3 # Script helping make fast-forwarding histories while still rebasing
4 # upstream deltas when working on Debian packaging
6 # Copyright (C)2017,2018 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/>.
24 # git-debrebase [<options>] new-upstream-v0 \
25 # <new-version> <orig-commitish> \
26 # [<extra-orig-name> <extra-orig-commitish> ...] \
27 # [<git-rebase options>...]
29 # git-debrebase [<options> --] [<git-rebase options...>]
30 # git-debrebase [<options>] analyse
31 # git-debrebase [<options>] launder # prints breakwater tip etc.
32 # git-debrebase [<options>] downstream-rebase-launder-v0 # experimental
34 # git-debrebase [<options>] gbp2debrebase-v0 \
37 # problems / outstanding questions:
39 # * dgit push with a `3.0 (quilt)' package means doing quilt
40 # fixup. Usually this involves recommitting the whole patch
41 # series, one at a time, with dpkg-source --commit. This is
42 # terribly terribly slow. (Maybe this should be fixed in dgit.)
44 # * dgit push usually needs to (re)make a pseudomerge. The "first"
45 # git-debrebase stripped out the previous pseudomerge and could
46 # have remembeed the HEAD. But it's not quite clear what history
47 # ought to be preserved and what should be discarded. For now
48 # the user will have to tell dgit --overwrite.
50 # To fix this, do we need a new push hook for dgit ?
52 # * Workflow is currently clumsy. Lots of spurious runes to type.
53 # There's not even a guide.
55 # * There are no tests.
57 # * new-upstream-v0 has a terrible UI. You end up with giant
58 # runic command lines.
60 # One consequence of the lack of richness it can need --force in
61 # fairly sensible situations and there is no way to tell it what
62 # you are really trying to do, other than just --force. There
63 # should be an interface with some default branch names.
65 # * There should be a standard convention for the version number,
66 # and unfinalised or not changelog, after new-upstream.
68 # * Handing of multi-orig dgit new-upstream .dsc imports is known to
69 # be broken. They may be not recognised, improperly converted, or
70 # their conversion may be unrecognised.
72 # * Docs need writing and updating. Even README.git-debrebase
73 # describes a design but may not reflect the implementation.
75 # * We need to develop a plausible model that works for derivatives,
76 # who probably want to maintain their stack on top of Debian's.
77 # downstream-rebase-launder-v0 may be a starting point?
81 use Debian::Dgit qw(:DEFAULT :playground);
88 use Getopt::Long qw(:config posix_default gnu_compat bundling);
95 die "bad usage: $m\n";
101 my @cmd = qw(git config -z);
102 push @cmd, qw(--get-all) if wantarray;
104 my $out = cmdoutput @cmd;
105 return split /\0/, $out;
112 my $dd = new Data::Dumper [ $v ];
113 Terse $dd 1; Indent $dd 0; Useqq $dd 1;
119 my $data = (git_cat_file $objid, 'commit');
120 $data =~ m/(?<=\n)\n/ or die "$objid ($data) ?";
124 sub D_UPS () { 0x02; } # upstream files
125 sub D_PAT_ADD () { 0x04; } # debian/patches/ extra patches at end
126 sub D_PAT_OTH () { 0x08; } # debian/patches other changes
127 sub D_DEB_CLOG () { 0x10; } # debian/ (not patches/ or changelog)
128 sub D_DEB_OTH () { 0x20; } # debian/changelog
129 sub DS_DEB () { D_DEB_CLOG | D_DEB_OTH; } # debian/ (not patches/)
131 our $playprefix = 'debrebase';
137 sub in_workarea ($) {
140 my $r = eval { $sub->(); };
141 { local $@; changedir $maindir; }
145 sub fresh_workarea () {
146 $workarea = fresh_playground "$playprefix/work";
147 in_workarea sub { playtree_setup };
150 sub get_differs ($$) {
152 # This resembles quiltify_trees_differ, in dgit, a bit.
153 # But we don't care about modes, or dpkg-source-unrepresentable
154 # changes, and we don't need the plethora of different modes.
155 # Conversely we need to distinguish different kinds of changes to
156 # debian/ and debian/patches/.
