3 # Script helping make fast-forwarding histories while still rebasing
4 # upstream deltas when working on Debian packaging
6 # Copyright (C)2017 Ian Jackson
8 # This program is free software: you can redistribute it and/or modify
9 # it under the terms of the GNU General Public License as published by
10 # the Free Software Foundation, either version 3 of the License, or
11 # (at your option) any later version.
13 # This program is distributed in the hope that it will be useful,
14 # but WITHOUT ANY WARRANTY; without even the implied warranty of
15 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 # GNU General Public License for more details.
18 # You should have received a copy of the GNU General Public License
19 # along with this program. If not, see <http://www.gnu.org/licenses/>.
21 # git-debrebase new-upstreams-v0 \
22 # NEW-VERSION ORIG-COMMITISH
23 # [EXTRA-ORIG-NAME EXTRA-ORIG-COMMITISH ...]
26 # git-debrebase status
27 # git-debrebase start # like ffqrebase start + debrebase launder
28 # git-debrebase new-upstream [stuff] # see below
29 # git-debrebase <git-rebase options> # does debrebase start if necessary
31 # git-debrebase analyse
32 # git-debrebase launder # prints breakwater tip
33 # git-debrebase create-new-upstream-breakwater [-f] <upstreaminfo>...
36 # [,][<subdir>:][+]<commitid>[,...]
38 # if initial comma is supplied, entries are not positional. Unspecified
39 # <subdir> means root (and there may be only one).
40 # xxx want auto branch names
43 # [+]<commit> [<subdir/> [+]<commit>...]
45 # --new-upstream-different-subtrees
48 # git-debrebase new-upstream
49 # - previous breakwater merge must be gdr-generated
50 # - orig set is the same as before
51 # - implicitly uses upstream branches according to orig set
52 # - not all upstream branches need be updated
53 # - insists on fast-forward of each branch, unless
54 # --force (or --force=<subdir>[/])
55 # branch set adjustments
56 # git-debrebase new-upstream --add <subdir>/
57 # git-debrebase new-upstream --rm <subdir>/
58 # git-debrebase new-upstream / [<subdir>/ ...]
59 # - orig set is adjusted
60 # - otherwise like auto (--add is not checked for ffness, obv)
61 # - multiple --add and --rm may be specified
62 # - --add makes new upstream the last contributor
64 # git-debrebase / [<rootcommitid>] [<subdir>/ [<commitid>] ...]
65 # - orig set is precisely as specified now
66 # - previous breakwater merge is irrelevant
67 # - no fast forward checks
68 # for now only explicit with commitids
70 # implicitly uses `upstream'
71 # # (or multiple other branches)
72 # git-debrebase new-upstream \
73 # [<subdir>/]=<commitid>
75 # UPSTREAM[,[[SUBDIR:]SUBUPSTREAM]
76 # default for SUBDIR: is from previous upstream merge[xxx terminology]
80 # when starting must record original start (for ff)
81 # and new rebase basis
83 # git-ffqrebase start [BASE]
84 # # records previous HEAD so it can be overwritten
85 # # records base for future git-ffqrebase
86 # git-ffqrebase set-base BASE
87 # git-ffqrebase <git-rebase options>
88 # git-ffqrebase finish
89 # git-ffqrebase status [BRANCH]
91 # refs/ffqrebase-prev/BRANCH BRANCH may be refs/...; if not it means
92 # refs/ffqrebase-base/BRANCH refs/heads/BRANCH
93 # zero, one, or both of these may exist
95 # git-debrebase without start, if already started, is willing
96 # to strip pseudomerges provided that they overwrite exactly
98 # xxxx is this right ? what matters is have we pushed
99 # I think in fact the right answer is:
100 # git-debrebase always strips out pseudomerges from its branch
101 # a pseudomerge is put in at the time we want to push
102 # at that time, we make a pseudomerge of the remote tracking
103 # branch (if raw git) or the dgit view (if dgit)
104 # for raw git git-ffqrebase, do want preciseley to record
105 # value of remote tracking branch or our branch, on start, so we
106 # overwrite only things we intend to
107 # the previous pseudomerge check for tags and remote branches ?
