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);
93 our $us = qw(git-debrebase);
97 die "bad usage: $m\n";
103 my @cmd = qw(git config -z);
104 push @cmd, qw(--get-all) if wantarray;
106 my $out = cmdoutput @cmd;
107 return split /\0/, $out;
114 my $dd = new Data::Dumper [ $v ];
115 Terse $dd 1; Indent $dd 0; Useqq $dd 1;
121 my $data = (git_cat_file $objid, 'commit');
122 $data =~ m/(?<=\n)\n/ or die "$objid ($data) ?";
126 sub D_UPS () { 0x02; } # upstream files
127 sub D_PAT_ADD () { 0x04; } # debian/patches/ extra patches at end
128 sub D_PAT_OTH () { 0x08; } # debian/patches other changes
129 sub D_DEB_CLOG () { 0x10; } # debian/ (not patches/ or changelog)
130 sub D_DEB_OTH () { 0x20; } # debian/changelog
131 sub DS_DEB () { D_DEB_CLOG | D_DEB_OTH; } # debian/ (not patches/)
133 our $playprefix = 'debrebase';
139 sub in_workarea ($) {
142 my $r = eval { $sub->(); };
143 { local $@; changedir $maindir; }
147 sub fresh_workarea () {
148 $workarea = fresh_playground "$playprefix/work";
149 in_workarea sub { playtree_setup };
152 sub get_differs ($$) {
154 # This resembles quiltify_trees_differ, in dgit, a bit.
155 # But we don't care about modes, or dpkg-source-unrepresentable
156 # changes, and we don't need the plethora of different modes.
157 # Conversely we need to distinguish different kinds of changes to
158 # debian/ and debian/patches/.
163 my ($opts, $limits, $fn) = @_;
164 my @cmd = (@git, qw(diff-tree -z --no-renames));
166 push @cmd, "$_:" foreach $x, $y;
167 push @cmd, '--', @$limits;
168 my $diffs = cmdoutput @cmd;
169 foreach (split /\0/, $diffs) { $fn->(); }
172 $rundiff->([qw(--name-only)], [], sub {
173 $differs |= $_ eq 'debian' ? DS_DEB : D_UPS;
176 if ($differs & DS_DEB) {
178 $rundiff->([qw(--name-only -r)], [qw(debian)], sub {
180 m{^debian/patches/} ? D_PAT_OTH :
181 $_ eq 'debian/changelog' ? D_DEB_CLOG :
184 die "mysterious debian changes $x..$y"
185 unless $differs & (D_PAT_OTH|DS_DEB);
188 if ($differs & D_PAT_OTH) {
190 $differs &= ~D_PAT_OTH;
192 $differs |= D_PAT_OTH;
193 no warnings qw(exiting); last;
195 $rundiff->([qw(--name-status -r)], [qw(debian/patches/)], sub {
196 no warnings qw(exiting);
197 if (!defined $mode) {
200 die unless s{^debian/patches/}{};
202 if ($mode eq 'A' && !m/\.series$/s) {
204 } elsif ($mode eq 'M' && $_ eq 'series') {
205 my $x_s = (git_cat_file "$x:debian/patches/series", 'blob');
206 my $y_s = (git_cat_file "$y:debian/patches/series", 'blob');
207 chomp $x_s; $x_s .= "\n";
208 $ok = $x_s eq substr($y_s, 0, length $x_s);
213 $differs |= $ok ? D_PAT_ADD : D_PAT_OTH;
215 die "mysterious debian/patches changes $x..$y"
216 unless $differs & (D_PAT_ADD|D_PAT_OTH);
219 printdebug sprintf "get_differs %s, %s = %#x\n", $x, $y, $differs;
224 sub commit_pr_info ($) {
226 return Data::Dumper->dump([$r], [qw(commit)]);
229 sub calculate_committer_authline () {
230 my $c = cmdoutput @git, qw(commit-tree --no-gpg-sign -m),
231 'DUMMY COMMIT (git-debrebase)', "HEAD:";
232 my ($h,$m) = get_commit $c;
233 $h =~ m/^committer .*$/m or confess "($h) ?";
237 sub rm_subdir_cached ($) {
239 runcmd @git, qw(rm --quiet -rf --cached --ignore-unmatch), $subdir;
242 sub read_tree_subdir ($$) {
243 my ($subdir, $new_tree_object) = @_;
244 rm_subdir_cached $subdir;
245 runcmd @git, qw(read-tree), "--prefix=$subdir/", $new_tree_object;
248 sub make_commit ($$) {
249 my ($parents, $message_paras) = @_;
250 my $tree = cmdoutput @git, qw(write-tree);
251 my @cmd = (@git, qw(commit-tree), $tree);
252 push @cmd, qw(-p), $_ foreach @$parents;