161 my ($opts, $limits, $fn) = @_;
162 my @cmd = (@git, qw(diff-tree -z --no-renames));
164 push @cmd, "$_:" foreach $x, $y;
165 push @cmd, '--', @$limits;
166 my $diffs = cmdoutput @cmd;
167 foreach (split /\0/, $diffs) { $fn->(); }
170 $rundiff->([qw(--name-only)], [], sub {
171 $differs |= $_ eq 'debian' ? DS_DEB : D_UPS;
174 if ($differs & DS_DEB) {
176 $rundiff->([qw(--name-only -r)], [qw(debian)], sub {
178 m{^debian/patches/} ? D_PAT_OTH :
179 $_ eq 'debian/changelog' ? D_DEB_CLOG :
182 die "mysterious debian changes $x..$y"
183 unless $differs & (D_PAT_OTH|DS_DEB);
186 if ($differs & D_PAT_OTH) {
188 $differs &= ~D_PAT_OTH;
190 $differs |= D_PAT_OTH;
191 no warnings qw(exiting); last;
193 $rundiff->([qw(--name-status -r)], [qw(debian/patches/)], sub {
194 no warnings qw(exiting);
195 if (!defined $mode) {
198 die unless s{^debian/patches/}{};
200 if ($mode eq 'A' && !m/\.series$/s) {
202 } elsif ($mode eq 'M' && $_ eq 'series') {
203 my $x_s = (git_cat_file "$x:debian/patches/series", 'blob');
204 my $y_s = (git_cat_file "$y:debian/patches/series", 'blob');
205 chomp $x_s; $x_s .= "\n";
206 $ok = $x_s eq substr($y_s, 0, length $x_s);
211 $differs |= $ok ? D_PAT_ADD : D_PAT_OTH;
213 die "mysterious debian/patches changes $x..$y"
214 unless $differs & (D_PAT_ADD|D_PAT_OTH);
217 printdebug sprintf "get_differs %s, %s = %#x\n", $x, $y, $differs;
222 sub commit_pr_info ($) {
224 return Data::Dumper->dump([$r], [qw(commit)]);
227 sub calculate_committer_authline () {
228 my $c = cmdoutput @git, qw(commit-tree --no-gpg-sign -m),
229 'DUMMY COMMIT (git-debrebase)', "HEAD:";
230 my ($h,$m) = get_commit $c;
231 $h =~ m/^committer .*$/m or confess "($h) ?";
235 sub rm_subdir_cached ($) {
237 runcmd @git, qw(rm --quiet -rf --cached --ignore-unmatch), $subdir;
240 sub read_tree_subdir ($$) {
241 my ($subdir, $new_tree_object) = @_;
242 rm_subdir_cached $subdir;
243 runcmd @git, qw(read-tree), "--prefix=$subdir/", $new_tree_object;
246 sub make_commit ($$) {
247 my ($parents, $message_paras) = @_;
248 my $tree = cmdoutput @git, qw(write-tree);
249 my @cmd = (@git, qw(commit-tree), $tree);
250 push @cmd, qw(-p), $_ foreach @$parents;
251 push @cmd, qw(-m), $_ foreach @$message_paras;
252 return cmdoutput @cmd;
259 print STDERR "git-debrebase: safety catch tripped: $msg\n";
261 sub fproblems_maybe_bail () {
265 "safety catch trips (%d) overriden by --force\n",
269 "safety catch trips (%d) (you could --force)",
275 # classify returns an info hash like this
277 # Hdr => # commit headers, including 1 final newline
278 # Msg => # commit message (so one newline is dropped)
280 # Type => (see below)
282 # Ix => $index # ie 0, 1, 2, ...
284 # Differs => return value from get_differs
286 # IsDggitImport => 'orig' 'tarball' 'unpatched' 'package' (as from dgit)
288 # NewMsg => # commit message, but with any [dgit import ...] edited
289 # # to say "[was: ...]"