111 use Debian::Dgit qw(:DEFAULT :playground);
118 use Getopt::Long qw(:config posix_default gnu_compat bundling);
122 die "bad usage: $m\n";
128 my @cmd = qw(git config -z);
129 push @cmd, qw(--get-all) if wantarray;
131 my $out = cmdoutput @cmd;
132 return split /\0/, $out;
139 my $data = git_cat_file $objid, 'commit';
140 $data =~ m/(?<=\n)\n/ or die "$objid ($data) ?";
144 sub D_UPS () { 0x02; } # upstream files
145 sub D_PAT_ADD () { 0x04; } # debian/patches/ extra patches at end
146 sub D_PAT_OTH () { 0x08; } # debian/patches other changes
147 sub D_DEB_CLOG () { 0x10; } # debian/ (not patches/ or changelog)
148 sub D_DEB_OTH () { 0x20; } # debian/changelog
149 sub DS_DEB () { D_DEB_CLOG | D_DEB_OTH; } # debian/ (not patches/)
151 our $playprefix = 'debrebase';
157 sub in_workarea ($) {
160 my $r = eval { $sub->(); };
161 { local $@; changedir $maindir; }
165 sub fresh_workarea () {
166 $workarea = fresh_playground "$playprefix/work";
167 in_workarea sub { playtree_setup };
170 sub get_differs ($$) {
172 # This resembles quiltify_trees_differ, in dgit, a bit.
173 # But we don't care about modes, or dpkg-source-unrepresentable
174 # changes, and we don't need the plethora of different modes.
175 # Conversely we need to distinguish different kinds of changes to
176 # debian/ and debian/patches/.
181 my ($opts, $limits, $fn) = @_;
182 my @cmd = (@git, qw(diff-tree -z --no-renames));
184 push @cmd, "$_:" foreach $x, $y;
186 my $diffs = cmdoutput @cmd;
187 foreach (split /\0/, $diffs) { $fn->(); }
190 $rundiff->([qw(--name-only)], [], sub {
191 $differs |= $_ eq 'debian' ? DS_DEB : D_UPS;
194 if ($differs & DS_DEB) {
196 $rundiff->([qw(--name-only -r)], [qw(debian)], sub {
198 m{^debian/patches/} ? D_PAT_OTH :
199 $_ eq 'debian/changelog' ? D_DEB_CLOG :
202 die "mysterious debian changes $x..$y"
203 unless $differs & (D_PAT_OTH|DS_DEB);
206 if ($differs & D_PAT_OTH) {
208 $differs &= ~D_PAT_OTH;
210 $differs |= D_PAT_OTH;
211 no warnings qw(exiting); last;
213 $rundiff->([qw(--name-status -r)], [qw(debian/patches/)], sub {
214 no warnings qw(exiting);
215 if (!defined $mode) {
218 die unless s{^debian/patches/}{};
220 if ($mode eq 'A' && !m/\.series$/s) {
222 } elsif ($mode eq 'M' && $_ eq 'series') {
223 my $x_s = git_cat_file "$x:debian/patches/series", 'blob';
224 my $y_s = git_cat_file "$y:debian/patches/series", 'blob';
225 chomp $x_s; $x_s .= "\n";
226 $ok = $x_s eq substr($y_s, 0, length $x_s);
231 $differs |= $ok ? D_PAT_ADD : D_PAT_OTH;
233 die "mysterious debian/patches changes $x..$y"
234 unless $differs & (D_PAT_ADD|D_PAT_OTH);
237 printdebug sprintf "get_differs %s, %s = %#x\n", $x, $y, $differs;
242 sub commit_pr_info ($) {
244 return Data::Dumper->dump([$r], [qw(commit)]);
247 sub calculate_committer_authline () {
248 my $c = cmdoutput @git, qw(commit-tree --no-gpg-sign -m),
249 'DUMMY COMMIT (git-debrebase)', "HEAD:";
250 my ($h,$m) = get_commit $c;
251 $h =~ m/^committer .*$/m or confess "($h) ?";
255 sub rm_subdir_cached ($) {
257 runcmd @git, qw(rm --quiet -rf --cached --ignore-unmatch), $subdir;
260 sub read_tree_subdir ($$) {
261 my ($subdir, $new_tree_object) = @_;
262 rm_subdir_cached $subdir;
263 runcmd @git, qw(read-tree), "--prefix=$subdir/";
266 # classify returns an info hash like this
268 # Hdr => # commit headers, including 1 final newline
269 # Msg => # commit message (so one newline is dropped)
271 # Type => (see below)
273 # Ix => $index # ie 0, 1, 2, ...