253 push @cmd, qw(-m), $_ foreach @$message_paras;
254 return cmdoutput @cmd;
257 our @fproblem_force_opts;
258 our $fproblems_forced;
259 our $fproblems_tripped;
262 if (grep { $_ eq $tag } @fproblem_force_opts) {
264 print STDERR "git-debrebase: safety catch overridden (-f$tag): $msg\n";
266 $fproblems_tripped++;
267 print STDERR "git-debrebase: safety catch tripped (-f$tag): $msg\n";
271 sub fproblems_maybe_bail () {
272 if ($fproblems_forced) {
274 "%s: safety catch trips: %d overriden by individual -f options\n",
275 $us, $fproblems_forced;
277 if ($fproblems_tripped) {
280 "%s: safety catch trips: %d overriden by global --force\n",
281 $us, $fproblems_tripped;
284 "%s: safety catch trips: %d blockers (you could -f<tag>, or --force)",
285 $us, $fproblems_tripped;
289 sub any_fproblems () {
290 return $fproblems_forced || $fproblems_tripped;
293 # classify returns an info hash like this
295 # Hdr => # commit headers, including 1 final newline
296 # Msg => # commit message (so one newline is dropped)
298 # Type => (see below)
300 # Ix => $index # ie 0, 1, 2, ...
302 # Differs => return value from get_differs
304 # IsDggitImport => 'orig' 'tarball' 'unpatched' 'package' (as from dgit)
306 # NewMsg => # commit message, but with any [dgit import ...] edited
307 # # to say "[was: ...]"
318 # has additional entres in classification result
319 # Overwritten = [ subset of Parents ]
320 # Contributor = $the_remaining_Parent
322 # DgitImportUnpatched
323 # has additional entry in classification result
324 # OrigParents = [ subset of Parents ]
326 # BreakwaterUpstreamMerge
327 # has additional entry in classification result
328 # OrigParents = [ subset of Parents ] # singleton list
330 sub parsecommit ($;$) {
331 my ($objid, $p_ref) = @_;
332 # => hash with CommitId Hdr Msg Tree Parents
333 # Parents entries have only Ix CommitId
334 # $p_ref, if provided, must be [] and is used as a base for Parents
339 my ($h,$m) = get_commit $objid;
341 my ($t) = $h =~ m/^tree (\w+)$/m or die $objid;
342 my (@ph) = $h =~ m/^parent (\w+)$/mg;
352 foreach my $ph (@ph) {
354 Ix => scalar @$p_ref,
366 my $r = parsecommit($objid, \@p);
370 $p->{Differs} = (get_differs $p->{CommitId}, $t),
373 printdebug "classify $objid \$t=$t \@p",
374 (map { sprintf " %s/%#x", $_->{CommitId}, $_->{Differs} } @p),
378 my ($type, @rest) = @_;
379 $r = { %$r, Type => $type, @rest };
381 printdebug " = $type ".(dd $r)."\n";
387 $r = { %$r, Type => qw(Unknown) };
388 printdebug " ** Unknown\n";
392 my $claims_to_be_breakwater =
393 $r->{Msg} =~ m{^\[git-debrebase breakwater.*\]$}m;
396 if ($claims_to_be_breakwater) {
397 return $unknown->("single-parent git-debrebase breakwater \`merge'");
399 my $d = $r->{Parents}[0]{Differs};
400 if ($d == D_PAT_ADD) {
401 return $classify->(qw(AddPatches));
402 } elsif ($d & (D_PAT_ADD|D_PAT_OTH)) {
403 return $unknown->("edits debian/patches");
404 } elsif ($d & DS_DEB and !($d & ~DS_DEB)) {
405 my ($ty,$dummy) = git_cat_file "$p[0]{CommitId}:debian";
407 if ($d == D_DEB_CLOG) {
408 return $classify->(qw(Changelog));
410 return $classify->(qw(Packaging));
412 } elsif ($ty eq 'missing') {
413 return $classify->(qw(BreakwaterStart));
415 return $unknown->("parent's debian is not a directory");
417 } elsif ($d == D_UPS) {
418 return $classify->(qw(Upstream));
419 } elsif ($d & DS_DEB and $d & D_UPS and !($d & ~(DS_DEB|D_UPS))) {
420 return $classify->(qw(Mixed));
422 return $unknown->("no changes");
424 confess "internal error $objid ?";
428 return $unknown->("origin commit");
431 my @identical = grep { !$_->{Differs} } @p;
