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/>.
22 # undocumented usages:
24 # git-debrebase [<options>] downstream-rebase-launder-v0 # experimental
26 # problems / outstanding questions:
28 # * dgit push with a `3.0 (quilt)' package means doing quilt
29 # fixup. Usually this involves recommitting the whole patch
30 # series, one at a time, with dpkg-source --commit. This is
31 # terribly terribly slow. (Maybe this should be fixed in dgit.)
33 # * dgit push usually needs to (re)make a pseudomerge. The "first"
34 # git-debrebase stripped out the previous pseudomerge and could
35 # have remembeed the HEAD. But it's not quite clear what history
36 # ought to be preserved and what should be discarded. For now
37 # the user will have to tell dgit --overwrite.
39 # To fix this, do we need a new push hook for dgit ?
41 # * Workflow is currently clumsy. Lots of spurious runes to type.
42 # There's not even a guide.
44 # * There are no tests.
46 # * new-upstream-v0 has a terrible UI. You end up with giant
47 # runic command lines.
49 # One consequence of the lack of richness it can need --force in
50 # fairly sensible situations and there is no way to tell it what
51 # you are really trying to do, other than just --force. There
52 # should be an interface with some default branch names.
54 # * There should be a standard convention for the version number,
55 # and unfinalised or not changelog, after new-upstream.
57 # * Handing of multi-orig dgit new-upstream .dsc imports is known to
58 # be broken. They may be not recognised, improperly converted, or
59 # their conversion may be unrecognised.
61 # * Docs need writing and updating. Even README.git-debrebase
62 # describes a design but may not reflect the implementation.
64 # * We need to develop a plausible model that works for derivatives,
65 # who probably want to maintain their stack on top of Debian's.
66 # downstream-rebase-launder-v0 may be a starting point?
70 use Debian::Dgit qw(:DEFAULT :playground);
77 use Getopt::Long qw(:config posix_default gnu_compat bundling);
79 use File::FnMatch qw(:fnmatch);
81 our ($opt_force, $opt_noop_ok, @opt_anchors);
83 our $us = qw(git-debrebase);
87 die "bad usage: $m\n";
91 my ($k, $optional) = @_;
93 my @cmd = qw(git config -z);
94 push @cmd, qw(--get-all) if wantarray;
96 my $out = cmdoutput_errok @cmd;
98 fail "missing required git config $k" unless $optional;
101 my @l = split /\0/, $out;
102 return wantarray ? @l : $l[0];
109 my $dd = new Data::Dumper [ $v ];
110 Terse $dd 1; Indent $dd 0; Useqq $dd 1;
116 my $data = (git_cat_file $objid, 'commit');
117 $data =~ m/(?<=\n)\n/ or die "$objid ($data) ?";
121 sub D_UPS () { 0x02; } # upstream files
122 sub D_PAT_ADD () { 0x04; } # debian/patches/ extra patches at end
123 sub D_PAT_OTH () { 0x08; } # debian/patches other changes
124 sub D_DEB_CLOG () { 0x10; } # debian/ (not patches/ or changelog)
125 sub D_DEB_OTH () { 0x20; } # debian/changelog
126 sub DS_DEB () { D_DEB_CLOG | D_DEB_OTH; } # debian/ (not patches/)
128 our $playprefix = 'debrebase';
134 sub in_workarea ($) {
137 my $r = eval { $sub->(); };
138 { local $@; changedir $maindir; }
142 sub fresh_workarea () {
143 $workarea = fresh_playground "$playprefix/work";
144 in_workarea sub { playtree_setup };
147 our @deferred_updates;
148 our @deferred_update_messages;
150 sub run_deferred_updates ($) {
153 my @upd_cmd = (@git, qw(update-ref --stdin -m), "debrebase: $mrest");
154 debugcmd '>|', @upd_cmd;
155 open U, "|-", @upd_cmd or die $!;
156 foreach (@deferred_updates) {
157 printdebug ">= ", $_, "\n";
158 print U $_, "\n" or die $!;
161 close U or failedcmd @upd_cmd;
163 print $_, "\n" foreach @deferred_update_messages;
165 @deferred_updates = ();
166 @deferred_update_messages = ();
169 sub get_differs ($$) {
171 # This resembles quiltify_trees_differ, in dgit, a bit.
172 # But we don't care about modes, or dpkg-source-unrepresentable
173 # changes, and we don't need the plethora of different modes.
174 # Conversely we need to distinguish different kinds of changes to
175 # debian/ and debian/patches/.