275 # Differs => return value from get_differs
277 # IsDggitImport => 'orig' 'tarball' 'unpatched' 'package' (as from dgit)
279 # NewMsg => # commit message, but with any [dgit import ...] edited
280 # # to say "[was: ...]"
291 # has additional entres in classification result
292 # Overwritten = [ subset of Parents ]
293 # Contributor = $the_remaining_Parent
295 # DgitImportUnpatched
296 # has additional entry in classification result
297 # OrigParents = [ subset of Parents ]
299 # BreakwaterUpstreamMerge
300 # has additional entry in classification result
301 # OrigParents = [ subset of Parents ] # singleton list
303 sub parsecommit ($;$) {
304 my ($objid, $p_ref) = @_;
305 # => hash with CommitId Hdr Msg Tree Parents
306 # Parents entries have only Ix CommitId
307 # $p_ref, if provided, must be [] and is used as a base for Parents
312 my ($h,$m) = get_commit $objid;
314 my ($t) = $h =~ m/^tree (\w+)$/m or die $objid;
315 my (@ph) = $h =~ m/^parent (\w+)$/mg;
325 foreach my $ph (@ph) {
339 my $r = parsecommit($objid, \@p);
343 $p->{Differs} => (get_differs $p->{CommitId}, $t),
346 printdebug "classify $objid \$t=$t \@p",
347 (map { sprintf " %s/%#x", $_->{CommitId}, $_->{Differs} } @p),
351 my ($type, @rest) = @_;
352 $r = { %$r, Type => $type, @rest };
354 my $dd = new Data::Dumper [ $r ];
355 Terse $dd 1; Indent $dd 0; Useqq $dd 1;
356 printdebug " = $type ".(Dump $dd)."\n";
362 $r = { %$r, Type => qw(Unknown) };
363 printdebug " ** Unknown\n";
368 my $d = $r->{Parents}[0]{Differs};
369 if ($d == D_PAT_ADD) {
370 return $classify->(qw(AddPatches));
371 } elsif ($d & (D_PAT_ADD|D_PAT_OTH)) {
372 return $unknown->("edits debian/patches");
373 } elsif ($d & DS_DEB and !($d & ~DS_DEB)) {
374 my ($ty,$dummy) = git_cat_file "$ph[0]:debian";
376 if ($d == D_DEB_CLOG) {
377 return $classify->(qw(Changelog));
379 return $classify->(qw(Packaging));
381 } elsif ($ty eq 'missing') {
382 return $classify->(qw(BreakwaterStart));
384 return $unknown->("parent's debian is not a directory");
386 } elsif ($d == D_UPS) {
387 return $classify->(qw(Upstream));
388 } elsif ($d & DS_DEB and $d & D_UPS and !($d & ~(DS_DEB|D_UPS))) {
389 return $classify->(qw(Mixed));
391 return $unknown->("no changes");
393 confess "internal error $objid ?";
397 return $unknown->("origin commit");
400 my @identical = grep { !$_->{Differs} } @p;
401 if (@p == 2 && @identical == 1) {
402 my @overwritten = grep { $_->{Differs} } @p;
403 confess "internal error $objid ?" unless @overwritten==1;
404 return $classify->(qw(Pseudomerge),
405 Overwritten => $overwritten[0],
406 Contributor => $identical[0]);
408 if (@p == 2 && @identical == 2) {
409 my @bytime = nsort_by {
410 my ($ph,$pm) = get_commit $_->{CommitId};
411 $ph =~ m/^committer .* (\d+) [-+]\d+$/m or die "$_->{CommitId} ?";
414 return $classify->(qw(Pseudomerge),
415 SubType => qw(Ambiguous),
416 Overwritten => $bytime[0],
417 Contributor => $bytime[1]);
420 my ($p_h, $p_m) = get_commit $p->{CommitId};
421 $p->{IsOrigin} = $p_h !~ m/^parent \w+$/m;
422 ($p->{IsDgitImport},) = $p_m =~ m/^\[dgit import ([0-9a-z]+) .*\]$/m;
424 my @orig_ps = grep { ($_->{IsDgitImport}//'X') eq 'orig' } @p;
426 if (!(grep { !$_->{IsOrigin} } @p) and
427 (@orig_ps >= @p - 1) and
428 $m2 =~ s{^\[(dgit import unpatched .*)\]$}{[was: $1]}m) {
430 return $classify->(qw(DgitImportUnpatched),
431 OrigParents => \@orig_ps);
434 my ($stype, $series) = git_cat_file "$t:debian/patches/series";
435 my $haspatches = $stype ne 'missing' && $series =~ m/^\s*[^#\n\t ]/m;
437 # How to decide about l/r ordering of breakwater merges ? git
438 # --topo-order prefers to expand 2nd parent first. There's
439 # already an easy rune to look for debian/ history anyway (git log
440 # debian/) so debian breakwater branch should be 1st parent; that
441 # way also there's also an easy rune to look for the upstream
442 # patches (--topo-order).