432 if (@p == 2 && @identical == 1 && !$claims_to_be_breakwater
433 # breakwater merges can look like pseudomerges, if they are
434 # "declare" commits (ie, there are no upstream changes)
436 my @overwritten = grep { $_->{Differs} } @p;
437 confess "internal error $objid ?" unless @overwritten==1;
438 return $classify->(qw(Pseudomerge),
439 Overwritten => $overwritten[0],
440 Contributor => $identical[0]);
442 if (@p == 2 && @identical == 2) {
443 my @bytime = nsort_by {
444 my ($ph,$pm) = get_commit $_->{CommitId};
445 $ph =~ m/^committer .* (\d+) [-+]\d+$/m or die "$_->{CommitId} ?";
448 return $classify->(qw(Pseudomerge),
449 SubType => qw(Ambiguous),
450 Overwritten => $bytime[0],
451 Contributor => $bytime[1]);
454 my ($p_h, $p_m) = get_commit $p->{CommitId};
455 $p->{IsOrigin} = $p_h !~ m/^parent \w+$/m;
456 ($p->{IsDgitImport},) = $p_m =~ m/^\[dgit import ([0-9a-z]+) .*\]$/m;
458 my @orig_ps = grep { ($_->{IsDgitImport}//'X') eq 'orig' } @p;
460 if (!(grep { !$_->{IsOrigin} } @p) and
461 (@orig_ps >= @p - 1) and
462 $m2 =~ s{^\[(dgit import unpatched .*)\]$}{[was: $1]}m) {
464 return $classify->(qw(DgitImportUnpatched),
465 OrigParents => \@orig_ps);
468 my ($stype, $series) = git_cat_file "$t:debian/patches/series";
469 my $haspatches = $stype ne 'missing' && $series =~ m/^\s*[^#\n\t ]/m;
471 # How to decide about l/r ordering of breakwater merges ? git
472 # --topo-order prefers to expand 2nd parent first. There's
473 # already an easy rune to look for debian/ history anyway (git log
474 # debian/) so debian breakwater branch should be 1st parent; that
475 # way also there's also an easy rune to look for the upstream
476 # patches (--topo-order).
478 # The above tells us which way *we* will generate them. But we
479 # might encounter ad-hoc breakwater merges generated manually,
480 # which might be the other way around. In principle, in some odd
481 # situations, a breakwater merge might have two identical parents.
482 # In that case we guess which way round it is (ie, which parent
483 # has the upstream history). The order of the 2-iteration loop
484 # controls which guess we make.
486 foreach my $prevbrw (qw(0 1)) {
489 !$p[$prevbrw]{IsOrigin} && # breakwater never starts with an origin
490 !($p[!$prevbrw]{Differs} & ~DS_DEB) && # no non-debian changess
491 !($p[$prevbrw]{Differs} & ~D_UPS)) { # no non-upstream changes
492 return $classify->(qw(BreakwaterUpstreamMerge),
493 OrigParents => [ $p[!$prevbrw] ]);
497 # multi-orig upstreams are represented with a breakwater merge
498 # from a single upstream commit which combines the orig tarballs
500 return $unknown->("complex merge");
506 $nogenerate,$report) = @_;
507 # => ($tip, $breakwater_tip, $last_upstream_merge_in_breakwater)
508 # (or nothing, if $nogenerate)
510 printdebug "*** WALK $input ".($nogenerate//0)." ".($report//'-')."\n";
512 # go through commits backwards
513 # we generate two lists of commits to apply:
514 # breakwater branch and upstream patches
515 my (@brw_cl, @upp_cl, @processed);
522 my ($prose, $info) = @_;
526 $ms .= "\n\n[git-debrebase$info: $prose]\n";
529 my $rewrite_from_here = sub {
530 my $sp_cl = { SpecialMethod => 'StartRewrite' };
531 push @brw_cl, $sp_cl;
532 push @processed, $sp_cl;
537 my $prprdelim = sub { print $report $prdelim if $report; $prdelim=""; };
540 return unless $report;
541 print $report $prdelim, @_;
545 my $bomb = sub { # usage: return $bomb->();
546 print $report " Unprocessable" if $report;
549 return (undef,undef);
551 die "commit $cur: Cannot cope with this commit (d.".