180 my ($opts, $limits, $fn) = @_;
181 my @cmd = (@git, qw(diff-tree -z --no-renames));
183 push @cmd, "$_:" foreach $x, $y;
184 push @cmd, '--', @$limits;
185 my $diffs = cmdoutput @cmd;
186 foreach (split /\0/, $diffs) { $fn->(); }
189 $rundiff->([qw(--name-only)], [], sub {
190 $differs |= $_ eq 'debian' ? DS_DEB : D_UPS;
193 if ($differs & DS_DEB) {
195 $rundiff->([qw(--name-only -r)], [qw(debian)], sub {
197 m{^debian/patches/} ? D_PAT_OTH :
198 $_ eq 'debian/changelog' ? D_DEB_CLOG :
201 die "mysterious debian changes $x..$y"
202 unless $differs & (D_PAT_OTH|DS_DEB);
205 if ($differs & D_PAT_OTH) {
207 $differs &= ~D_PAT_OTH;
209 $differs |= D_PAT_OTH;
210 no warnings qw(exiting); last;
212 $rundiff->([qw(--name-status -r)], [qw(debian/patches/)], sub {
213 no warnings qw(exiting);
214 if (!defined $mode) {
217 die unless s{^debian/patches/}{};
219 if ($mode eq 'A' && !m/\.series$/s) {
221 } elsif ($mode eq 'M' && $_ eq 'series') {
222 my $x_s = (git_cat_file "$x:debian/patches/series", 'blob');
223 my $y_s = (git_cat_file "$y:debian/patches/series", 'blob');
224 chomp $x_s; $x_s .= "\n";
225 $ok = $x_s eq substr($y_s, 0, length $x_s);
230 $differs |= $ok ? D_PAT_ADD : D_PAT_OTH;
232 die "mysterious debian/patches changes $x..$y"
233 unless $differs & (D_PAT_ADD|D_PAT_OTH);
236 printdebug sprintf "get_differs %s, %s = %#x\n", $x, $y, $differs;
241 sub commit_pr_info ($) {
243 return Data::Dumper->dump([$r], [qw(commit)]);
246 sub calculate_committer_authline () {
247 my $c = cmdoutput @git, qw(commit-tree --no-gpg-sign -m),
248 'DUMMY COMMIT (git-debrebase)', "HEAD:";
249 my ($h,$m) = get_commit $c;
250 $h =~ m/^committer .*$/m or confess "($h) ?";
254 sub rm_subdir_cached ($) {
256 runcmd @git, qw(rm --quiet -rf --cached --ignore-unmatch), $subdir;
259 sub read_tree_subdir ($$) {
260 my ($subdir, $new_tree_object) = @_;
261 rm_subdir_cached $subdir;
262 runcmd @git, qw(read-tree), "--prefix=$subdir/", $new_tree_object;
265 sub make_commit ($$) {
266 my ($parents, $message_paras) = @_;
267 my $tree = cmdoutput @git, qw(write-tree);
268 my @cmd = (@git, qw(commit-tree), $tree);
269 push @cmd, qw(-p), $_ foreach @$parents;
270 push @cmd, qw(-m), $_ foreach @$message_paras;
271 return cmdoutput @cmd;
274 our @fproblem_force_opts;
275 our $fproblems_forced;
276 our $fproblems_tripped;
279 if (grep { $_ eq $tag } @fproblem_force_opts) {
281 print STDERR "git-debrebase: safety catch overridden (-f$tag): $msg\n";
283 $fproblems_tripped++;
284 print STDERR "git-debrebase: safety catch tripped (-f$tag): $msg\n";
288 sub fproblems_maybe_bail () {
289 if ($fproblems_forced) {
291 "%s: safety catch trips: %d overriden by individual -f options\n",
292 $us, $fproblems_forced;
294 if ($fproblems_tripped) {
297 "%s: safety catch trips: %d overriden by global --force\n",
298 $us, $fproblems_tripped;
301 "%s: safety catch trips: %d blockers (you could -f<tag>, or --force)",
302 $us, $fproblems_tripped;
306 sub any_fproblems () {
307 return $fproblems_forced || $fproblems_tripped;
310 # classify returns an info hash like this
312 # Hdr => # commit headers, including 1 final newline
313 # Msg => # commit message (so one newline is dropped)
315 # Type => (see below)
317 # Ix => $index # ie 0, 1, 2, ...
319 # Differs => return value from get_differs
321 # IsDggitImport => 'orig' 'tarball' 'unpatched' 'package' (as from dgit)
323 # NewMsg => # commit message, but with any [dgit import ...] edited
324 # # to say "[was: ...]"
334 # has additional entres in classification result
335 # Overwritten = [ subset of Parents ]
336 # Contributor = $the_remaining_Parent
338 # DgitImportUnpatched
339 # has additional entry in classification result
340 # OrigParents = [ subset of Parents ]
343 # has additional entry in classification result
344 # OrigParents = [ subset of Parents ] # singleton list
351 # has additional entry in classification result
354 sub parsecommit ($;$) {
355 my ($objid, $p_ref) = @_;
356 # => hash with CommitId Hdr Msg Tree Parents
357 # Parents entries have only Ix CommitId
358 # $p_ref, if provided, must be [] and is used as a base for Parents
363 my ($h,$m) = get_commit $objid;
365 my ($t) = $h =~ m/^tree (\w+)$/m or die $objid;
366 my (@ph) = $h =~ m/^parent (\w+)$/mg;
376 foreach my $ph (@ph) {
378 Ix => scalar @$p_ref,
390 my $r = parsecommit($objid, \@p);
394 $p->{Differs} = (get_differs $p->{CommitId}, $t),
397 printdebug "classify $objid \$t=$t \@p",
398 (map { sprintf " %s/%#x", $_->{CommitId}, $_->{Differs} } @p),
402 my ($type, @rest) = @_;
403 $r = { %$r, Type => $type, @rest };
405 printdebug " = $type ".(dd $r)."\n";
411 $r = { %$r, Type => qw(Unknown), Why => $why };
412 printdebug " ** Unknown\n";
416 if (grep { $_ eq $objid } @opt_anchors) {
417 return $classify->('TreatAsAnchor');
420 my @identical = grep { !$_->{Differs} } @p;
421 my ($stype, $series) = git_cat_file "$t:debian/patches/series";
422 my $haspatches = $stype ne 'missing' && $series =~ m/^\s*[^#\n\t ]/m;
424 if ($r->{Msg} =~ m{^\[git-debrebase anchor.*\]$}m) {
425 # multi-orig upstreams are represented with an anchor merge
426 # from a single upstream commit which combines the orig tarballs
428 # Every anchor tagged this way must be a merge.
429 # We are relying on the
430 # [git-debrebase anchor: ...]
431 # commit message annotation in "declare" anchor merges (which
432 # do not have any upstream changes), to distinguish those
433 # anchor merges from ordinary pseudomerges (which we might
434 # just try to strip).