300 # has additional entres in classification result
301 # Overwritten = [ subset of Parents ]
302 # Contributor = $the_remaining_Parent
304 # DgitImportUnpatched
305 # has additional entry in classification result
306 # OrigParents = [ subset of Parents ]
308 # BreakwaterUpstreamMerge
309 # has additional entry in classification result
310 # OrigParents = [ subset of Parents ] # singleton list
312 sub parsecommit ($;$) {
313 my ($objid, $p_ref) = @_;
314 # => hash with CommitId Hdr Msg Tree Parents
315 # Parents entries have only Ix CommitId
316 # $p_ref, if provided, must be [] and is used as a base for Parents
321 my ($h,$m) = get_commit $objid;
323 my ($t) = $h =~ m/^tree (\w+)$/m or die $objid;
324 my (@ph) = $h =~ m/^parent (\w+)$/mg;
334 foreach my $ph (@ph) {
336 Ix => scalar @$p_ref,
348 my $r = parsecommit($objid, \@p);
352 $p->{Differs} = (get_differs $p->{CommitId}, $t),
355 printdebug "classify $objid \$t=$t \@p",
356 (map { sprintf " %s/%#x", $_->{CommitId}, $_->{Differs} } @p),
360 my ($type, @rest) = @_;
361 $r = { %$r, Type => $type, @rest };
363 printdebug " = $type ".(dd $r)."\n";
369 $r = { %$r, Type => qw(Unknown) };
370 printdebug " ** Unknown\n";
375 my $d = $r->{Parents}[0]{Differs};
376 if ($d == D_PAT_ADD) {
377 return $classify->(qw(AddPatches));
378 } elsif ($d & (D_PAT_ADD|D_PAT_OTH)) {
379 return $unknown->("edits debian/patches");
380 } elsif ($d & DS_DEB and !($d & ~DS_DEB)) {
381 my ($ty,$dummy) = git_cat_file "$p[0]{CommitId}:debian";
383 if ($d == D_DEB_CLOG) {
384 return $classify->(qw(Changelog));
386 return $classify->(qw(Packaging));
388 } elsif ($ty eq 'missing') {
389 return $classify->(qw(BreakwaterStart));
391 return $unknown->("parent's debian is not a directory");
393 } elsif ($d == D_UPS) {
394 return $classify->(qw(Upstream));
395 } elsif ($d & DS_DEB and $d & D_UPS and !($d & ~(DS_DEB|D_UPS))) {
396 return $classify->(qw(Mixed));
398 return $unknown->("no changes");
400 confess "internal error $objid ?";
404 return $unknown->("origin commit");
407 my @identical = grep { !$_->{Differs} } @p;
408 if (@p == 2 && @identical == 1) {
409 my @overwritten = grep { $_->{Differs} } @p;
410 confess "internal error $objid ?" unless @overwritten==1;
411 return $classify->(qw(Pseudomerge),
412 Overwritten => $overwritten[0],
413 Contributor => $identical[0]);
415 if (@p == 2 && @identical == 2) {
416 my @bytime = nsort_by {
417 my ($ph,$pm) = get_commit $_->{CommitId};
418 $ph =~ m/^committer .* (\d+) [-+]\d+$/m or die "$_->{CommitId} ?";
421 return $classify->(qw(Pseudomerge),
422 SubType => qw(Ambiguous),
423 Overwritten => $bytime[0],
424 Contributor => $bytime[1]);
427 my ($p_h, $p_m) = get_commit $p->{CommitId};
428 $p->{IsOrigin} = $p_h !~ m/^parent \w+$/m;
429 ($p->{IsDgitImport},) = $p_m =~ m/^\[dgit import ([0-9a-z]+) .*\]$/m;
431 my @orig_ps = grep { ($_->{IsDgitImport}//'X') eq 'orig' } @p;
433 if (!(grep { !$_->{IsOrigin} } @p) and
434 (@orig_ps >= @p - 1) and
435 $m2 =~ s{^\[(dgit import unpatched .*)\]$}{[was: $1]}m) {
437 return $classify->(qw(DgitImportUnpatched),
438 OrigParents => \@orig_ps);
441 my ($stype, $series) = git_cat_file "$t:debian/patches/series";
442 my $haspatches = $stype ne 'missing' && $series =~ m/^\s*[^#\n\t ]/m;
444 # How to decide about l/r ordering of breakwater merges ? git
445 # --topo-order prefers to expand 2nd parent first. There's
446 # already an easy rune to look for debian/ history anyway (git log
447 # debian/) so debian breakwater branch should be 1st parent; that
448 # way also there's also an easy rune to look for the upstream
449 # patches (--topo-order).
451 # The above tells us which way *we* will generate them. But we
452 # might encounter ad-hoc breakwater merges generated manually,
453 # which might be the other way around. In principle, in some odd
454 # situations, a breakwater merge might have two identical parents.
455 # In that case we guess which way round it is (ie, which parent
456 # has the upstream history). The order of the 2-iteration loop
457 # controls which guess we make.
