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)",
274 sub any_fproblems () {
278 # classify returns an info hash like this
280 # Hdr => # commit headers, including 1 final newline
281 # Msg => # commit message (so one newline is dropped)
283 # Type => (see below)
285 # Ix => $index # ie 0, 1, 2, ...
287 # Differs => return value from get_differs
289 # IsDggitImport => 'orig' 'tarball' 'unpatched' 'package' (as from dgit)
291 # NewMsg => # commit message, but with any [dgit import ...] edited
292 # # to say "[was: ...]"
303 # has additional entres in classification result
304 # Overwritten = [ subset of Parents ]
305 # Contributor = $the_remaining_Parent
307 # DgitImportUnpatched
308 # has additional entry in classification result
309 # OrigParents = [ subset of Parents ]
311 # BreakwaterUpstreamMerge
312 # has additional entry in classification result
313 # OrigParents = [ subset of Parents ] # singleton list
315 sub parsecommit ($;$) {
316 my ($objid, $p_ref) = @_;
317 # => hash with CommitId Hdr Msg Tree Parents
318 # Parents entries have only Ix CommitId
319 # $p_ref, if provided, must be [] and is used as a base for Parents
324 my ($h,$m) = get_commit $objid;
326 my ($t) = $h =~ m/^tree (\w+)$/m or die $objid;
327 my (@ph) = $h =~ m/^parent (\w+)$/mg;
337 foreach my $ph (@ph) {
339 Ix => scalar @$p_ref,
351 my $r = parsecommit($objid, \@p);
355 $p->{Differs} = (get_differs $p->{CommitId}, $t),
358 printdebug "classify $objid \$t=$t \@p",
359 (map { sprintf " %s/%#x", $_->{CommitId}, $_->{Differs} } @p),
363 my ($type, @rest) = @_;
364 $r = { %$r, Type => $type, @rest };
366 printdebug " = $type ".(dd $r)."\n";
372 $r = { %$r, Type => qw(Unknown) };
373 printdebug " ** Unknown\n";
377 my $claims_to_be_breakwater =
378 $r->{Msg} =~ m{^\[git-debrebase breakwater.*\]$}m;
381 if ($claims_to_be_breakwater) {
382 return $unknown->("single-parent git-debrebase breakwater \`merge'");
384 my $d = $r->{Parents}[0]{Differs};
385 if ($d == D_PAT_ADD) {
386 return $classify->(qw(AddPatches));
387 } elsif ($d & (D_PAT_ADD|D_PAT_OTH)) {
388 return $unknown->("edits debian/patches");
389 } elsif ($d & DS_DEB and !($d & ~DS_DEB)) {
390 my ($ty,$dummy) = git_cat_file "$p[0]{CommitId}:debian";
392 if ($d == D_DEB_CLOG) {
393 return $classify->(qw(Changelog));
395 return $classify->(qw(Packaging));
397 } elsif ($ty eq 'missing') {
398 return $classify->(qw(BreakwaterStart));
400 return $unknown->("parent's debian is not a directory");
402 } elsif ($d == D_UPS) {
403 return $classify->(qw(Upstream));
404 } elsif ($d & DS_DEB and $d & D_UPS and !($d & ~(DS_DEB|D_UPS))) {
405 return $classify->(qw(Mixed));
407 return $unknown->("no changes");
409 confess "internal error $objid ?";
413 return $unknown->("origin commit");
416 my @identical = grep { !$_->{Differs} } @p;
417 if (@p == 2 && @identical == 1 && !$claims_to_be_breakwater
418 # breakwater merges can look like pseudomerges, if they are
419 # "declare" commits (ie, there are no upstream changes)
421 my @overwritten = grep { $_->{Differs} } @p;
422 confess "internal error $objid ?" unless @overwritten==1;
423 return $classify->(qw(Pseudomerge),
424 Overwritten => $overwritten[0],