436 # However, the user is going to be doing git-rebase a lot. We
437 # really don't want them to rewrite an anchor commit.
438 # git-rebase trips up on merges, so that is a useful safety
441 # BreakwaterStart commits are also anchors in the terminology
442 # of git-debrebase(5), but they are untagged (and always
443 # manually generated).
445 my $badanchor = sub { $unknown->("git-debrebase \`anchor' but @_"); };
446 @p == 2 or return $badanchor->("has other than two parents");
447 $haspatches and return $badanchor->("contains debian/patches");
449 # How to decide about l/r ordering of anchors ? git
450 # --topo-order prefers to expand 2nd parent first. There's
451 # already an easy rune to look for debian/ history anyway (git log
452 # debian/) so debian breakwater branch should be 1st parent; that
453 # way also there's also an easy rune to look for the upstream
454 # patches (--topo-order).
456 $p[0]{IsOrigin} and $badanchor->("is an origin commit");
457 $p[1]{Differs} & ~DS_DEB and
458 $badanchor->("upstream files differ from left parent");
459 $p[0]{Differs} & ~D_UPS and
460 $badanchor->("debian/ differs from right parent");
462 return $classify->(qw(Anchor),
463 OrigParents => [ $p[1] ]);
467 my $d = $r->{Parents}[0]{Differs};
468 if ($d == D_PAT_ADD) {
469 return $classify->(qw(AddPatches));
470 } elsif ($d & (D_PAT_ADD|D_PAT_OTH)) {
471 return $unknown->("edits debian/patches");
472 } elsif ($d & DS_DEB and !($d & ~DS_DEB)) {
473 my ($ty,$dummy) = git_cat_file "$p[0]{CommitId}:debian";
475 if ($d == D_DEB_CLOG) {
476 return $classify->(qw(Changelog));
478 return $classify->(qw(Packaging));
480 } elsif ($ty eq 'missing') {
481 return $classify->(qw(BreakwaterStart));
483 return $unknown->("parent's debian is not a directory");
485 } elsif ($d == D_UPS) {
486 return $classify->(qw(Upstream));
487 } elsif ($d & DS_DEB and $d & D_UPS and !($d & ~(DS_DEB|D_UPS))) {
488 return $classify->(qw(Mixed));
490 return $unknown->("no changes");
492 confess "internal error $objid ?";
496 return $unknown->("origin commit");
499 if (@p == 2 && @identical == 1) {
500 my @overwritten = grep { $_->{Differs} } @p;
501 confess "internal error $objid ?" unless @overwritten==1;
502 return $classify->(qw(Pseudomerge),
503 Overwritten => [ $overwritten[0] ],
504 Contributor => $identical[0]);
506 if (@p == 2 && @identical == 2) {
508 my ($ph,$pm) = get_commit $_[0]{CommitId};
509 $ph =~ m/^committer .* (\d+) [-+]\d+$/m or die "$_->{CommitId} ?";
513 my $order = $get_t->($bytime[0]) <=> $get_t->($bytime[1]);
514 if ($order > 0) { # newer first
515 } elsif ($order < 0) {
516 @bytime = reverse @bytime;
518 # same age, default to order made by -s ours
519 # that is, commit was made by someone who preferred L
521 return $classify->(qw(Pseudomerge),
522 SubType => qw(Ambiguous),
523 Contributor => $bytime[0],
524 Overwritten => [ $bytime[1] ]);
527 my ($p_h, $p_m) = get_commit $p->{CommitId};
528 $p->{IsOrigin} = $p_h !~ m/^parent \w+$/m;
529 ($p->{IsDgitImport},) = $p_m =~ m/^\[dgit import ([0-9a-z]+) .*\]$/m;
531 my @orig_ps = grep { ($_->{IsDgitImport}//'X') eq 'orig' } @p;
533 if (!(grep { !$_->{IsOrigin} } @p) and
534 (@orig_ps >= @p - 1) and
535 $m2 =~ s{^\[(dgit import unpatched .*)\]$}{[was: $1]}m) {
537 return $classify->(qw(DgitImportUnpatched),
538 OrigParents => \@orig_ps);
541 return $unknown->("complex merge");
544 sub breakwater_of ($) {
545 my ($head) = @_; # must be laundered
549 fail "branch needs laundering (run git-debrebase): $why";
552 my $cl = classify $head;
553 my $ty = $cl->{Type};
554 if ($ty eq 'Packaging' or
555 $ty eq 'Changelog') {
556 $breakwater //= $head;
557 } elsif ($ty eq 'Anchor' or
558 $ty eq 'TreatAsAnchor' or
559 $ty eq 'BreakwaterStart') {
560 $breakwater //= $head;
562 } elsif ($ty eq 'Upstream') {
563 $unclean->("packaging change ($breakwater)".
564 " follows upstream change (eg $head)")
565 if defined $breakwater;
566 } elsif ($ty eq 'Mixed') {
567 $unclean->('found mixed upstream/packaging commit ($head)');
568 } elsif ($ty eq 'Pseudomerge' or
569 $ty eq 'AddPatches') {
570 $unclean->("found interchange conversion commit ($ty, $head)");
571 } elsif ($ty eq 'DgitImportUnpatched') {
572 $unclean->("found dgit dsc import ($head)");
574 fail "found unprocessable commit, cannot cope: $head; $cl->{Why}";
576 $head = $cl->{Parents}[0]{CommitId};
584 $nogenerate,$report) = @_;
585 # => ($tip, $breakwater_tip, $last_anchor)
586 # (or nothing, if $nogenerate)
588 printdebug "*** WALK $input ".($nogenerate//0)." ".($report//'-')."\n";
590 # go through commits backwards
591 # we generate two lists of commits to apply:
592 # breakwater branch and upstream patches
593 my (@brw_cl, @upp_cl, @processed);
600 my ($prose, $info) = @_;
604 $ms .= "\n\n[git-debrebase$info: $prose]\n";
607 my $rewrite_from_here = sub {
609 my $sp_cl = { SpecialMethod => 'StartRewrite' };
611 push @processed, $sp_cl;
616 my $prprdelim = sub { print $report $prdelim if $report; $prdelim=""; };
619 return unless $report;
620 print $report $prdelim, @_;
624 my $bomb = sub { # usage: return $bomb->();
625 print $report " Unprocessable" if $report;
626 print $report " ($cl->{Why})" if $report && defined $cl->{Why};
629 return (undef,undef);
631 die "commit $cur: Cannot cope with this commit (d.".