459 foreach my $prevbrw (qw(0 1)) {
462 !$p[$prevbrw]{IsOrigin} && # breakwater never starts with an origin
463 !($p[!$prevbrw]{Differs} & ~DS_DEB) && # no non-debian changess
464 !($p[$prevbrw]{Differs} & ~D_UPS)) { # no non-upstream changes
465 return $classify->(qw(BreakwaterUpstreamMerge),
466 OrigParents => [ $p[!$prevbrw] ]);
470 # multi-orig upstreams are represented with a breakwater merge
471 # from a single upstream commit which combines the orig tarballs
473 return $unknown->("complex merge");
479 $nogenerate,$report) = @_;
480 # => ($tip, $breakwater_tip, $last_upstream_merge_in_breakwater)
481 # (or nothing, if $nogenerate)
483 printdebug "*** WALK $input ".($nogenerate//0)." ".($report//'-')."\n";
485 # go through commits backwards
486 # we generate two lists of commits to apply:
487 # breakwater branch and upstream patches
488 my (@brw_cl, @upp_cl, @processed);
495 my ($prose, $info) = @_;
499 $ms .= "\n\n[git-debrebase$info: $prose]\n";
502 my $rewrite_from_here = sub {
503 my $sp_cl = { SpecialMethod => 'StartRewrite' };
504 push @brw_cl, $sp_cl;
505 push @processed, $sp_cl;
510 my $prprdelim = sub { print $report $prdelim if $report; $prdelim=""; };
513 return unless $report;
514 print $report $prdelim, @_;
518 my $bomb = sub { # usage: return $bomb->();
519 print $report " Unprocessable" if $report;
522 return (undef,undef);
524 die "commit $cur: Cannot cope with this commit (d.".
525 (join ' ', map { sprintf "%#x", $_->{Differs} }
526 @{ $cl->{Parents} }). ")";
532 my $build_start = sub {
533 my ($msg, $parent) = @_;
536 no warnings qw(exiting); last;
539 my $last_upstream_update;
543 my $ty = $cl->{Type};
544 my $st = $cl->{SubType};
545 $prline->("$cl->{CommitId} $cl->{Type}");
546 $found{$ty. ( defined($st) ? "-$st" : '' )}++;
547 push @processed, $cl;
548 my $p0 = @{ $cl->{Parents} }==1 ? $cl->{Parents}[0]{CommitId} : undef;
549 if ($ty eq 'AddPatches') {
551 $rewrite_from_here->();
553 } elsif ($ty eq 'Packaging' or $ty eq 'Changelog') {
557 } elsif ($ty eq 'BreakwaterStart') {
558 $last_upstream_update = $cur;
559 $build_start->('FirstPackaging', $cur);
560 } elsif ($ty eq 'Upstream') {
564 } elsif ($ty eq 'Mixed') {
567 my $cls = { %$cl, $xmsg->("split mixed commit: $wh part") };
570 $queue->(\@brw_cl, "debian");
571 $queue->(\@upp_cl, "upstream");
572 $rewrite_from_here->();
575 } elsif ($ty eq 'Pseudomerge') {
576 my $contrib = $cl->{Contributor}{CommitId};
577 print $report " Contributor=$contrib" if $report;
578 push @pseudomerges, $cl;
579 $rewrite_from_here->();
582 } elsif ($ty eq 'BreakwaterUpstreamMerge') {
583 $last_upstream_update = $cur;
584 $build_start->("PreviousBreakwater", $cur);
585 } elsif ($ty eq 'DgitImportUnpatched') {
586 my $pm = $pseudomerges[-1];
588 # To an extent, this is heuristic. Imports don't have
589 # a useful history of the debian/ branch. We assume
590 # that the first pseudomerge after an import has a
591 # useful history of debian/, and ignore the histories
592 # from later pseudomerges. Often the first pseudomerge
593 # will be the dgit import of the upload to the actual
594 # suite intended by the non-dgit NMUer, and later
595 # pseudomerges may represent in-archive copies.
596 my $ovwrs = $pm->{Overwritten};
597 printf $report " PM=%s \@Overwr:%d", $pm, (scalar @$ovwrs)
600 printdebug "*** WALK BOMB DgitImportUnpatched\n";
603 my $ovwr = $ovwrs->[0]{CommitId};
604 printf $report " Overwr=%s", $ovwr if $report;
605 # This import has a tree which is just like a
606 # breakwater tree, but it has the wrong history. It
607 # ought to have the previous breakwater (which the
608 # pseudomerge overwrote) as an ancestor. That will
609 # make the history of the debian/ files correct. As
610 # for the upstream version: either it's the same as
611 # was ovewritten (ie, same as the previous
612 # breakwater), in which case that history is precisely
613 # right; or, otherwise, it was a non-gitish upload of a
614 # new upstream version. We can tell these apart by
615 # looking at the tree of the supposed upstream.