425 Contributor => $identical[0]);
427 if (@p == 2 && @identical == 2) {
428 my @bytime = nsort_by {
429 my ($ph,$pm) = get_commit $_->{CommitId};
430 $ph =~ m/^committer .* (\d+) [-+]\d+$/m or die "$_->{CommitId} ?";
433 return $classify->(qw(Pseudomerge),
434 SubType => qw(Ambiguous),
435 Overwritten => $bytime[0],
436 Contributor => $bytime[1]);
439 my ($p_h, $p_m) = get_commit $p->{CommitId};
440 $p->{IsOrigin} = $p_h !~ m/^parent \w+$/m;
441 ($p->{IsDgitImport},) = $p_m =~ m/^\[dgit import ([0-9a-z]+) .*\]$/m;
443 my @orig_ps = grep { ($_->{IsDgitImport}//'X') eq 'orig' } @p;
445 if (!(grep { !$_->{IsOrigin} } @p) and
446 (@orig_ps >= @p - 1) and
447 $m2 =~ s{^\[(dgit import unpatched .*)\]$}{[was: $1]}m) {
449 return $classify->(qw(DgitImportUnpatched),
450 OrigParents => \@orig_ps);
453 my ($stype, $series) = git_cat_file "$t:debian/patches/series";
454 my $haspatches = $stype ne 'missing' && $series =~ m/^\s*[^#\n\t ]/m;
456 # How to decide about l/r ordering of breakwater merges ? git
457 # --topo-order prefers to expand 2nd parent first. There's
458 # already an easy rune to look for debian/ history anyway (git log
459 # debian/) so debian breakwater branch should be 1st parent; that
460 # way also there's also an easy rune to look for the upstream
461 # patches (--topo-order).
463 # The above tells us which way *we* will generate them. But we
464 # might encounter ad-hoc breakwater merges generated manually,
465 # which might be the other way around. In principle, in some odd
466 # situations, a breakwater merge might have two identical parents.
467 # In that case we guess which way round it is (ie, which parent
468 # has the upstream history). The order of the 2-iteration loop
469 # controls which guess we make.
471 foreach my $prevbrw (qw(0 1)) {
474 !$p[$prevbrw]{IsOrigin} && # breakwater never starts with an origin
475 !($p[!$prevbrw]{Differs} & ~DS_DEB) && # no non-debian changess
476 !($p[$prevbrw]{Differs} & ~D_UPS)) { # no non-upstream changes
477 return $classify->(qw(BreakwaterUpstreamMerge),
478 OrigParents => [ $p[!$prevbrw] ]);
482 # multi-orig upstreams are represented with a breakwater merge
483 # from a single upstream commit which combines the orig tarballs
485 return $unknown->("complex merge");
491 $nogenerate,$report) = @_;
492 # => ($tip, $breakwater_tip, $last_upstream_merge_in_breakwater)
493 # (or nothing, if $nogenerate)
495 printdebug "*** WALK $input ".($nogenerate//0)." ".($report//'-')."\n";
497 # go through commits backwards
498 # we generate two lists of commits to apply:
499 # breakwater branch and upstream patches
500 my (@brw_cl, @upp_cl, @processed);
507 my ($prose, $info) = @_;
511 $ms .= "\n\n[git-debrebase$info: $prose]\n";
514 my $rewrite_from_here = sub {
515 my $sp_cl = { SpecialMethod => 'StartRewrite' };
516 push @brw_cl, $sp_cl;
517 push @processed, $sp_cl;
522 my $prprdelim = sub { print $report $prdelim if $report; $prdelim=""; };
525 return unless $report;
526 print $report $prdelim, @_;
530 my $bomb = sub { # usage: return $bomb->();
531 print $report " Unprocessable" if $report;
534 return (undef,undef);
536 die "commit $cur: Cannot cope with this commit (d.".
