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>] stitch [--prose=<for commit message>]
33 # git-debrebase [<options>] downstream-rebase-launder-v0 # experimental
35 # git-debrebase [<options>] convert-from-gbp <upstream-git-rev>
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);
90 use File::FnMatch qw(:fnmatch);
92 our ($opt_force, $opt_noop_ok);
94 our $us = qw(git-debrebase);
98 die "bad usage: $m\n";
102 my ($k, $optional) = @_;
104 my @cmd = qw(git config -z);
105 push @cmd, qw(--get-all) if wantarray;
107 my $out = cmdoutput_errok @cmd;
109 fail "missing required git config $k" unless $optional;
112 return split /\0/, $out;
119 my $dd = new Data::Dumper [ $v ];
120 Terse $dd 1; Indent $dd 0; Useqq $dd 1;
126 my $data = (git_cat_file $objid, 'commit');
127 $data =~ m/(?<=\n)\n/ or die "$objid ($data) ?";
131 sub D_UPS () { 0x02; } # upstream files
132 sub D_PAT_ADD () { 0x04; } # debian/patches/ extra patches at end
133 sub D_PAT_OTH () { 0x08; } # debian/patches other changes
134 sub D_DEB_CLOG () { 0x10; } # debian/ (not patches/ or changelog)
135 sub D_DEB_OTH () { 0x20; } # debian/changelog
136 sub DS_DEB () { D_DEB_CLOG | D_DEB_OTH; } # debian/ (not patches/)
138 our $playprefix = 'debrebase';
144 sub in_workarea ($) {
147 my $r = eval { $sub->(); };
148 { local $@; changedir $maindir; }
152 sub fresh_workarea () {
153 $workarea = fresh_playground "$playprefix/work";
154 in_workarea sub { playtree_setup };
157 sub get_differs ($$) {
159 # This resembles quiltify_trees_differ, in dgit, a bit.
160 # But we don't care about modes, or dpkg-source-unrepresentable
161 # changes, and we don't need the plethora of different modes.
162 # Conversely we need to distinguish different kinds of changes to
163 # debian/ and debian/patches/.
168 my ($opts, $limits, $fn) = @_;
169 my @cmd = (@git, qw(diff-tree -z --no-renames));
171 push @cmd, "$_:" foreach $x, $y;
172 push @cmd, '--', @$limits;
173 my $diffs = cmdoutput @cmd;
174 foreach (split /\0/, $diffs) { $fn->(); }
177 $rundiff->([qw(--name-only)], [], sub {
178 $differs |= $_ eq 'debian' ? DS_DEB : D_UPS;
181 if ($differs & DS_DEB) {
183 $rundiff->([qw(--name-only -r)], [qw(debian)], sub {
185 m{^debian/patches/} ? D_PAT_OTH :
186 $_ eq 'debian/changelog' ? D_DEB_CLOG :
189 die "mysterious debian changes $x..$y"
190 unless $differs & (D_PAT_OTH|DS_DEB);
193 if ($differs & D_PAT_OTH) {
195 $differs &= ~D_PAT_OTH;
197 $differs |= D_PAT_OTH;
198 no warnings qw(exiting); last;
200 $rundiff->([qw(--name-status -r)], [qw(debian/patches/)], sub {
201 no warnings qw(exiting);
202 if (!defined $mode) {
205 die unless s{^debian/patches/}{};
207 if ($mode eq 'A' && !m/\.series$/s) {
209 } elsif ($mode eq 'M' && $_ eq 'series') {
210 my $x_s = (git_cat_file "$x:debian/patches/series", 'blob');
211 my $y_s = (git_cat_file "$y:debian/patches/series", 'blob');
212 chomp $x_s; $x_s .= "\n";
213 $ok = $x_s eq substr($y_s, 0, length $x_s);
218 $differs |= $ok ? D_PAT_ADD : D_PAT_OTH;
220 die "mysterious debian/patches changes $x..$y"
221 unless $differs & (D_PAT_ADD|D_PAT_OTH);
224 printdebug sprintf "get_differs %s, %s = %#x\n", $x, $y, $differs;
229 sub commit_pr_info ($) {
231 return Data::Dumper->dump([$r], [qw(commit)]);
234 sub calculate_committer_authline () {
235 my $c = cmdoutput @git, qw(commit-tree --no-gpg-sign -m),
236 'DUMMY COMMIT (git-debrebase)', "HEAD:";
237 my ($h,$m) = get_commit $c;
238 $h =~ m/^committer .*$/m or confess "($h) ?";
242 sub rm_subdir_cached ($) {
244 runcmd @git, qw(rm --quiet -rf --cached --ignore-unmatch), $subdir;
247 sub read_tree_subdir ($$) {
248 my ($subdir, $new_tree_object) = @_;
249 rm_subdir_cached $subdir;
250 runcmd @git, qw(read-tree), "--prefix=$subdir/", $new_tree_object;
253 sub make_commit ($$) {
254 my ($parents, $message_paras) = @_;
255 my $tree = cmdoutput @git, qw(write-tree);
256 my @cmd = (@git, qw(commit-tree), $tree);
257 push @cmd, qw(-p), $_ foreach @$parents;
258 push @cmd, qw(-m), $_ foreach @$message_paras;
259 return cmdoutput @cmd;
262 our @fproblem_force_opts;
263 our $fproblems_forced;
264 our $fproblems_tripped;
267 if (grep { $_ eq $tag } @fproblem_force_opts) {
269 print STDERR "git-debrebase: safety catch overridden (-f$tag): $msg\n";
271 $fproblems_tripped++;
272 print STDERR "git-debrebase: safety catch tripped (-f$tag): $msg\n";
276 sub fproblems_maybe_bail () {
277 if ($fproblems_forced) {
279 "%s: safety catch trips: %d overriden by individual -f options\n",
280 $us, $fproblems_forced;
282 if ($fproblems_tripped) {
285 "%s: safety catch trips: %d overriden by global --force\n",
286 $us, $fproblems_tripped;
289 "%s: safety catch trips: %d blockers (you could -f<tag>, or --force)",
290 $us, $fproblems_tripped;
294 sub any_fproblems () {
295 return $fproblems_forced || $fproblems_tripped;
298 # classify returns an info hash like this
300 # Hdr => # commit headers, including 1 final newline
301 # Msg => # commit message (so one newline is dropped)
303 # Type => (see below)
305 # Ix => $index # ie 0, 1, 2, ...