552 (join ' ', map { sprintf "%#x", $_->{Differs} }
553 @{ $cl->{Parents} }). ")";
559 my $build_start = sub {
560 my ($msg, $parent) = @_;
563 no warnings qw(exiting); last;
566 my $last_upstream_update;
570 my $ty = $cl->{Type};
571 my $st = $cl->{SubType};
572 $prline->("$cl->{CommitId} $cl->{Type}");
573 $found{$ty. ( defined($st) ? "-$st" : '' )}++;
574 push @processed, $cl;
575 my $p0 = @{ $cl->{Parents} }==1 ? $cl->{Parents}[0]{CommitId} : undef;
576 if ($ty eq 'AddPatches') {
578 $rewrite_from_here->();
580 } elsif ($ty eq 'Packaging' or $ty eq 'Changelog') {
584 } elsif ($ty eq 'BreakwaterStart') {
585 $last_upstream_update = $cur;
586 $build_start->('FirstPackaging', $cur);
587 } elsif ($ty eq 'Upstream') {
591 } elsif ($ty eq 'Mixed') {
594 my $cls = { %$cl, $xmsg->("split mixed commit: $wh part") };
597 $queue->(\@brw_cl, "debian");
598 $queue->(\@upp_cl, "upstream");
599 $rewrite_from_here->();
602 } elsif ($ty eq 'Pseudomerge') {
603 my $contrib = $cl->{Contributor}{CommitId};
604 print $report " Contributor=$contrib" if $report;
605 push @pseudomerges, $cl;
606 $rewrite_from_here->();
609 } elsif ($ty eq 'BreakwaterUpstreamMerge') {
610 $last_upstream_update = $cur;
611 $build_start->("PreviousBreakwater", $cur);
612 } elsif ($ty eq 'DgitImportUnpatched') {
613 my $pm = $pseudomerges[-1];
615 # To an extent, this is heuristic. Imports don't have
616 # a useful history of the debian/ branch. We assume
617 # that the first pseudomerge after an import has a
618 # useful history of debian/, and ignore the histories
619 # from later pseudomerges. Often the first pseudomerge
620 # will be the dgit import of the upload to the actual
621 # suite intended by the non-dgit NMUer, and later
622 # pseudomerges may represent in-archive copies.
623 my $ovwrs = $pm->{Overwritten};
624 printf $report " PM=%s \@Overwr:%d", $pm, (scalar @$ovwrs)
627 printdebug "*** WALK BOMB DgitImportUnpatched\n";
630 my $ovwr = $ovwrs->[0]{CommitId};
631 printf $report " Overwr=%s", $ovwr if $report;
632 # This import has a tree which is just like a
633 # breakwater tree, but it has the wrong history. It
634 # ought to have the previous breakwater (which the
635 # pseudomerge overwrote) as an ancestor. That will
636 # make the history of the debian/ files correct. As
637 # for the upstream version: either it's the same as
638 # was ovewritten (ie, same as the previous
639 # breakwater), in which case that history is precisely
640 # right; or, otherwise, it was a non-gitish upload of a
641 # new upstream version. We can tell these apart by
642 # looking at the tree of the supposed upstream.
645 SpecialMethod => 'DgitImportDebianUpdate',
646 $xmsg->("convert dgit import: debian changes")
648 my $differs = (get_differs $ovwr, $cl->{Tree});
649 printf $report " Differs=%#x", $differs if $report;
650 if ($differs & D_UPS) {
651 printf $report " D_UPS" if $report;
652 # This will also trigger if a non-dgit git-based NMU
653 # deleted .gitignore (which is a thing that some of
654 # the existing git tools do if the user doesn't
655 # somehow tell them not to). Ah well.