444 # The above tells us which way *we* will generate them. But we
445 # might encounter ad-hoc breakwater merges generated manually,
446 # which might be the other way around. In principle, in some odd
447 # situations, a breakwater merge might have two identical parents.
448 # In that case we guess which way round it is (ie, which parent
449 # has the upstream history). The order of the 2-iteration loop
450 # controls which guess we make.
452 foreach my $prevbrw (qw(0 1)) {
455 !$p[$prevbrw]{IsOrigin} && # breakwater never starts with an origin
456 !($p[$prevbrw]{Differs} & ~DS_DEB) &&
457 !($p[!$prevbrw]{Differs} & ~D_UPS)) {
458 return $classify->(qw(BreakwaterUpstreamMerge),
459 OrigParents => [ $p[!$prevbrw] ]);
463 # multi-orig upstreams are represented with a breakwater merge
464 # from a single upstream commit which combines the orig tarballs
466 return $unknown->("complex merge");
472 $nogenerate,$report) = @_;
473 # => ($tip, $breakwater_tip)
474 # (or nothing, if $nogenerate)
476 # go through commits backwards
477 # we generate two lists of commits to apply:
478 # breakwater branch and upstream patches
479 my (@brw_cl, @upp_cl, @processed);
486 my ($appendinfo) = @_;
489 $ms .= "\n\n[git-debrebase $appendinfo]\n";
492 my $rewrite_from_here = sub {
493 my $sp_cl = { SpecialMethod => 'StartRewrite' };
494 push @brw_cl, $sp_cl;
495 push @processed, $sp_cl;
500 my $prprdelim = sub { print $report $prdelim if $report; $prdelim=""; };
503 return unless $report;
504 print $report $prdelim, @_;
508 my $bomb = sub { # usage: return $bomb->();
509 print $report " Unprocessable" if $report;
512 return (undef,undef);
514 die "commit $cur: Cannot cope with this commit (d.".