632 (join ' ', map { sprintf "%#x", $_->{Differs} }
633 @{ $cl->{Parents} }).
634 (defined $cl->{Why} ? "; $cl->{Why}": '').
641 my $build_start = sub {
642 my ($msg, $parent) = @_;
645 no warnings qw(exiting); last;
652 my $ty = $cl->{Type};
653 my $st = $cl->{SubType};
654 $prline->("$cl->{CommitId} $cl->{Type}");
655 $found{$ty. ( defined($st) ? "-$st" : '' )}++;
656 push @processed, $cl;
657 my $p0 = @{ $cl->{Parents} }==1 ? $cl->{Parents}[0]{CommitId} : undef;
658 if ($ty eq 'AddPatches') {
660 $rewrite_from_here->(\@upp_cl);
662 } elsif ($ty eq 'Packaging' or $ty eq 'Changelog') {
666 } elsif ($ty eq 'BreakwaterStart') {
668 $build_start->('FirstPackaging', $cur);
669 } elsif ($ty eq 'Upstream') {
673 } elsif ($ty eq 'Mixed') {
676 my $cls = { %$cl, $xmsg->("split mixed commit: $wh part") };
679 $queue->(\@brw_cl, "debian");
680 $queue->(\@upp_cl, "upstream");
681 $rewrite_from_here->(\@brw_cl);
684 } elsif ($ty eq 'Pseudomerge') {
685 my $contrib = $cl->{Contributor}{CommitId};
686 print $report " Contributor=$contrib" if $report;
687 push @pseudomerges, $cl;
688 $rewrite_from_here->(\@upp_cl);
691 } elsif ($ty eq 'Anchor' or $ty eq 'TreatAsAnchor') {
693 $build_start->("Anchor", $cur);
694 } elsif ($ty eq 'DgitImportUnpatched') {
695 my $pm = $pseudomerges[-1];
697 # To an extent, this is heuristic. Imports don't have
698 # a useful history of the debian/ branch. We assume
699 # that the first pseudomerge after an import has a
700 # useful history of debian/, and ignore the histories
701 # from later pseudomerges. Often the first pseudomerge
702 # will be the dgit import of the upload to the actual
703 # suite intended by the non-dgit NMUer, and later
704 # pseudomerges may represent in-archive copies.
705 my $ovwrs = $pm->{Overwritten};
706 printf $report " PM=%s \@Overwr:%d",
707 $pm->{CommitId}, (scalar @$ovwrs)
710 printdebug "*** WALK BOMB DgitImportUnpatched\n";
713 my $ovwr = $ovwrs->[0]{CommitId};
714 printf $report " Overwr=%s", $ovwr if $report;
715 # This import has a tree which is just like a
716 # breakwater tree, but it has the wrong history. It
717 # ought to have the previous breakwater (which the
718 # pseudomerge overwrote) as an ancestor. That will
719 # make the history of the debian/ files correct. As
720 # for the upstream version: either it's the same as
721 # was ovewritten (ie, same as the previous
722 # breakwater), in which case that history is precisely
723 # right; or, otherwise, it was a non-gitish upload of a
724 # new upstream version. We can tell these apart by
725 # looking at the tree of the supposed upstream.
728 SpecialMethod => 'DgitImportDebianUpdate',
729 $xmsg->("convert dgit import: debian changes")
732 SpecialMethod => 'DgitImportUpstreamUpdate',
733 $xmsg->("convert dgit import: upstream update",
736 $prline->(" Import");
737 $rewrite_from_here->(\@brw_cl);
738 $upp_limit //= $#upp_cl; # further, deeper, patches discarded
742 # Everything is from this import. This kind of import
743 # is already in valid breakwater format, with the
744 # patches as commits.
745 printf $report " NoPM" if $report;
746 # last thing we processed will have been the first patch,
747 # if there is one; which is fine, so no need to rewrite
748 # on account of this import
749 $build_start->("ImportOrigin", $cur);
753 printdebug "*** WALK BOMB unrecognised\n";
759 printdebug "*** WALK prep done cur=$cur".
760 " brw $#brw_cl upp $#upp_cl proc $#processed pm $#pseudomerges\n";
762 return if $nogenerate;
764 # Now we build it back up again
770 my $read_tree_debian = sub {
772 read_tree_subdir 'debian', "$treeish:debian";
773 rm_subdir_cached 'debian/patches';
775 my $read_tree_upstream = sub {
777 runcmd @git, qw(read-tree), $treeish;
778 $read_tree_debian->($build);
781 $#upp_cl = $upp_limit if defined $upp_limit;
783 my $committer_authline = calculate_committer_authline();
785 printdebug "WALK REBUILD $build ".(scalar @processed)."\n";
787 confess "internal error" unless $build eq (pop @processed)->{CommitId};
790 mkdir $rd or $!==EEXIST or die $!;
792 runcmd @git, qw(read-tree), $build;
793 foreach my $cl (qw(Debian), (reverse @brw_cl),
794 { SpecialMethod => 'RecordBreakwaterTip' },
795 qw(Upstream), (reverse @upp_cl)) {
797 $current_method = $cl;
800 my $method = $cl->{SpecialMethod} // $current_method;
801 my @parents = ($build);
802 my $cltree = $cl->{CommitId};
803 printdebug "WALK BUILD ".($cltree//'undef').