658 SpecialMethod => 'DgitImportUpstreamUpdate',
659 $xmsg->("convert dgit import: upstream changes",
663 $prline->(" Import");
664 $rewrite_from_here->();
665 $upp_limit //= $#upp_cl; # further, deeper, patches discarded
666 die 'BUG $upp_limit is not used anywhere?';
670 # Everything is from this import. This kind of import
671 # is already in valid breakwater format, with the
672 # patches as commits.
673 printf $report " NoPM" if $report;
674 # last thing we processed will have been the first patch,
675 # if there is one; which is fine, so no need to rewrite
676 # on account of this import
677 $build_start->("ImportOrigin", $cur);
681 printdebug "*** WALK BOMB unrecognised\n";
687 printdebug "*** WALK prep done cur=$cur".
688 " brw $#brw_cl upp $#upp_cl proc $#processed pm $#pseudomerges\n";
690 return if $nogenerate;
692 # Now we build it back up again
698 my $read_tree_debian = sub {
700 read_tree_subdir 'debian', "$treeish:debian";
701 rm_subdir_cached 'debian/patches';
703 my $read_tree_upstream = sub {
705 runcmd @git, qw(read-tree), $treeish;
706 $read_tree_debian->($build);
709 my $committer_authline = calculate_committer_authline();
711 printdebug "WALK REBUILD $build ".(scalar @processed)."\n";
713 confess "internal error" unless $build eq (pop @processed)->{CommitId};
716 mkdir $rd or $!==EEXIST or die $!;
718 runcmd @git, qw(read-tree), $build;
719 foreach my $cl (qw(Debian), (reverse @brw_cl),
720 { SpecialMethod => 'RecordBreakwaterTip' },
721 qw(Upstream), (reverse @upp_cl)) {
723 $current_method = $cl;
726 my $method = $cl->{SpecialMethod} // $current_method;
727 my @parents = ($build);
728 my $cltree = $cl->{CommitId};
729 printdebug "WALK BUILD ".($cltree//'undef').
730 " $method (rewriting=$rewriting)\n";
731 if ($method eq 'Debian') {
732 $read_tree_debian->($cltree);
733 } elsif ($method eq 'Upstream') {
734 $read_tree_upstream->($cltree);
735 } elsif ($method eq 'StartRewrite') {
738 } elsif ($method eq 'RecordBreakwaterTip') {
739 $breakwater = $build;
741 } elsif ($method eq 'DgitImportDebianUpdate') {
742 $read_tree_debian->($cltree);
743 rm_subdir_cached qw(debian/patches);
744 } elsif ($method eq 'DgitImportUpstreamUpdate') {
745 $read_tree_upstream->($cltree);
746 push @parents, map { $_->{CommitId} } @{ $cl->{OrigParents} };
751 my $procd = (pop @processed) // 'UNDEF';
754 printdebug "WALK REWRITING NOW cl=$cl procd=$procd\n";
757 my $newtree = cmdoutput @git, qw(write-tree);
759 $ch =~ s{^tree .*}{tree $newtree}m or confess "$ch ?";
760 $ch =~ s{^parent .*\n}{}m;
761 $ch =~ s{(?=^author)}{
762 join '', map { "parent $_\n" } @parents
763 }me or confess "$ch ?";
765 $ch =~ s{^committer .*$}{$committer_authline}m
768 my $cf = "$rd/m$rewriting";
769 open CD, ">", $cf or die $!;
770 print CD $ch, "\n", $cl->{Msg} or die $!;
772 my @cmd = (@git, qw(hash-object));
773 push @cmd, qw(-w) if $rewriting;
774 push @cmd, qw(-t commit), $cf;
775 my $newcommit = cmdoutput @cmd;
776 confess "$ch ?" unless $rewriting or $newcommit eq $cl->{CommitId};
778 if (grep { $method eq $_ } qw(DgitImportUpstreamUpdate)) {
779 $last_upstream_update = $cur;
784 my $final_check = get_differs $build, $input;
785 die sprintf "internal error %#x %s %s", $final_check, $build, $input
786 if $final_check & ~D_PAT_ADD;
788 my @r = ($build, $breakwater, $last_upstream_update);
789 printdebug "*** WALK RETURN @r\n";
793 sub get_head () { return git_rev_parse qw(HEAD); }
795 sub update_head ($$$) {
796 my ($old, $new, $mrest) = @_;