515 (join ' ', map { sprintf "%#x", $_->{Differs} }
516 @{ $cl->{Parents} }). ")";
522 my $build_start = sub {
523 my ($msg, $parent) = @_;
526 no warnings qw(exiting); last;
531 my $ty = $cl->{Type};
532 my $st = $cl->{SubType};
533 $prline->("$cl->{CommitId} $cl->{Type}");
534 $found{$ty. ( defined($st) ? "-$st" : '' )}++;
535 push @processed, $cl;
536 my $p0 = @{ $cl->{Parents} }==1 ? $cl->{Parents}[0]{CommitId} : undef;
537 if ($ty eq 'AddPatches') {
539 $rewrite_from_here->();
541 } elsif ($ty eq 'Packaging' or $ty eq 'Changelog') {
545 } elsif ($ty eq 'BreakwaterStart') {
546 $build_start->('FirstPackaging', $cur);
547 } elsif ($ty eq 'Upstream') {
551 } elsif ($ty eq 'Mixed') {
554 my $cls = { %$cl, $xmsg->("split mixed commit: $wh part") };
557 $queue->(\@brw_cl, "debian");
558 $queue->(\@upp_cl, "upstream");
559 $rewrite_from_here->();
562 } elsif ($ty eq 'Pseudomerge') {
563 my $contrib = $cl->{Contributor}{CommitId};
564 print $report " Contributor=$contrib" if $report;
565 push @pseudomerges, $cl;
566 $rewrite_from_here->();
569 } elsif ($ty eq 'BreakwaterUpstreamMerge') {
570 $build_start->("PreviousBreakwater", $cur);
571 } elsif ($ty eq 'DgitImportUnpatched') {
572 my $pm = $pseudomerges[-1];
574 # To an extent, this is heuristic. Imports don't have
575 # a useful history of the debian/ branch. We assume
576 # that the first pseudomerge after an import has a
577 # useful history of debian/, and ignore the histories
578 # from later pseudomerges. Often the first pseudomerge
579 # will be the dgit import of the upload to the actual
580 # suite intended by the non-dgit NMUer, and later
581 # pseudomerges may represent in-archive copies.
582 my $ovwrs = $pm->{Overwritten};
583 printf $report " PM=%s \@Overwr:%d", $pm, (scalar @$ovwrs)
588 my $ovwr = $ovwrs->[0]{CommitId};
589 printf $report " Overwr=%s", $ovwr if $report;
590 # This import has a tree which is just like a
591 # breakwater tree, but it has the wrong history. It
592 # ought to have the previous breakwater (which the
593 # pseudomerge overwrote) as an ancestor. That will
594 # make the history of the debian/ files correct. As
595 # for the upstream version: either it's the same as
596 # was ovewritten (ie, same as the previous
597 # breakwater), in which case that history is precisely
598 # right; or, otherwise, it was a non-gitish upload of a
599 # new upstream version. We can tell these apart by
600 # looking at the tree of the supposed upstream.
603 SpecialMethod => 'DgitImportDebianUpdate',
604 $xmsg->("convert dgit import: debian changes")
606 my $differs = (get_differs $ovwr, $cl->{Tree});
607 printf $report " Differs=%#x", $differs if $report;
608 if ($differs & D_UPS) {
609 printf $report " D_UPS" if $report;
610 # This will also trigger if a non-dgit git-based NMU
611 # deleted .gitignore (which is a thing that some of
612 # the existing git tools do if the user doesn't
613 # somehow tell them not to). Ah well.
616 SpecialMethod => 'DgitImportUpstreamUpdate',
617 $xmsg->("convert dgit import: upstream changes")
620 $prline->(" Import");
621 $rewrite_from_here->();
622 $upp_limit //= $#upp_cl; # further, deeper, patches discarded
626 # Everything is from this import. This kind of import
627 # is already in valid breakwater format, with the
628 # patches as commits.
629 printf $report " NoPM" if $report;
630 # last thing we processed will have been the first patch,
631 # if there is one; which is fine, so no need to rewrite
632 # on account of this import
633 $build_start->("ImportOrigin", $cur);
641 return if $nogenerate;
643 # Now we build it back up again
649 my $read_tree_debian = sub {
651 read_tree_subdir 'debian', "$treeish:debian";
653 my $read_tree_upstream = sub {
655 runcmd @git, qw(read-tree), $treeish;
656 $read_tree_debian->($build);
659 my $committer_authline = calculate_committer_authline();
661 printdebug "WALK REBUILD $build ".(scalar @processed)."\n";
663 confess "internal error" unless $build eq (pop @processed)->{CommitId};
666 mkdir $rd or $!==EEXIST or die $!;
668 runcmd @git, qw(read-tree), $build;
669 foreach my $cl (qw(Debian), (reverse @brw_cl),
670 { SpecialMethod => 'RecordBreakwaterTip' },
671 qw(Upstream), (reverse @upp_cl)) {
673 $current_method = $cl;
676 my $method = $cl->{SpecialMethod} // $current_method;
677 my @parents = ($build);
678 my $cltree = $cl->{CommitId};
679 printdebug "WALK BUILD ".($cltree//'undef').