537 (join ' ', map { sprintf "%#x", $_->{Differs} }
538 @{ $cl->{Parents} }). ")";
544 my $build_start = sub {
545 my ($msg, $parent) = @_;
548 no warnings qw(exiting); last;
551 my $last_upstream_update;
555 my $ty = $cl->{Type};
556 my $st = $cl->{SubType};
557 $prline->("$cl->{CommitId} $cl->{Type}");
558 $found{$ty. ( defined($st) ? "-$st" : '' )}++;
559 push @processed, $cl;
560 my $p0 = @{ $cl->{Parents} }==1 ? $cl->{Parents}[0]{CommitId} : undef;
561 if ($ty eq 'AddPatches') {
563 $rewrite_from_here->();
565 } elsif ($ty eq 'Packaging' or $ty eq 'Changelog') {
569 } elsif ($ty eq 'BreakwaterStart') {
570 $last_upstream_update = $cur;
571 $build_start->('FirstPackaging', $cur);
572 } elsif ($ty eq 'Upstream') {
576 } elsif ($ty eq 'Mixed') {
579 my $cls = { %$cl, $xmsg->("split mixed commit: $wh part") };
582 $queue->(\@brw_cl, "debian");
583 $queue->(\@upp_cl, "upstream");
584 $rewrite_from_here->();
587 } elsif ($ty eq 'Pseudomerge') {
588 my $contrib = $cl->{Contributor}{CommitId};
589 print $report " Contributor=$contrib" if $report;
590 push @pseudomerges, $cl;
591 $rewrite_from_here->();
594 } elsif ($ty eq 'BreakwaterUpstreamMerge') {
595 $last_upstream_update = $cur;
596 $build_start->("PreviousBreakwater", $cur);
597 } elsif ($ty eq 'DgitImportUnpatched') {
598 my $pm = $pseudomerges[-1];
600 # To an extent, this is heuristic. Imports don't have
601 # a useful history of the debian/ branch. We assume
602 # that the first pseudomerge after an import has a
603 # useful history of debian/, and ignore the histories
604 # from later pseudomerges. Often the first pseudomerge
605 # will be the dgit import of the upload to the actual
606 # suite intended by the non-dgit NMUer, and later
607 # pseudomerges may represent in-archive copies.
608 my $ovwrs = $pm->{Overwritten};
609 printf $report " PM=%s \@Overwr:%d", $pm, (scalar @$ovwrs)
612 printdebug "*** WALK BOMB DgitImportUnpatched\n";
615 my $ovwr = $ovwrs->[0]{CommitId};
616 printf $report " Overwr=%s", $ovwr if $report;
617 # This import has a tree which is just like a
618 # breakwater tree, but it has the wrong history. It
619 # ought to have the previous breakwater (which the
620 # pseudomerge overwrote) as an ancestor. That will
621 # make the history of the debian/ files correct. As
622 # for the upstream version: either it's the same as
623 # was ovewritten (ie, same as the previous
624 # breakwater), in which case that history is precisely
625 # right; or, otherwise, it was a non-gitish upload of a
626 # new upstream version. We can tell these apart by
627 # looking at the tree of the supposed upstream.
630 SpecialMethod => 'DgitImportDebianUpdate',
631 $xmsg->("convert dgit import: debian changes")
633 my $differs = (get_differs $ovwr, $cl->{Tree});
634 printf $report " Differs=%#x", $differs if $report;
635 if ($differs & D_UPS) {
636 printf $report " D_UPS" if $report;
637 # This will also trigger if a non-dgit git-based NMU
638 # deleted .gitignore (which is a thing that some of
639 # the existing git tools do if the user doesn't
640 # somehow tell them not to). Ah well.
643 SpecialMethod => 'DgitImportUpstreamUpdate',
644 $xmsg->("convert dgit import: upstream changes",
648 $prline->(" Import");
649 $rewrite_from_here->();
650 $upp_limit //= $#upp_cl; # further, deeper, patches discarded
651 die 'BUG $upp_limit is not used anywhere?';
655 # Everything is from this import. This kind of import
656 # is already in valid breakwater format, with the
657 # patches as commits.
658 printf $report " NoPM" if $report;
659 # last thing we processed will have been the first patch,
660 # if there is one; which is fine, so no need to rewrite
661 # on account of this import
662 $build_start->("ImportOrigin", $cur);
666 printdebug "*** WALK BOMB unrecognised\n";
672 printdebug "*** WALK prep done cur=$cur".