804 " $method (rewriting=$rewriting)\n";
805 if ($method eq 'Debian') {
806 $read_tree_debian->($cltree);
807 } elsif ($method eq 'Upstream') {
808 $read_tree_upstream->($cltree);
809 } elsif ($method eq 'StartRewrite') {
812 } elsif ($method eq 'RecordBreakwaterTip') {
813 $breakwater = $build;
815 } elsif ($method eq 'DgitImportDebianUpdate') {
816 $read_tree_debian->($cltree);
817 } elsif ($method eq 'DgitImportUpstreamUpdate') {
818 confess unless $rewriting;
819 my $differs = (get_differs $build, $cltree);
820 next unless $differs & D_UPS;
821 $read_tree_upstream->($cltree);
822 push @parents, map { $_->{CommitId} } @{ $cl->{OrigParents} };
827 my $procd = (pop @processed) // 'UNDEF';
830 printdebug "WALK REWRITING NOW cl=$cl procd=$procd\n";
833 my $newtree = cmdoutput @git, qw(write-tree);
835 $ch =~ s{^tree .*}{tree $newtree}m or confess "$ch ?";
836 $ch =~ s{^parent .*\n}{}mg;
837 $ch =~ s{(?=^author)}{
838 join '', map { "parent $_\n" } @parents
839 }me or confess "$ch ?";
841 $ch =~ s{^committer .*$}{$committer_authline}m
844 my $cf = "$rd/m$rewriting";
845 open CD, ">", $cf or die $!;
846 print CD $ch, "\n", $cl->{Msg} or die $!;
848 my @cmd = (@git, qw(hash-object));
849 push @cmd, qw(-w) if $rewriting;
850 push @cmd, qw(-t commit), $cf;
851 my $newcommit = cmdoutput @cmd;
852 confess "$ch ?" unless $rewriting or $newcommit eq $cl->{CommitId};
854 if (grep { $method eq $_ } qw(DgitImportUpstreamUpdate)) {
860 my $final_check = get_differs $build, $input;
861 die sprintf "internal error %#x %s %s", $final_check, $build, $input
862 if $final_check & ~D_PAT_ADD;
864 my @r = ($build, $breakwater, $last_anchor);
865 printdebug "*** WALK RETURN @r\n";
870 git_check_unmodified();
871 return git_rev_parse qw(HEAD);
874 sub update_head ($$$) {
875 my ($old, $new, $mrest) = @_;
876 push @deferred_updates, "update HEAD $new $old";
877 run_deferred_updates $mrest;
880 sub update_head_checkout ($$$) {
881 my ($old, $new, $mrest) = @_;
882 update_head $old, $new, $mrest;
883 runcmd @git, qw(reset --hard);
886 sub update_head_postlaunder ($$$) {
887 my ($old, $tip, $reflogmsg) = @_;
888 return if $tip eq $old;
889 print "git-debrebase: laundered (head was $old)\n";
890 update_head $old, $tip, $reflogmsg;
891 # no tree changes except debian/patches
892 runcmd @git, qw(rm --quiet --ignore-unmatch -rf debian/patches);
895 sub cmd_launder_v0 () {
896 badusage "no arguments to launder-v0 allowed" if @ARGV;
897 my $old = get_head();
898 my ($tip,$breakwater,$last_anchor) = walk $old;
899 update_head_postlaunder $old, $tip, 'launder';
900 printf "# breakwater tip\n%s\n", $breakwater;
901 printf "# working tip\n%s\n", $tip;
902 printf "# last anchor\n%s\n", $last_anchor;
905 sub defaultcmd_rebase () {
906 my $old = get_head();
908 my ($tip,$breakwater) = walk $old;
909 update_head_postlaunder $old, $tip, 'launder for rebase';
910 runcmd @git, qw(rebase), @ARGV, $breakwater;
914 die if ($ARGV[0]//'') =~ m/^-/;
915 badusage "too many arguments to analyse" if @ARGV>1;
918 $old = git_rev_parse $old;
920 $old = git_rev_parse 'HEAD';
922 my ($dummy,$breakwater) = walk $old, 1,*STDOUT;
923 STDOUT->error and die $!;
926 sub ffq_prev_branchinfo () {
927 # => ('status', "message", [$current, $ffq_prev])
929 # branch message is undef
930 # weird-symref } no $current,
931 # notbranch } no $ffq_prev
932 my $current = git_get_symref();
933 return ('detached', 'detached HEAD') unless defined $current;
934 return ('weird-symref', 'HEAD symref is not to refs/')
935 unless $current =~ m{^refs/};
936 my $ffq_prev = "refs/$ffq_refprefix/$'";
937 printdebug "ffq_prev_branchinfo branch current $current\n";
938 return ('branch', undef, $current, $ffq_prev);
941 sub record_ffq_prev_deferred () {
942 # => ('status', "message")
944 # deferred message is undef
949 # if not ff from some branch we should be ff from, is an fproblem
950 # if "deferred", will have added something about that to
951 # @deferred_update_messages, and also maybe printed (already)
952 # some messages about ff checks
953 my ($status, $message, $current, $ffq_prev) = ffq_prev_branchinfo();
954 return ($status, $message) unless $status eq 'branch';
956 my $currentval = get_head();
958 my $exists = git_get_ref $ffq_prev;
959 return ('exists',"$ffq_prev already exists") if $exists;