618 SpecialMethod => 'DgitImportDebianUpdate',
619 $xmsg->("convert dgit import: debian changes")
621 my $differs = (get_differs $ovwr, $cl->{Tree});
622 printf $report " Differs=%#x", $differs if $report;
623 if ($differs & D_UPS) {
624 printf $report " D_UPS" if $report;
625 # This will also trigger if a non-dgit git-based NMU
626 # deleted .gitignore (which is a thing that some of
627 # the existing git tools do if the user doesn't
628 # somehow tell them not to). Ah well.
631 SpecialMethod => 'DgitImportUpstreamUpdate',
632 $xmsg->("convert dgit import: upstream changes",
636 $prline->(" Import");
637 $rewrite_from_here->();
638 $upp_limit //= $#upp_cl; # further, deeper, patches discarded
639 die 'BUG $upp_limit is not used anywhere?';
643 # Everything is from this import. This kind of import
644 # is already in valid breakwater format, with the
645 # patches as commits.
646 printf $report " NoPM" if $report;
647 # last thing we processed will have been the first patch,
648 # if there is one; which is fine, so no need to rewrite
649 # on account of this import
650 $build_start->("ImportOrigin", $cur);
654 printdebug "*** WALK BOMB unrecognised\n";
660 printdebug "*** WALK prep done cur=$cur".
661 " brw $#brw_cl upp $#upp_cl proc $#processed pm $#pseudomerges\n";
663 return if $nogenerate;
665 # Now we build it back up again
671 my $read_tree_debian = sub {
673 read_tree_subdir 'debian', "$treeish:debian";
674 rm_subdir_cached 'debian/patches';
676 my $read_tree_upstream = sub {
678 runcmd @git, qw(read-tree), $treeish;
679 $read_tree_debian->($build);
682 my $committer_authline = calculate_committer_authline();
684 printdebug "WALK REBUILD $build ".(scalar @processed)."\n";
686 confess "internal error" unless $build eq (pop @processed)->{CommitId};
689 mkdir $rd or $!==EEXIST or die $!;
691 runcmd @git, qw(read-tree), $build;
692 foreach my $cl (qw(Debian), (reverse @brw_cl),
693 { SpecialMethod => 'RecordBreakwaterTip' },
694 qw(Upstream), (reverse @upp_cl)) {
696 $current_method = $cl;
699 my $method = $cl->{SpecialMethod} // $current_method;
700 my @parents = ($build);
701 my $cltree = $cl->{CommitId};
702 printdebug "WALK BUILD ".($cltree//'undef').
703 " $method (rewriting=$rewriting)\n";
704 if ($method eq 'Debian') {
705 $read_tree_debian->($cltree);
706 } elsif ($method eq 'Upstream') {
707 $read_tree_upstream->($cltree);
708 } elsif ($method eq 'StartRewrite') {
711 } elsif ($method eq 'RecordBreakwaterTip') {
712 $breakwater = $build;
714 } elsif ($method eq 'DgitImportDebianUpdate') {
715 $read_tree_debian->($cltree);
716 rm_subdir_cached qw(debian/patches);
717 } elsif ($method eq 'DgitImportUpstreamUpdate') {
718 $read_tree_upstream->($cltree);
719 push @parents, map { $_->{CommitId} } @{ $cl->{OrigParents} };
724 my $procd = (pop @processed) // 'UNDEF';
727 printdebug "WALK REWRITING NOW cl=$cl procd=$procd\n";
730 my $newtree = cmdoutput @git, qw(write-tree);
732 $ch =~ s{^tree .*}{tree $newtree}m or confess "$ch ?";
733 $ch =~ s{^parent .*\n}{}m;
734 $ch =~ s{(?=^author)}{
735 join '', map { "parent $_\n" } @parents
736 }me or confess "$ch ?";
738 $ch =~ s{^committer .*$}{$committer_authline}m
741 my $cf = "$rd/m$rewriting";
742 open CD, ">", $cf or die $!;
743 print CD $ch, "\n", $cl->{Msg} or die $!;
745 my @cmd = (@git, qw(hash-object));
746 push @cmd, qw(-w) if $rewriting;
747 push @cmd, qw(-t commit), $cf;
748 my $newcommit = cmdoutput @cmd;
749 confess "$ch ?" unless $rewriting or $newcommit eq $cl->{CommitId};
751 if (grep { $method eq $_ } qw(DgitImportUpstreamUpdate)) {
752 $last_upstream_update = $cur;
757 my $final_check = get_differs $build, $input;
758 die sprintf "internal error %#x %s %s", $final_check, $build, $input