673 " brw $#brw_cl upp $#upp_cl proc $#processed pm $#pseudomerges\n";
675 return if $nogenerate;
677 # Now we build it back up again
683 my $read_tree_debian = sub {
685 read_tree_subdir 'debian', "$treeish:debian";
686 rm_subdir_cached 'debian/patches';
688 my $read_tree_upstream = sub {
690 runcmd @git, qw(read-tree), $treeish;
691 $read_tree_debian->($build);
694 my $committer_authline = calculate_committer_authline();
696 printdebug "WALK REBUILD $build ".(scalar @processed)."\n";
698 confess "internal error" unless $build eq (pop @processed)->{CommitId};
701 mkdir $rd or $!==EEXIST or die $!;
703 runcmd @git, qw(read-tree), $build;
704 foreach my $cl (qw(Debian), (reverse @brw_cl),
705 { SpecialMethod => 'RecordBreakwaterTip' },
706 qw(Upstream), (reverse @upp_cl)) {
708 $current_method = $cl;
711 my $method = $cl->{SpecialMethod} // $current_method;
712 my @parents = ($build);
713 my $cltree = $cl->{CommitId};
714 printdebug "WALK BUILD ".($cltree//'undef').
715 " $method (rewriting=$rewriting)\n";
716 if ($method eq 'Debian') {
717 $read_tree_debian->($cltree);
718 } elsif ($method eq 'Upstream') {
719 $read_tree_upstream->($cltree);
720 } elsif ($method eq 'StartRewrite') {
723 } elsif ($method eq 'RecordBreakwaterTip') {
724 $breakwater = $build;
726 } elsif ($method eq 'DgitImportDebianUpdate') {
727 $read_tree_debian->($cltree);
728 rm_subdir_cached qw(debian/patches);
729 } elsif ($method eq 'DgitImportUpstreamUpdate') {
730 $read_tree_upstream->($cltree);
731 push @parents, map { $_->{CommitId} } @{ $cl->{OrigParents} };
736 my $procd = (pop @processed) // 'UNDEF';
739 printdebug "WALK REWRITING NOW cl=$cl procd=$procd\n";
742 my $newtree = cmdoutput @git, qw(write-tree);
744 $ch =~ s{^tree .*}{tree $newtree}m or confess "$ch ?";
745 $ch =~ s{^parent .*\n}{}m;
746 $ch =~ s{(?=^author)}{
747 join '', map { "parent $_\n" } @parents
748 }me or confess "$ch ?";
750 $ch =~ s{^committer .*$}{$committer_authline}m
753 my $cf = "$rd/m$rewriting";
754 open CD, ">", $cf or die $!;
755 print CD $ch, "\n", $cl->{Msg} or die $!;
757 my @cmd = (@git, qw(hash-object));
758 push @cmd, qw(-w) if $rewriting;
759 push @cmd, qw(-t commit), $cf;
760 my $newcommit = cmdoutput @cmd;
761 confess "$ch ?" unless $rewriting or $newcommit eq $cl->{CommitId};
763 if (grep { $method eq $_ } qw(DgitImportUpstreamUpdate)) {
764 $last_upstream_update = $cur;
769 my $final_check = get_differs $build, $input;
770 die sprintf "internal error %#x %s %s", $final_check, $build, $input
771 if $final_check & ~D_PAT_ADD;
773 my @r = ($build, $breakwater, $last_upstream_update);
774 printdebug "*** WALK RETURN @r\n";
778 sub get_head () { return git_rev_parse qw(HEAD); }
780 sub update_head ($$$) {
781 my ($old, $new, $mrest) = @_;
782 runcmd @git, qw(update-ref -m), "debrebase: $mrest", 'HEAD', $new, $old;
785 sub update_head_checkout ($$$) {
786 my ($old, $new, $mrest) = @_;
787 update_head $old, $new, $mrest;
788 runcmd @git, qw(reset --hard);
791 sub update_head_postlaunder ($$$) {
792 my ($old, $tip, $reflogmsg) = @_;
793 return if $tip eq $old;
794 print "git-debrebase: laundered (head was $old)\n";