961 return ('not-branch', 'HEAD symref is not to refs/heads/')
962 unless $current =~ m{^refs/heads/};
965 my @check_specs = split /\;/, (cfg "branch.$branch.ffq-ffrefs",1) // '*';
968 printdebug "ffq check_specs @check_specs\n";
971 my ($lrref, $desc) = @_;
972 printdebug "ffq might check $lrref ($desc)\n";
974 for my $chk (@check_specs) {
976 $invert = $glob =~ s{^[!^]}{};
977 last if fnmatch $glob, $lrref;
980 my $lrval = git_get_ref $lrref;
981 return unless defined $lrval;
983 if (is_fast_fwd $lrval, $currentval) {
984 print "OK, you are ahead of $lrref\n" or die $!;
985 $checked{$lrref} = 1;
986 } elsif (is_fast_fwd $currentval, $lrval) {
987 $checked{$lrref} = -1;
988 fproblem 'behind', "you are behind $lrref, divergence risk";
990 $checked{$lrref} = -1;
991 fproblem 'diverged', "you have diverged from $lrref";
995 my $merge = cfg "branch.$branch.merge",1;
996 if (defined $merge and $merge =~ m{^refs/heads/}) {
998 printdebug "ffq merge $rhs\n";
999 my $check_remote = sub {
1000 my ($remote, $desc) = @_;
1001 printdebug "ffq check_remote ".($remote//'undef')." $desc\n";
1002 return unless defined $remote;
1003 $check->("refs/remotes/$remote/$rhs", $desc);
1005 $check_remote->((scalar cfg "branch.$branch.remote",1),
1006 'remote fetch/merge branch');
1007 $check_remote->((scalar cfg "branch.$branch.pushRemote",1) //
1008 (scalar cfg "branch.$branch.pushDefault",1),
1009 'remote push branch');
1011 if ($branch =~ m{^dgit/}) {
1012 $check->("refs/remotes/dgit/$branch", 'remote dgit branch');
1013 } elsif ($branch =~ m{^master$}) {
1014 $check->("refs/remotes/dgit/dgit/sid", 'remote dgit branch for sid');
1017 fproblems_maybe_bail();
1019 push @deferred_updates, "update $ffq_prev $currentval $git_null_obj";
1020 push @deferred_update_messages, "Recorded current head for preservation";
1021 return ('deferred', undef);
1024 sub record_ffq_auto () {
1025 my ($status, $message) = record_ffq_prev_deferred();
1026 if ($status eq 'deferred' || $status eq 'exists') {
1028 fproblem $status, "could not record ffq-prev: $message";
1029 fproblems_maybe_bail();
1033 sub cmd_new_upstream_v0 () {
1034 # automatically and unconditionally launders before rebasing
1035 # if rebase --abort is used, laundering has still been done
1039 badusage "need NEW-VERSION [UPS-COMMITTISH]" unless @ARGV >= 1;
1041 # parse args - low commitment
1042 my $new_version = (new Dpkg::Version scalar(shift @ARGV), check => 1);
1043 my $new_upstream_version = $new_version->version();
1045 my $new_upstream = git_rev_parse (shift @ARGV // 'upstream');
1050 my ($n, @x) = @_; # may be ''
1051 my $pc = $pieces{$n} //= {
1053 Desc => ($n ? "upstream piece \`$n'" : "upstream (main piece"),
1055 while (my $k = shift @x) { $pc->{$k} = shift @x; }
1060 my $newpiece = sub {
1061 my ($n, @x) = @_; # may be ''
1062 my $pc = $piece->($n, @x, NewIx => (scalar @newpieces));
1063 push @newpieces, $pc;
1068 New => $new_upstream,
1070 while (@ARGV && $ARGV[0] !~ m{^-}) {
1071 my $n = shift @ARGV;
1073 badusage "for each EXTRA-UPS-NAME need EXTRA-UPS-COMMITISH"
1074 unless @ARGV && $ARGV[0] !~ m{^-};
1076 my $c = git_rev_parse shift @ARGV;
1077 die unless $n =~ m/^$extra_orig_namepart_re$/;
1078 $newpiece->($n, New => $c);
1081 # now we need to investigate the branch this generates the
1082 # laundered version but we don't switch to it yet
1083 my $old_head = get_head();
1084 my ($old_laundered_tip,$old_bw,$old_anchor) = walk $old_head;
1086 my $old_bw_cl = classify $old_bw;
1087 my $old_anchor_cl = classify $old_anchor;
1089 if (!$old_anchor_cl->{OrigParents}) {
1090 fproblem 'anchor-treated',
1091 'old anchor is recognised due to --anchor, cannot check upstream';
1093 $old_upstream = parsecommit
1094 $old_anchor_cl->{OrigParents}[0]{CommitId};
1095 $piece->('', Old => $old_upstream->{CommitId});
1098 if ($old_upstream && $old_upstream->{Msg} =~ m{^\[git-debrebase }m) {
1099 if ($old_upstream->{Msg} =~
1100 m{^\[git-debrebase upstream-combine \.((?: $extra_orig_namepart_re)+)\:.*\]$}m
1102 my @oldpieces = ('', split / /, $1);
1103 my $parentix = -1 + scalar @{ $old_upstream->{Parents} };
1104 foreach my $i (0..$#oldpieces) {
1105 my $n = $oldpieces[$i];
1106 $piece->($n, Old => $old_upstream->{CommitId}.'^'.$parentix);
1109 fproblem 'upstream-confusing',
1110 "previous upstream $old_upstream->{CommitId} is from".