680 " $method (rewriting=$rewriting)\n";
681 if ($method eq 'Debian') {
682 $read_tree_debian->($cltree);
683 } elsif ($method eq 'Upstream') {
684 $read_tree_upstream->($cltree);
685 } elsif ($method eq 'StartRewrite') {
688 } elsif ($method eq 'RecordBreakwaterTip') {
689 $breakwater = $build;
691 } elsif ($method eq 'DgitImportDebianUpdate') {
692 $read_tree_debian->($cltree);
693 rm_subdir_cached qw(debian/patches);
694 } elsif ($method eq 'DgitImportUpstreamUpdate') {
695 $read_tree_upstream->($cltree);
696 push @parents, map { $_->{CommitId} } @{ $cl->{OrigParents} };
701 my $procd = (pop @processed) // 'UNDEF';
704 printdebug "WALK REWRITING NOW cl=$cl procd=$procd\n";
707 my $newtree = cmdoutput @git, qw(write-tree);
709 $ch =~ s{^tree .*}{tree $newtree}m or confess "$ch ?";
710 $ch =~ s{^parent .*\n}{}m;
711 $ch =~ s{(?=^author)}{
712 join '', map { "parent $_\n" } @parents
713 }me or confess "$ch ?";
715 $ch =~ s{^committer .*$}{$committer_authline}m
718 my $cf = "$rd/m$rewriting";
719 open CD, ">", $cf or die $!;
720 print CD $ch, "\n", $cl->{Msg} or die $!;
722 my @cmd = (@git, qw(hash-object));
723 push @cmd, qw(-w) if $rewriting;
724 push @cmd, qw(-t commit), $cf;
725 my $newcommit = cmdoutput @cmd;
726 confess "$ch ?" unless $rewriting or $newcommit eq $cl->{CommitId};
731 my $final_check = get_differs $build, $input;
732 die sprintf "internal error %#x %s %s", $final_check, $build, $input
733 if $final_check & ~D_PAT_ADD;
735 return ($build, $breakwater);
738 sub get_head () { return git_rev_parse qw(HEAD); }
740 sub update_head ($$$) {
741 my ($old, $new, $mrest) = @_;
742 runcmd @git, qw(update-ref -m), "debrebase: $mrest", 'HEAD', $new, $old;
745 sub update_head_checkout ($$$) {
746 my ($old, $new, $mrest) = @_;
747 my $symref = git_get_symref();
748 runcmd @git, qw(checkout), $new, qw(.);
749 update_head $old, $new, $mrest;
753 badusage "no arguments to launder allowed" if @ARGV;
754 my $old = get_head();
755 my ($tip,$breakwater) = walk $old;
756 update_head $old, $tip, 'launder';
757 # no tree changes except debian/patches
758 runcmd @git, qw(rm --quiet --ignore-unmatch -rf debian/patches);
759 printf "# breakwater tip\n%s\n", $breakwater;
760 printf "# working tip\n%s\n", $tip;
764 die if ($ARGV[0]//'') =~ m/^-/;
765 badusage "too many arguments to analyse" if @ARGV>1;
768 $old = git_rev_parse $old;
772 my ($dummy,$breakwater) = walk $old, 1,*STDOUT;
773 STDOUT->error and die $!;
776 sub cmd_new_upstream_v0 () {
778 "need NEW-VERSION ORIG-COMMITISH [EXTRA-ORIG-NAME EXTRA-ORIG-COMMITISH...]"
779 unless @ARGV % 2 == 0 and @ARGV >= 2;
780 # tree should be clean and this is not checked
781 # automatically and unconditionally launders before rebasing
782 # if rebase --abort is used, laundering has still been done
784 # parse args - low commitment
785 my $new_version = new Dpkg::Version scalar(shift @ARGV), 1;
786 my $new_upstream_version = $new_version->version();
787 my $new_orig_commitish = git_rev_parse shift @ARGV;
792 New => git_rev_parse shift @ARGV,
794 die unless $xo->{Name} =~ m/^$extra_orig_namepart_re$/;
795 push @extra_origs, $xo;
798 # now we need to investigate the branch this generates the
799 # laundered version but we don't switch to it yet
800 my $old = get_head();
801 my ($laundered_tip,$breakwater) = walk $old;
803 my $breakwater_cl = classify $breakwater;
804 my $old_orig_pi = $breakwater_cl->{OrigParents}[0];
813 print STDERR "upstream not fast forward: $msg\n";
817 # check fast forward, and make new combined-orig commit
818 my $old_orig_ci = parsecommit $old_orig_pi->{CommitId};
819 my $n_old_origs = scalar @{ $old_orig_cp->{Parents} };
820 @{ $n_old_origs } == @extra_origs+1 or
822 "previous breakwater upstream has %d parents".