795 update_head $old, $tip, $reflogmsg;
796 # no tree changes except debian/patches
797 runcmd @git, qw(rm --quiet --ignore-unmatch -rf debian/patches);
801 badusage "no arguments to launder allowed" if @ARGV;
802 my $old = get_head();
803 my ($tip,$breakwater,$last_upstream_merge) = walk $old;
804 update_head_postlaunder $old, $tip, 'launder';
805 printf "# breakwater tip\n%s\n", $breakwater;
806 printf "# working tip\n%s\n", $tip;
807 printf "# last upstream merge\n%s\n", $last_upstream_merge;
810 sub defaultcmd_rebase () {
811 my $old = get_head();
812 my ($tip,$breakwater) = walk $old;
813 update_head_postlaunder $old, $tip, 'launder for rebase';
814 @ARGV = qw(-i) unless @ARGV; # make configurable
815 runcmd @git, qw(rebase), @ARGV, $breakwater;
819 die if ($ARGV[0]//'') =~ m/^-/;
820 badusage "too many arguments to analyse" if @ARGV>1;
823 $old = git_rev_parse $old;
827 my ($dummy,$breakwater) = walk $old, 1,*STDOUT;
828 STDOUT->error and die $!;
831 sub cmd_new_upstream_v0 () {
832 # tree should be clean and this is not checked
833 # automatically and unconditionally launders before rebasing
834 # if rebase --abort is used, laundering has still been done
838 badusage "need NEW-VERSION UPS-COMMITTISH" unless @ARGV >= 2;
840 # parse args - low commitment
841 my $new_version = (new Dpkg::Version scalar(shift @ARGV), check => 1);
842 my $new_upstream_version = $new_version->version();
844 my $new_upstream = git_rev_parse shift @ARGV;
847 my ($n, @x) = @_; # may be ''
848 my $pc = $pieces{$n} //= {
850 Desc => ($n ? "upstream piece \`$n'" : "upstream (main piece"),
852 while (my $k = shift @x) { $pc->{$k} = shift @x; }
858 my ($n, @x) = @_; # may be ''
859 my $pc = $piece->($n, @x, NewIx => (scalar @newpieces));
860 push @newpieces, $pc;
865 New => $new_upstream,
867 while (@ARGV && $ARGV[0] !~ m{^-}) {
870 badusage "for each EXTRA-UPS-NAME need EXTRA-UPS-COMMITISH"
871 unless @ARGV && $ARGV[0] !~ m{^-};
873 my $c = git_rev_parse shift @ARGV;
874 die unless $n =~ m/^$extra_orig_namepart_re$/;
875 $newpiece->($n, New => $c);
878 # now we need to investigate the branch this generates the
879 # laundered version but we don't switch to it yet
880 my $old_head = get_head();
881 my ($old_laundered_tip,$old_bw,$old_upstream_update) = walk $old_head;
883 my $old_bw_cl = classify $old_bw;
884 my $old_upstream_update_cl = classify $old_upstream_update;
885 confess unless $old_upstream_update_cl->{OrigParents};
886 my $old_upstream = parsecommit
887 $old_upstream_update_cl->{OrigParents}[0]{CommitId};
889 $piece->('', Old => $old_upstream->{CommitId});
891 if ($old_upstream->{Msg} =~ m{^\[git-debrebase }m) {
892 if ($old_upstream->{Msg} =~
893 m{^\[git-debrebase upstream-combine \.((?: $extra_orig_namepart_re)+)\:.*\]$}m
895 my @oldpieces = ('', split / /, $1);
896 my $parentix = -1 + scalar @{ $old_upstream->{Parents} };
897 foreach my $i (0..$#oldpieces) {
898 my $n = $oldpieces[$i];
899 $piece->($n, Old => $old_upstream->{CommitId}.'^'.$parentix);
902 fproblem 'upstream-confusing',
903 "previous upstream $old_upstream->{CommitId} is from".