1111 " git-debrebase but not an \`upstream-combine' commit";
1115 foreach my $pc (values %pieces) {
1116 if (!$old_upstream) {
1117 # we have complained already
1118 } elsif (!$pc->{Old}) {
1119 fproblem 'upstream-new-piece',
1120 "introducing upstream piece \`$pc->{Name}'";
1121 } elsif (!$pc->{New}) {
1122 fproblem 'upstream-rm-piece',
1123 "dropping upstream piece \`$pc->{Name}'";
1124 } elsif (!is_fast_fwd $pc->{Old}, $pc->{New}) {
1125 fproblem 'upstream-not-ff',
1126 "not fast forward: $pc->{Name} $pc->{Old}..$pc->{New}";
1130 printdebug "%pieces = ", (dd \%pieces), "\n";
1131 printdebug "\@newpieces = ", (dd \@newpieces), "\n";
1133 fproblems_maybe_bail();
1139 my @upstream_merge_parents;
1141 if (!any_fproblems()) {
1142 push @upstream_merge_parents, $old_upstream->{CommitId};
1145 foreach my $pc (@newpieces) { # always has '' first
1147 read_tree_subdir $pc->{Name}, $pc->{New};
1149 runcmd @git, qw(read-tree), $pc->{New};
1151 push @upstream_merge_parents, $pc->{New};
1154 # index now contains the new upstream
1156 if (@newpieces > 1) {
1157 # need to make the upstream subtree merge commit
1158 $new_upstream = make_commit \@upstream_merge_parents,
1159 [ "Combine upstreams for $new_upstream_version",
1160 ("[git-debrebase upstream-combine . ".
1161 (join " ", map { $_->{Name} } @newpieces[1..$#newpieces]).
1166 # $new_upstream is either the single upstream commit, or the
1167 # combined commit we just made. Either way it will be the
1168 # "upstream" parent of the anchor merge.
1170 read_tree_subdir 'debian', "$old_bw:debian";
1172 # index now contains the anchor merge contents
1173 $new_bw = make_commit [ $old_bw, $new_upstream ],
1174 [ "Update to upstream $new_upstream_version",
1175 "[git-debrebase anchor: new upstream $new_upstream_version, merge]",
1178 # Now we have to add a changelog stanza so the Debian version
1180 die if unlink "debian";
1181 die $! unless $!==ENOENT or $!==ENOTEMPTY;
1182 unlink "debian/changelog" or $!==ENOENT or die $!;
1183 mkdir "debian" or die $!;
1184 open CN, ">", "debian/changelog" or die $!;
1185 my $oldclog = git_cat_file ":debian/changelog";
1186 $oldclog =~ m/^($package_re) \(\S+\) / or
1187 fail "cannot parse old changelog to get package name";
1189 print CN <<END, $oldclog or die $!;
1190 $p ($new_version) UNRELEASED; urgency=medium
1192 * Update to new upstream version $new_upstream_version.
1198 runcmd @git, qw(update-index --add --replace), 'debian/changelog';
1200 # Now we have the final new breakwater branch in the index
1201 $new_bw = make_commit [ $new_bw ],
1202 [ "Update changelog for new upstream $new_upstream_version",
1203 "[git-debrebase: new upstream $new_upstream_version, changelog]",
1207 # we have constructed the new breakwater. we now need to commit to
1208 # the laundering output, because git-rebase can't easily be made
1209 # to make a replay list which is based on some other branch
1211 update_head_postlaunder $old_head, $old_laundered_tip,
1212 'launder for new upstream';
1214 my @cmd = (@git, qw(rebase --onto), $new_bw, $old_bw, @ARGV);
1216 # now it's for the user to sort out
1219 sub cmd_record_ffq_prev () {
1220 badusage "no arguments allowed" if @ARGV;
1221 my ($status, $msg) = record_ffq_prev_deferred();
1222 if ($status eq 'exists' && $opt_noop_ok) {
1223 print "Previous head already recorded\n" or die $!;
1224 } elsif ($status eq 'deferred') {
1225 run_deferred_updates 'record-ffq-prev';
1227 fail "Could not preserve: $msg";
1231 sub cmd_breakwater () {
1232 badusage "no arguments allowed" if @ARGV;
1233 my $bw = breakwater_of git_rev_parse 'HEAD';
1234 print "$bw\n" or die $!;
1239 GetOptions('prose=s', \$prose) or die badusage("bad options to stitch");
1240 badusage "no arguments allowed" if @ARGV;
1241 my ($status, $message, $current, $ffq_prev) = ffq_prev_branchinfo();
1242 if ($status ne 'branch') {
1243 fproblem $status, "could not check ffq-prev: $message";
1244 fproblems_maybe_bail();
1246 my $prev = $ffq_prev && git_get_ref $ffq_prev;
1248 fail "No ffq-prev to stitch." unless $opt_noop_ok;
1250 push @deferred_updates, "delete $ffq_prev $prev";
1252 my $old_head = get_head();
1253 if (is_fast_fwd $old_head, $prev) {
1254 my $differs = get_differs $old_head, $prev;
1255 unless ($differs & ~D_PAT_ADD) {
1256 # ffq-prev is ahead of us, and the only tree changes it has
1257 # are possibly addition of things in debian/patches/.
1258 # Just wind forwards rather than making a pointless pseudomerge.