797 runcmd @git, qw(update-ref -m), "debrebase: $mrest", 'HEAD', $new, $old;
800 sub update_head_checkout ($$$) {
801 my ($old, $new, $mrest) = @_;
802 update_head $old, $new, $mrest;
803 runcmd @git, qw(reset --hard);
806 sub update_head_postlaunder ($$$) {
807 my ($old, $tip, $reflogmsg) = @_;
808 return if $tip eq $old;
809 print "git-debrebase: laundered (head was $old)\n";
810 update_head $old, $tip, $reflogmsg;
811 # no tree changes except debian/patches
812 runcmd @git, qw(rm --quiet --ignore-unmatch -rf debian/patches);
816 badusage "no arguments to launder allowed" if @ARGV;
817 my $old = get_head();
818 my ($tip,$breakwater,$last_upstream_merge) = walk $old;
819 update_head_postlaunder $old, $tip, 'launder';
820 printf "# breakwater tip\n%s\n", $breakwater;
821 printf "# working tip\n%s\n", $tip;
822 printf "# last upstream merge\n%s\n", $last_upstream_merge;
825 sub defaultcmd_rebase () {
826 my $old = get_head();
827 my ($tip,$breakwater) = walk $old;
828 update_head_postlaunder $old, $tip, 'launder for rebase';
829 @ARGV = qw(-i) unless @ARGV; # make configurable
830 runcmd @git, qw(rebase), @ARGV, $breakwater;
834 die if ($ARGV[0]//'') =~ m/^-/;
835 badusage "too many arguments to analyse" if @ARGV>1;
838 $old = git_rev_parse $old;
842 my ($dummy,$breakwater) = walk $old, 1,*STDOUT;
843 STDOUT->error and die $!;
846 sub cmd_new_upstream_v0 () {
847 # tree should be clean and this is not checked
848 # automatically and unconditionally launders before rebasing
849 # if rebase --abort is used, laundering has still been done
853 badusage "need NEW-VERSION UPS-COMMITTISH" unless @ARGV >= 2;
855 # parse args - low commitment
856 my $new_version = (new Dpkg::Version scalar(shift @ARGV), check => 1);
857 my $new_upstream_version = $new_version->version();
859 my $new_upstream = git_rev_parse shift @ARGV;
862 my ($n, @x) = @_; # may be ''
863 my $pc = $pieces{$n} //= {
865 Desc => ($n ? "upstream piece \`$n'" : "upstream (main piece"),
867 while (my $k = shift @x) { $pc->{$k} = shift @x; }
873 my ($n, @x) = @_; # may be ''
874 my $pc = $piece->($n, @x, NewIx => (scalar @newpieces));
875 push @newpieces, $pc;
880 New => $new_upstream,
882 while (@ARGV && $ARGV[0] !~ m{^-}) {
885 badusage "for each EXTRA-UPS-NAME need EXTRA-UPS-COMMITISH"
886 unless @ARGV && $ARGV[0] !~ m{^-};
888 my $c = git_rev_parse shift @ARGV;
889 die unless $n =~ m/^$extra_orig_namepart_re$/;
890 $newpiece->($n, New => $c);
893 # now we need to investigate the branch this generates the
894 # laundered version but we don't switch to it yet
895 my $old_head = get_head();
896 my ($old_laundered_tip,$old_bw,$old_upstream_update) = walk $old_head;
898 my $old_bw_cl = classify $old_bw;
899 my $old_upstream_update_cl = classify $old_upstream_update;
900 confess unless $old_upstream_update_cl->{OrigParents};
901 my $old_upstream = parsecommit
902 $old_upstream_update_cl->{OrigParents}[0]{CommitId};
904 $piece->('', Old => $old_upstream->{CommitId});
906 if ($old_upstream->{Msg} =~ m{^\[git-debrebase }m) {
907 if ($old_upstream->{Msg} =~
908 m{^\[git-debrebase upstream-combine \.((?: $extra_orig_namepart_re)+)\:.*\]$}m
910 my @oldpieces = ('', split / /, $1);
911 my $parentix = -1 + scalar @{ $old_upstream->{Parents} };
912 foreach my $i (0..$#oldpieces) {
913 my $n = $oldpieces[$i];
914 $piece->($n, Old => $old_upstream->{CommitId}.'^'.$parentix);
917 fproblem 'upstream-confusing',
918 "previous upstream $old_upstream->{CommitId} is from".