904 " git-debrebase but not an \`upstream-combine' commit";
908 foreach my $pc (values %pieces) {
910 fproblem 'upstream-new-piece',
911 "introducing upstream piece \`$pc->{Name}'";
912 } elsif (!$pc->{New}) {
913 fproblem 'upstream-rm-piece',
914 "dropping upstream piece \`$pc->{Name}'";
915 } elsif (!is_fast_fwd $pc->{Old}, $pc->{New}) {
916 fproblem 'upstream-not-ff',
917 "not fast forward: $pc->{Name} $pc->{Old}..$pc->{New}";
921 printdebug "%pieces = ", (dd \%pieces), "\n";
922 printdebug "\@newpieces = ", (dd \@newpieces), "\n";
924 fproblems_maybe_bail();
930 my @upstream_merge_parents;
932 if (!any_fproblems()) {
933 push @upstream_merge_parents, $old_upstream->{CommitId};
936 foreach my $pc (@newpieces) { # always has '' first
938 read_tree_subdir $pc->{Name}, $pc->{New};
940 runcmd @git, qw(read-tree), $pc->{New};
942 push @upstream_merge_parents, $pc->{New};
945 # index now contains the new upstream
947 if (@newpieces > 1) {
948 # need to make the upstream subtree merge commit
949 $new_upstream = make_commit \@upstream_merge_parents,
950 [ "Combine upstreams for $new_upstream_version",
951 ("[git-debrebase upstream-combine . ".
952 (join " ", map { $_->{Name} } @newpieces[1..$#newpieces]).
957 # $new_upstream is either the single upstream commit, or the
958 # combined commit we just made. Either way it will be the
959 # "upstream" parent of the breakwater special merge.
961 read_tree_subdir 'debian', "$old_bw:debian";
963 # index now contains the breakwater merge contents
964 $new_bw = make_commit [ $old_bw, $new_upstream ],
965 [ "Update to upstream $new_upstream_version",
966 "[git-debrebase breakwater: new upstream $new_upstream_version, merge]",
969 # Now we have to add a changelog stanza so the Debian version
971 die if unlink "debian";
972 die $! unless $!==ENOENT or $!==ENOTEMPTY;
973 unlink "debian/changelog" or $!==ENOENT or die $!;
974 mkdir "debian" or die $!;
975 open CN, ">", "debian/changelog" or die $!;
976 my $oldclog = git_cat_file ":debian/changelog";
977 $oldclog =~ m/^($package_re) \(\S+\) / or
978 fail "cannot parse old changelog to get package name";
980 print CN <<END, $oldclog or die $!;
981 $p ($new_version) UNRELEASED; urgency=medium
983 * Update to new upstream version $new_upstream_version.
989 runcmd @git, qw(update-index --add --replace), 'debian/changelog';
991 # Now we have the final new breakwater branch in the index
992 $new_bw = make_commit [ $new_bw ],
993 [ "Update changelog for new upstream $new_upstream_version",
994 "[git-debrebase: new upstream $new_upstream_version, changelog]",
998 # we have constructed the new breakwater. we now need to commit to
999 # the laundering output, because git-rebase can't easily be made
1000 # to make a replay list which is based on some other branch
1002 update_head_postlaunder $old_head, $old_laundered_tip,
1003 'launder for new upstream';
1005 my @cmd = (@git, qw(rebase --onto), $new_bw, $old_bw, @ARGV);
1007 # now it's for the user to sort out
1010 sub cmd_gbp2debrebase () {
1011 badusage "needs 1 optional argument, the upstream" unless @ARGV<=1;
1012 my ($upstream_spec) = @ARGV;
1013 $upstream_spec //= 'refs/heads/upstream';
1014 my $upstream = git_rev_parse $upstream_spec;
1015 my $old_head = get_head();
1017 my $upsdiff = get_differs $upstream, $old_head;
1018 if ($upsdiff & D_UPS) {
1019 runcmd @git, qw(--no-pager diff),