1259 update_head_checkout $old_head, $prev, "stitch (fast forward)";
1264 my $new_head = make_commit [ $old_head, $ffq_prev ], [
1265 'Declare fast forward / record previous work',
1266 "[git-debrebase pseudomerge: stitch$prose]",
1268 update_head $old_head, $new_head, "stitch";
1271 sub cmd_convert_from_gbp () {
1272 badusage "needs 1 optional argument, the upstream git rev"
1274 my ($upstream_spec) = @ARGV;
1275 $upstream_spec //= 'refs/heads/upstream';
1276 my $upstream = git_rev_parse $upstream_spec;
1277 my $old_head = get_head();
1279 my $upsdiff = get_differs $upstream, $old_head;
1280 if ($upsdiff & D_UPS) {
1281 runcmd @git, qw(--no-pager diff),
1282 $upstream, $old_head,
1283 qw( -- :!/debian :/);
1284 fail "upstream ($upstream_spec) and HEAD are not identical in upstream files";
1287 if (!is_fast_fwd $upstream, $old_head) {
1288 fproblem 'upstream-not-ancestor',
1289 "upstream ($upstream) is not an ancestor of HEAD";
1291 my $wrong = cmdoutput
1292 (@git, qw(rev-list --ancestry-path), "$upstream..HEAD",
1293 qw(-- :/ :!/debian));
1294 if (length $wrong) {
1295 fproblem 'unexpected-upstream-changes',
1296 "history between upstream ($upstream) and HEAD contains direct changes to upstream files - are you sure this is a gbp (patches-unapplied) branch?";
1297 print STDERR "list expected changes with: git log --stat --ancestry-path $upstream_spec..HEAD -- :/ ':!/debian'\n";
1301 if ((git_cat_file "$upstream:debian")[0] ne 'missing') {
1302 fproblem 'upstream-has-debian',
1303 "upstream ($upstream) contains debian/ directory";
1306 fproblems_maybe_bail();
1312 runcmd @git, qw(checkout -q -b gdr-internal), $old_head;
1313 # make a branch out of the patch queue - we'll want this in a mo
1314 runcmd qw(gbp pq import);
1315 # strip the patches out
1316 runcmd @git, qw(checkout -q gdr-internal~0);
1317 rm_subdir_cached 'debian/patches';
1318 $work = make_commit ['HEAD'], [
1319 'git-debrebase convert-from-gbp: drop patches from tree',
1320 'Delete debian/patches, as part of converting to git-debrebase format.',
1321 '[git-debrebase convert-from-gbp: drop patches from tree]'
1323 # make the anchor merge
1324 # the tree is already exactly right
1325 $work = make_commit [$work, $upstream], [
1326 'git-debrebase import: declare upstream',
1327 'First breakwater merge.',
1328 '[git-debrebase anchor: declare upstream]'
1331 # rebase the patch queue onto the new breakwater
1332 runcmd @git, qw(reset --quiet --hard patch-queue/gdr-internal);
1333 runcmd @git, qw(rebase --quiet --onto), $work, qw(gdr-internal);
1334 $work = git_rev_parse 'HEAD';
1337 update_head_checkout $old_head, $work, 'convert-from-gbp';
1340 sub cmd_convert_to_gbp () {
1341 badusage "no arguments allowed" if @ARGV;
1342 my $head = get_head();
1343 my $ffq = (ffq_prev_branchinfo())[3];
1344 my $bw = breakwater_of $head;
1348 runcmd @git, qw(checkout -q -b bw), $bw;
1349 runcmd @git, qw(checkout -q -b patch-queue/bw), $head;
1350 runcmd qw(gbp pq export);
1351 runcmd @git, qw(add debian/patches);
1352 $out = make_commit ['HEAD'], [
1353 'Commit patch queue (converted from git-debrebase format)',
1354 '[git-debrebase convert-to-gbp: commit patches]',
1358 push @deferred_updates, "delete $ffq";
1360 update_head_checkout $head, $out, "convert to gbp (v0)";
1361 print <<END or die $!;
1362 git-debrebase: converted to git-buildpackage branch format
1363 git-debrebase: WARNING: do not now run "git-debrebase" any more
1364 git-debrebase: WARNING: doing so would drop all upstream patches!
1368 sub cmd_downstream_rebase_launder_v0 () {
1369 badusage "needs 1 argument, the baseline" unless @ARGV==1;
1371 $base = git_rev_parse $base;
1372 my $old_head = get_head();
1373 my $current = $old_head;
1376 if ($current eq $base) {
1377 $topmost_keep //= $current;
1378 print " $current BASE stop\n";
1381 my $cl = classify $current;
1382 print " $current $cl->{Type}";
1384 my $p0 = $cl->{Parents}[0]{CommitId};
1386 if ($cl->{Type} eq 'Pseudomerge') {
1387 print " ^".($cl->{Contributor}{Ix}+1);
1388 $next = $cl->{Contributor}{CommitId};
1389 } elsif ($cl->{Type} eq 'AddPatches' or
1390 $cl->{Type} eq 'Changelog') {
1400 $topmost_keep //= $current;
1402 die "to-be stripped changes not on top of the branch\n"
1407 if ($topmost_keep eq $old_head) {
1408 print "unchanged\n";
1410 print "updating to $topmost_keep\n";
1411 update_head_checkout
1412 $old_head, $topmost_keep,
1413 'downstream-rebase-launder-v0';
1417 GetOptions("D+" => \$debuglevel,
1418 'noop-ok', => \$opt_noop_ok,
1419 'f=s' => \@fproblem_force_opts,
1420 'anchor=s' => \@opt_anchors,
1421 'force!') or die badusage "bad options\n";
1422 initdebug('git-debrebase ');
1423 enabledebug if $debuglevel;
1425 my $toplevel = cmdoutput @git, qw(rev-parse --show-toplevel);
1426 chdir $toplevel or die "chdir $toplevel: $!";
1428 $rd = fresh_playground "$playprefix/misc";
1430 @opt_anchors = map { git_rev_parse $_ } @opt_anchors;
1432 if (!@ARGV || $ARGV[0] =~ m{^-}) {
1433 defaultcmd_rebase();
1435 my $cmd = shift @ARGV;
1438 $cmdfn = ${*::}{"cmd_$cmdfn"};
1440 $cmdfn or badusage "unknown git-debrebase sub-operation $cmd";