($current eq $base) {
+ $topmost_keep //= $current;
+ print " $current BASE stop\n";
+ last;
+ }
+ my $cl = classify $current;
+ print " $current $cl->{Type}";
+ my $keep = 0;
+ my $p0 = $cl->{Parents}[0]{CommitId};
+ my $next;
+ if ($cl->{Type} eq 'Pseudomerge') {
+ print " ^".($cl->{Contributor}{Ix}+1);
+ $next = $cl->{Contributor}{CommitId};
+ } elsif ($cl->{Type} eq 'AddPatches' or
+ $cl->{Type} eq 'Changelog') {
+ print " strip";
+ $next = $p0;
+ } else {
+ print " keep";
+ $next = $p0;
+ $keep = 1;
+ }
+ print "\n";
+ if ($keep) {
+ $topmost_keep //= $current;
+ } else {
+ die "to-be stripped changes not on top of the branch\n"
+ if $topmost_keep;
+ }
+ $current = $next;
+ }
+ if ($topmost_keep eq $old_head) {
+ print "unchanged\n";
+ } else {
+ print "updating to $topmost_keep\n";
+ update_head_checkout
+ $old_head, $topmost_keep,
+ 'downstream-rebase-launder-v0';
+ }
+}
+
+GetOptions("D+" => \$debuglevel,
+ 'noop-ok', => \$opt_noop_ok,
+ 'f=s' => \@fproblem_force_opts,
+ 'force!') or die badusage "bad options\n";
+initdebug('git-debrebase ');
+enabledebug if $debuglevel;
+
+my $toplevel = cmdoutput @git, qw(rev-parse --show-toplevel);
+chdir $toplevel or die "chdir $toplevel: $!";
+
+$rd = fresh_playground "$playprefix/misc";
+
+if (!@ARGV || $ARGV[0] =~ m{^-}) {
+ defaultcmd_rebase();
+} else {
+ my $cmd = shift @ARGV;
+ my $cmdfn = $cmd;
+ $cmdfn =~ y/-/_/;
+ $cmdfn = ${*::}{"cmd_$cmdfn"};
+
+ $cmdfn or badusage "unknown git-debrebase sub-operation $cmd";
+ $cmdfn->();
+}