759 if $final_check & ~D_PAT_ADD;
761 my @r = ($build, $breakwater, $last_upstream_update);
762 printdebug "*** WALK RETURN @r\n";
766 sub get_head () { return git_rev_parse qw(HEAD); }
768 sub update_head ($$$) {
769 my ($old, $new, $mrest) = @_;
770 runcmd @git, qw(update-ref -m), "debrebase: $mrest", 'HEAD', $new, $old;
773 sub update_head_checkout ($$$) {
774 my ($old, $new, $mrest) = @_;
775 update_head $old, $new, $mrest;
776 runcmd @git, qw(reset --hard);
779 sub update_head_postlaunder ($$$) {
780 my ($old, $tip, $reflogmsg) = @_;
781 return if $tip eq $old;
782 print "git-debrebase: laundered (head was $old)\n";
783 update_head $old, $tip, $reflogmsg;
784 # no tree changes except debian/patches
785 runcmd @git, qw(rm --quiet --ignore-unmatch -rf debian/patches);
789 badusage "no arguments to launder allowed" if @ARGV;
790 my $old = get_head();
791 my ($tip,$breakwater,$last_upstream_merge) = walk $old;
792 update_head_postlaunder $old, $tip, 'launder';
793 printf "# breakwater tip\n%s\n", $breakwater;
794 printf "# working tip\n%s\n", $tip;
795 printf "# last upstream merge\n%s\n", $last_upstream_merge;
798 sub defaultcmd_rebase () {
799 my $old = get_head();
800 my ($tip,$breakwater) = walk $old;
801 update_head_postlaunder $old, $tip, 'launder for rebase';
802 @ARGV = qw(-i) unless @ARGV; # make configurable
803 runcmd @git, qw(rebase), @ARGV, $breakwater;
807 die if ($ARGV[0]//'') =~ m/^-/;
808 badusage "too many arguments to analyse" if @ARGV>1;
811 $old = git_rev_parse $old;
815 my ($dummy,$breakwater) = walk $old, 1,*STDOUT;
816 STDOUT->error and die $!;
819 sub cmd_new_upstream_v0 () {
820 # tree should be clean and this is not checked
821 # automatically and unconditionally launders before rebasing
822 # if rebase --abort is used, laundering has still been done
826 badusage "need NEW-VERSION UPS-COMMITTISH" unless @ARGV >= 2;
828 # parse args - low commitment
829 my $new_version = (new Dpkg::Version scalar(shift @ARGV), check => 1);
830 my $new_upstream_version = $new_version->version();
832 my $new_upstream = git_rev_parse shift @ARGV;
835 my ($n, @x) = @_; # may be ''
836 my $pc = $pieces{$n} //= {
838 Desc => ($n ? "upstream piece \`$n'" : "upstream (main piece"),
840 while (my $k = shift @x) { $pc->{$k} = shift @x; }
846 my ($n, @x) = @_; # may be ''
847 my $pc = $piece->($n, @x, NewIx => (scalar @newpieces));
848 push @newpieces, $pc;
853 New => $new_upstream,
855 while (@ARGV && $ARGV[0] !~ m{^-}) {
858 badusage "for each EXTRA-UPS-NAME need EXTRA-UPS-COMMITISH"
859 unless @ARGV && $ARGV[0] !~ m{^-};
861 my $c = git_rev_parse shift @ARGV;
862 die unless $n =~ m/^$extra_orig_namepart_re$/;
863 $newpiece->($n, New => $c);
866 # now we need to investigate the branch this generates the
867 # laundered version but we don't switch to it yet
868 my $old_head = get_head();
869 my ($old_laundered_tip,$old_bw,$old_upstream_update) = walk $old_head;
871 my $old_bw_cl = classify $old_bw;
872 my $old_upstream_update_cl = classify $old_upstream_update;
873 confess unless $old_upstream_update_cl->{OrigParents};
874 my $old_upstream = parsecommit
875 $old_upstream_update_cl->{OrigParents}[0]{CommitId};
877 $piece->('', Old => $old_upstream->{CommitId});
879 if ($old_upstream->{Msg} =~ m{^\[git-debrebase }m) {
880 if ($old_upstream->{Msg} =~
881 m{^\[git-debrebase upstream-combine \.((?: $extra_orig_namepart_re)+)\:.*\]$}m
883 my @oldpieces = ('', split / /, $1);
884 my $parentix = -1 + scalar @{ $old_upstream->{Parents} };
885 foreach my $i (0..$#oldpieces) {
886 my $n = $oldpieces[$i];
887 $piece->($n, Old => $old_upstream->{CommitId}.'^'.$parentix);
890 fproblem "previous upstream $old_upstream->{CommitId} is from".