919 " git-debrebase but not an \`upstream-combine' commit";
923 foreach my $pc (values %pieces) {
925 fproblem 'upstream-new-piece',
926 "introducing upstream piece \`$pc->{Name}'";
927 } elsif (!$pc->{New}) {
928 fproblem 'upstream-rm-piece',
929 "dropping upstream piece \`$pc->{Name}'";
930 } elsif (!is_fast_fwd $pc->{Old}, $pc->{New}) {
931 fproblem 'upstream-not-ff',
932 "not fast forward: $pc->{Name} $pc->{Old}..$pc->{New}";
936 printdebug "%pieces = ", (dd \%pieces), "\n";
937 printdebug "\@newpieces = ", (dd \@newpieces), "\n";
939 fproblems_maybe_bail();
945 my @upstream_merge_parents;
947 if (!any_fproblems()) {
948 push @upstream_merge_parents, $old_upstream->{CommitId};
951 foreach my $pc (@newpieces) { # always has '' first
953 read_tree_subdir $pc->{Name}, $pc->{New};
955 runcmd @git, qw(read-tree), $pc->{New};
957 push @upstream_merge_parents, $pc->{New};
960 # index now contains the new upstream
962 if (@newpieces > 1) {
963 # need to make the upstream subtree merge commit
964 $new_upstream = make_commit \@upstream_merge_parents,
965 [ "Combine upstreams for $new_upstream_version",
966 ("[git-debrebase upstream-combine . ".
967 (join " ", map { $_->{Name} } @newpieces[1..$#newpieces]).
972 # $new_upstream is either the single upstream commit, or the
973 # combined commit we just made. Either way it will be the
974 # "upstream" parent of the breakwater special merge.
976 read_tree_subdir 'debian', "$old_bw:debian";
978 # index now contains the breakwater merge contents
979 $new_bw = make_commit [ $old_bw, $new_upstream ],
980 [ "Update to upstream $new_upstream_version",
981 "[git-debrebase breakwater: new upstream $new_upstream_version, merge]",
984 # Now we have to add a changelog stanza so the Debian version
986 die if unlink "debian";
987 die $! unless $!==ENOENT or $!==ENOTEMPTY;
988 unlink "debian/changelog" or $!==ENOENT or die $!;
989 mkdir "debian" or die $!;
990 open CN, ">", "debian/changelog" or die $!;
991 my $oldclog = git_cat_file ":debian/changelog";
992 $oldclog =~ m/^($package_re) \(\S+\) / or
993 fail "cannot parse old changelog to get package name";
995 print CN <<END, $oldclog or die $!;
996 $p ($new_version) UNRELEASED; urgency=medium
998 * Update to new upstream version $new_upstream_version.