823 " but new upstream has %d pieces, cannot check ff",
825 (1 + scalar @extra_origs));
828 my @upstream_merge_parents;
830 foreach my $piece_ix (0..$n_old_origs-1) {
831 my $prevpc = $breakwater.'^'.($old_orig_pi->{Ix} + 1);
833 $prevpc .= '^'.($piece_ix + 1);
835 die unless $ git_rev_parse $prevpc;
836 my ($newpc,$newdesc,$pcname);
838 $newpc = $new_orig_commitish;
839 $newdesc = 'new main upstream piece';
841 $newpc = $extra_origs[$piece_ix+1]{New};
842 $pcname = $extra_origs[$piece_ix-1]{Name}
843 $newdesc = "new upstream extra piece \`$pcname";
845 $ffwant->($prevpc, "previous upstream piece ($prevpc)",
846 $newpc, "newdesc ($newpc)");
848 push @upstream_merge_parents, $newpc;
850 my @cmd = @git, qw(read-tree);
851 if (defined $pcname) {
852 push @cmd, "-prefix=$pcname/";
853 runcmd @git, qw(rm --cached -f --ignore-unmatch), $pcname;
859 # index now contains the new upstream
861 die "upstreams not fast forward, stopping".
862 " (xxx should be an override option)";
866 # need to make the upstream subtree merge commit
867 my $us_tree = cmdoutput @git, qw(write-tree);
868 my @cmd = @git, qw(commit-tree), $us_tree;
872 die 'do we want to make ff from previous upstream comb?"';
874 push @cmd, qw(-p), $_ foreach @upstream_merge_parents;
875 push @cmd, qw(-m), "Combine upstreams for $new_upstream_version";
877 "[git-debrebase combine-upstreams . ".
878 (join " ", map { $_->{Name} } @extra_upstreams)."]";
879 my $combined = cmdoutput @cmd;
887 xxx check new orig version is reasonable;
888 xxx decorate new orig version to get new debian version;
891 sub cmd_downstream_rebase_launder_v0 () {
892 badusage "needs 1 argument, the baseline" unless @ARGV==1;
894 $base = git_rev_parse $base;
895 my $old_head = get_head();
896 my $current = $old_head;
899 if ($current eq $base) {
900 $topmost_keep //= $current;
901 print " $current BASE stop\n";
904 my $cl = classify $current;
905 print " $current $cl->{Type}";
907 my $p0 = $cl->{Parents}[0]{CommitId};
909 if ($cl->{Type} eq 'Pseudomerge') {
910 print " ^".($cl->{Contributor}{Ix}+1);
911 $next = $cl->{Contributor}{CommitId};
912 } elsif ($cl->{Type} eq 'AddPatches' or
913 $cl->{Type} eq 'Changelog') {
923 $topmost_keep //= $current;
925 die "to-be stripped changes not on top of the branch\n"
930 if ($topmost_keep eq $old_head) {
933 print "updating to $topmost_keep\n";
935 $old_head, $topmost_keep,
936 'downstream-rebase-launder-v0';
940 GetOptions("D+" => \$debuglevel) or die badusage "bad options\n";
941 initdebug('git-debrebase ');
942 enabledebug if $debuglevel;
944 my $toplevel = cmdoutput @git, qw(rev-parse --show-toplevel);
945 chdir $toplevel or die "chdir $toplevel: $!";
947 $rd = fresh_playground "$playprefix/misc";
949 my $cmd = shift @ARGV;
952 $cmdfn = ${*::}{"cmd_$cmdfn"};
954 $cmdfn or badusage "unknown git-debrebase sub-operation $cmd";