891 " git-debrebase but not an \`upstream-combine' commit";
895 foreach my $pc (values %pieces) {
897 fproblem "introducing upstream piece \`$pc->{Name}'";
898 } elsif (!$pc->{New}) {
899 fproblem "dropping upstream piece \`$pc->{Name}'";
900 } elsif (!is_fast_fwd $pc->{Old}, $pc->{New}) {
901 fproblem "not fast forward: $pc->{Name} $pc->{Old}..$pc->{New}";
905 printdebug "%pieces = ", (dd \%pieces), "\n";
906 printdebug "\@newpieces = ", (dd \@newpieces), "\n";
908 fproblems_maybe_bail();
914 my @upstream_merge_parents;
917 push @upstream_merge_parents, $old_upstream->{CommitId};
920 foreach my $pc (@newpieces) { # always has '' first
922 read_tree_subdir $pc->{Name}, $pc->{New};
924 runcmd @git, qw(read-tree), $pc->{New};
926 push @upstream_merge_parents, $pc->{New};
929 # index now contains the new upstream
931 if (@newpieces > 1) {
932 # need to make the upstream subtree merge commit
933 $new_upstream = make_commit \@upstream_merge_parents,
934 [ "Combine upstreams for $new_upstream_version",
935 ("[git-debrebase upstream-combine . ".
936 (join " ", map { $_->{Name} } @newpieces[1..$#newpieces]).
941 # $new_upstream is either the single upstream commit, or the
942 # combined commit we just made. Either way it will be the
943 # "upstream" parent of the breakwater special merge.
945 read_tree_subdir 'debian', "$old_bw:debian";
947 # index now contains the breakwater merge contents
948 $new_bw = make_commit [ $old_bw, $new_upstream ],
949 [ "Update to upstream $new_upstream_version",
950 "[git-debrebase breakwater: new upstream $new_upstream_version, merge]",
953 # Now we have to add a changelog stanza so the Debian version
955 die if unlink "debian";
956 die $! unless $!==ENOENT or $!==ENOTEMPTY;
957 unlink "debian/changelog" or $!==ENOENT or die $!;
958 mkdir "debian" or die $!;
959 open CN, ">", "debian/changelog" or die $!;
960 my $oldclog = git_cat_file ":debian/changelog";
961 $oldclog =~ m/^($package_re) \(\S+\) / or
962 fail "cannot parse old changelog to get package name";
964 print CN <<END, $oldclog or die $!;
965 $p ($new_version) UNRELEASED; urgency=medium
967 * Update to new upstream version $new_upstream_version.