1004 runcmd @git, qw(update-index --add --replace), 'debian/changelog';
1006 # Now we have the final new breakwater branch in the index
1007 $new_bw = make_commit [ $new_bw ],
1008 [ "Update changelog for new upstream $new_upstream_version",
1009 "[git-debrebase: new upstream $new_upstream_version, changelog]",
1013 # we have constructed the new breakwater. we now need to commit to
1014 # the laundering output, because git-rebase can't easily be made
1015 # to make a replay list which is based on some other branch
1017 update_head_postlaunder $old_head, $old_laundered_tip,
1018 'launder for new upstream';
1020 my @cmd = (@git, qw(rebase --onto), $new_bw, $old_bw, @ARGV);
1022 # now it's for the user to sort out
1025 sub cmd_gbp2debrebase () {
1026 badusage "needs 1 optional argument, the upstream" unless @ARGV<=1;
1027 my ($upstream_spec) = @ARGV;
1028 $upstream_spec //= 'refs/heads/upstream';
1029 my $upstream = git_rev_parse $upstream_spec;
1030 my $old_head = get_head();
1032 my $upsdiff = get_differs $upstream, $old_head;
1033 if ($upsdiff & D_UPS) {
1034 runcmd @git, qw(--no-pager diff),
1035 $upstream, $old_head,
1036 qw( -- :!/debian :/);
1037 fail "upstream ($upstream_spec) and HEAD are not identical in upstream files";
1040 if (!is_fast_fwd $upstream, $old_head) {
1041 fproblem 'upstream-not-ancestor',
1042 "upstream ($upstream) is not an ancestor of HEAD";
1044 my $wrong = cmdoutput
1045 (@git, qw(rev-list --ancestry-path), "$upstream..HEAD",
1046 qw(-- :/ :!/debian));
1047 if (length $wrong) {
1048 fproblem 'unexpected-upstream-changes',
1049 "history between upstream ($upstream) and HEAD contains direct changes to upstream files - are you sure this is a gbp (patches-unapplied) branch?";
1050 print STDERR "list expected changes with: git log --stat --ancestry-path $upstream_spec..HEAD -- :/ ':!/debian'\n";
1054 if ((git_cat_file "$upstream:debian")[0] ne 'missing') {
1055 fproblem 'upstream-has-debian',
1056 "upstream ($upstream) contains debian/ directory";
1059 fproblems_maybe_bail();
1065 runcmd @git, qw(checkout -q -b gdr-internal), $old_head;
1066 # make a branch out of the patch queue - we'll want this in a mo
1067 runcmd qw(gbp pq import);
1068 # strip the patches out
1069 runcmd @git, qw(checkout -q gdr-internal~0);
1070 rm_subdir_cached 'debian/patches';
1071 $work = make_commit ['HEAD'], [
1072 'git-debrebase import: drop patch queue',
1073 'Delete debian/patches, as part of converting to git-debrebase format.',
1074 '[git-debrebase: gbp2debrebase, drop patches]'
1076 # make the breakwater pseudomerge
1077 # the tree is already exactly right
1078 $work = make_commit [$work, $upstream], [
1079 'git-debrebase import: declare upstream',
1080 'First breakwater merge.',
1081 '[git-debrebase breakwater: declare upstream]'
1084 # rebase the patch queue onto the new breakwater
1085 runcmd @git, qw(reset --quiet --hard patch-queue/gdr-internal);
1086 runcmd @git, qw(rebase --quiet --onto), $work, qw(gdr-internal);
1090 update_head_checkout $old_head, $work, 'gbp2debrebase';
1093 sub cmd_downstream_rebase_launder_v0 () {
1094 badusage "needs 1 argument, the baseline" unless @ARGV==1;
1096 $base = git_rev_parse $base;
1097 my $old_head = get_head();
1098 my $current = $old_head;
1101 if ($current eq $base) {
1102 $topmost_keep //= $current;
1103 print " $current BASE stop\n";
1106 my $cl = classify $current;
1107 print " $current $cl->{Type}";
1109 my $p0 = $cl->{Parents}[0]{CommitId};
1111 if ($cl->{Type} eq 'Pseudomerge') {
1112 print " ^".($cl->{Contributor}{Ix}+1);
1113 $next = $cl->{Contributor}{CommitId};
1114 } elsif ($cl->{Type} eq 'AddPatches' or
1115 $cl->{Type} eq 'Changelog') {
1125 $topmost_keep //= $current;
1127 die "to-be stripped changes not on top of the branch\n"
1132 if ($topmost_keep eq $old_head) {
1133 print "unchanged\n";
1135 print "updating to $topmost_keep\n";
1136 update_head_checkout
1137 $old_head, $topmost_keep,
1138 'downstream-rebase-launder-v0';
1142 GetOptions("D+" => \$debuglevel,
1143 'f=s' => \@fproblem_force_opts,
1144 'force!') or die badusage "bad options\n";
1145 initdebug('git-debrebase ');
1146 enabledebug if $debuglevel;
1148 my $toplevel = cmdoutput @git, qw(rev-parse --show-toplevel);
1149 chdir $toplevel or die "chdir $toplevel: $!";
1151 $rd = fresh_playground "$playprefix/misc";
1153 if (!@ARGV || $ARGV[0] =~ m{^-}) {
1154 defaultcmd_rebase();
1156 my $cmd = shift @ARGV;
1159 $cmdfn = ${*::}{"cmd_$cmdfn"};
1161 $cmdfn or badusage "unknown git-debrebase sub-operation $cmd";