1020 $upstream, $old_head,
1021 qw( -- :!/debian :/);
1022 fail "upstream ($upstream_spec) and HEAD are not identical in upstream files";
1025 if (!is_fast_fwd $upstream, $old_head) {
1026 fproblem 'upstream-not-ancestor',
1027 "upstream ($upstream) is not an ancestor of HEAD";
1029 my $wrong = cmdoutput
1030 (@git, qw(rev-list --ancestry-path), "$upstream..HEAD",
1031 qw(-- :/ :!/debian));
1032 if (length $wrong) {
1033 fproblem 'unexpected-upstream-changes',
1034 "history between upstream ($upstream) and HEAD contains direct changes to upstream files - are you sure this is a gbp (patches-unapplied) branch?";
1035 print STDERR "list expected changes with: git log --stat --ancestry-path $upstream_spec..HEAD -- :/ ':!/debian'\n";
1039 if ((git_cat_file "$upstream:debian")[0] ne 'missing') {
1040 fproblem 'upstream-has-debian',
1041 "upstream ($upstream) contains debian/ directory";
1044 fproblems_maybe_bail();
1050 runcmd @git, qw(checkout -q -b gdr-internal), $old_head;
1051 # make a branch out of the patch queue - we'll want this in a mo
1052 runcmd qw(gbp pq import);
1053 # strip the patches out
1054 runcmd @git, qw(checkout -q gdr-internal~0);
1055 rm_subdir_cached 'debian/patches';
1056 $work = make_commit ['HEAD'], [
1057 'git-debrebase import: drop patch queue',
1058 'Delete debian/patches, as part of converting to git-debrebase format.',
1059 '[git-debrebase: gbp2debrebase, drop patches]'
1061 # make the breakwater pseudomerge
1062 # the tree is already exactly right
1063 $work = make_commit [$work, $upstream], [
1064 'git-debrebase import: declare upstream',
1065 'First breakwater merge.',
1066 '[git-debrebase breakwater: declare upstream]'
1069 # rebase the patch queue onto the new breakwater
1070 runcmd @git, qw(reset --quiet --hard patch-queue/gdr-internal);
1071 runcmd @git, qw(rebase --quiet --onto), $work, qw(gdr-internal);
1075 update_head_checkout $old_head, $work, 'gbp2debrebase';
1078 sub cmd_downstream_rebase_launder_v0 () {
1079 badusage "needs 1 argument, the baseline" unless @ARGV==1;
1081 $base = git_rev_parse $base;
1082 my $old_head = get_head();
1083 my $current = $old_head;
1086 if ($current eq $base) {
1087 $topmost_keep //= $current;
1088 print " $current BASE stop\n";
1091 my $cl = classify $current;
1092 print " $current $cl->{Type}";
1094 my $p0 = $cl->{Parents}[0]{CommitId};
1096 if ($cl->{Type} eq 'Pseudomerge') {
1097 print " ^".($cl->{Contributor}{Ix}+1);
1098 $next = $cl->{Contributor}{CommitId};
1099 } elsif ($cl->{Type} eq 'AddPatches' or
1100 $cl->{Type} eq 'Changelog') {
1110 $topmost_keep //= $current;
1112 die "to-be stripped changes not on top of the branch\n"
1117 if ($topmost_keep eq $old_head) {
1118 print "unchanged\n";
1120 print "updating to $topmost_keep\n";
1121 update_head_checkout
1122 $old_head, $topmost_keep,
1123 'downstream-rebase-launder-v0';
1127 GetOptions("D+" => \$debuglevel,
1128 'force!') or die badusage "bad options\n";
1129 initdebug('git-debrebase ');
1130 enabledebug if $debuglevel;
1132 my $toplevel = cmdoutput @git, qw(rev-parse --show-toplevel);
1133 chdir $toplevel or die "chdir $toplevel: $!";
1135 $rd = fresh_playground "$playprefix/misc";
1137 if (!@ARGV || $ARGV[0] =~ m{^-}) {
1138 defaultcmd_rebase();
1140 my $cmd = shift @ARGV;
1143 $cmdfn = ${*::}{"cmd_$cmdfn"};
1145 $cmdfn or badusage "unknown git-debrebase sub-operation $cmd";