973 runcmd @git, qw(update-index --add --replace), 'debian/changelog';
975 # Now we have the final new breakwater branch in the index
976 $new_bw = make_commit [ $new_bw ],
977 [ "Update changelog for new upstream $new_upstream_version",
978 "[git-debrebase: new upstream $new_upstream_version, changelog]",
982 # we have constructed the new breakwater. we now need to commit to
983 # the laundering output, because git-rebase can't easily be made
984 # to make a replay list which is based on some other branch
986 update_head_postlaunder $old_head, $old_laundered_tip,
987 'launder for new upstream';
989 my @cmd = (@git, qw(rebase --onto), $new_bw, $old_bw, @ARGV);
991 # now it's for the user to sort out
994 sub cmd_gbp2debrebase () {
995 badusage "needs 1 optional argument, the upstream" unless @ARGV<=1;
996 my ($upstream_spec) = @ARGV;
997 $upstream_spec //= 'refs/heads/upstream';
998 my $upstream = git_rev_parse $upstream_spec;
999 my $old_head = get_head();
1001 my $upsdiff = get_differs $upstream, $old_head;
1002 if ($upsdiff & D_UPS) {
1003 runcmd @git, qw(--no-pager diff),
1004 $upstream, $old_head,
1005 qw( -- :!/debian :/);
1006 fail "upstream ($upstream_spec) and HEAD are not identical in upstream files";
1009 if (!is_fast_fwd $upstream, $old_head) {
1010 fproblem "upstream ($upstream) is not an ancestor of HEAD";
1012 my $wrong = cmdoutput
1013 (@git, qw(rev-list --ancestry-path), "$upstream..HEAD",
1014 qw(-- :/ :!/debian));
1015 if (length $wrong) {
1016 fproblem "history between upstream ($upstream) and HEAD contains direct changes to upstream files - are you sure this is a gbp (patches-unapplied) branch?";
1017 print STDERR "list expected changes with: git log --stat --ancestry-path $upstream_spec..HEAD -- :/ ':!/debian'\n";
1021 if ((git_cat_file "$upstream:debian")[0] ne 'missing') {
1022 fproblem "upstream ($upstream) contains debian/ directory";
1025 fproblems_maybe_bail();
1031 runcmd @git, qw(checkout -q -b gdr-internal), $old_head;
1032 # make a branch out of the patch queue - we'll want this in a mo
1033 runcmd qw(gbp pq import);
1034 # strip the patches out
1035 runcmd @git, qw(checkout -q gdr-internal~0);
1036 rm_subdir_cached 'debian/patches';
1037 $work = make_commit ['HEAD'], [
1038 'git-debrebase import: drop patch queue',
1039 'Delete debian/patches, as part of converting to git-debrebase format.',
1040 '[git-debrebase: gbp2debrebase, drop patches]'
1042 # make the breakwater pseudomerge
1043 # the tree is already exactly right
1044 $work = make_commit [$work, $upstream], [
1045 'git-debrebase import: declare upstream',
1046 'First breakwater merge.',
1047 '[git-debrebase breakwater: declare upstream]'
1050 # rebase the patch queue onto the new breakwater
1051 runcmd @git, qw(reset --quiet --hard patch-queue/gdr-internal);
1052 runcmd @git, qw(rebase --quiet --onto), $work, qw(gdr-internal);
1056 update_head_checkout $old_head, $work, 'gbp2debrebase';
1059 sub cmd_downstream_rebase_launder_v0 () {
1060 badusage "needs 1 argument, the baseline" unless @ARGV==1;
1062 $base = git_rev_parse $base;
1063 my $old_head = get_head();
1064 my $current = $old_head;
1067 if ($current eq $base) {
1068 $topmost_keep //= $current;
1069 print " $current BASE stop\n";
1072 my $cl = classify $current;
1073 print " $current $cl->{Type}";
1075 my $p0 = $cl->{Parents}[0]{CommitId};
1077 if ($cl->{Type} eq 'Pseudomerge') {
1078 print " ^".($cl->{Contributor}{Ix}+1);
1079 $next = $cl->{Contributor}{CommitId};
1080 } elsif ($cl->{Type} eq 'AddPatches' or
1081 $cl->{Type} eq 'Changelog') {
1091 $topmost_keep //= $current;
1093 die "to-be stripped changes not on top of the branch\n"
1098 if ($topmost_keep eq $old_head) {
1099 print "unchanged\n";
1101 print "updating to $topmost_keep\n";
1102 update_head_checkout
1103 $old_head, $topmost_keep,
1104 'downstream-rebase-launder-v0';
1108 GetOptions("D+" => \$debuglevel,
1109 'force!') or die badusage "bad options\n";
1110 initdebug('git-debrebase ');
1111 enabledebug if $debuglevel;
1113 my $toplevel = cmdoutput @git, qw(rev-parse --show-toplevel);
1114 chdir $toplevel or die "chdir $toplevel: $!";
1116 $rd = fresh_playground "$playprefix/misc";
1118 if (!@ARGV || $ARGV[0] =~ m{^-}) {
1119 defaultcmd_rebase();
1121 my $cmd = shift @ARGV;
1124 $cmdfn = ${*::}{"cmd_$cmdfn"};
1126 $cmdfn or badusage "unknown git-debrebase sub-operation $cmd";