307 # Differs => return value from get_differs
309 # IsDggitImport => 'orig' 'tarball' 'unpatched' 'package' (as from dgit)
311 # NewMsg => # commit message, but with any [dgit import ...] edited
312 # # to say "[was: ...]"
322 # has additional entres in classification result
323 # Overwritten = [ subset of Parents ]
324 # Contributor = $the_remaining_Parent
326 # DgitImportUnpatched
327 # has additional entry in classification result
328 # OrigParents = [ subset of Parents ]
330 # BreakwaterUpstreamMerge
331 # has additional entry in classification result
332 # OrigParents = [ subset of Parents ] # singleton list
335 # has additional entry in classification result
338 sub parsecommit ($;$) {
339 my ($objid, $p_ref) = @_;
340 # => hash with CommitId Hdr Msg Tree Parents
341 # Parents entries have only Ix CommitId
342 # $p_ref, if provided, must be [] and is used as a base for Parents
347 my ($h,$m) = get_commit $objid;
349 my ($t) = $h =~ m/^tree (\w+)$/m or die $objid;
350 my (@ph) = $h =~ m/^parent (\w+)$/mg;
360 foreach my $ph (@ph) {
362 Ix => scalar @$p_ref,
374 my $r = parsecommit($objid, \@p);
378 $p->{Differs} = (get_differs $p->{CommitId}, $t),
381 printdebug "classify $objid \$t=$t \@p",
382 (map { sprintf " %s/%#x", $_->{CommitId}, $_->{Differs} } @p),
386 my ($type, @rest) = @_;
387 $r = { %$r, Type => $type, @rest };
389 printdebug " = $type ".(dd $r)."\n";
395 $r = { %$r, Type => qw(Unknown), Why => $why };
396 printdebug " ** Unknown\n";
400 my $claims_to_be_breakwater =
401 $r->{Msg} =~ m{^\[git-debrebase breakwater.*\]$}m;
404 if ($claims_to_be_breakwater) {
405 return $unknown->("single-parent git-debrebase breakwater \`merge'");
407 my $d = $r->{Parents}[0]{Differs};
408 if ($d == D_PAT_ADD) {
409 return $classify->(qw(AddPatches));
410 } elsif ($d & (D_PAT_ADD|D_PAT_OTH)) {
411 return $unknown->("edits debian/patches");
412 } elsif ($d & DS_DEB and !($d & ~DS_DEB)) {
413 my ($ty,$dummy) = git_cat_file "$p[0]{CommitId}:debian";
415 if ($d == D_DEB_CLOG) {
416 return $classify->(qw(Changelog));
418 return $classify->(qw(Packaging));
420 } elsif ($ty eq 'missing') {
421 return $classify->(qw(BreakwaterStart));
423 return $unknown->("parent's debian is not a directory");
425 } elsif ($d == D_UPS) {
426 return $classify->(qw(Upstream));
427 } elsif ($d & DS_DEB and $d & D_UPS and !($d & ~(DS_DEB|D_UPS))) {
428 return $classify->(qw(Mixed));
430 return $unknown->("no changes");
432 confess "internal error $objid ?";
436 return $unknown->("origin commit");
439 my @identical = grep { !$_->{Differs} } @p;
440 if (@p == 2 && @identical == 1 && !$claims_to_be_breakwater
441 # breakwater merges can look like pseudomerges, if they are
442 # "declare" commits (ie, there are no upstream changes)
444 my @overwritten = grep { $_->{Differs} } @p;
445 confess "internal error $objid ?" unless @overwritten==1;
446 return $classify->(qw(Pseudomerge),
447 Overwritten => [ $overwritten[0] ],
448 Contributor => $identical[0]);
450 if (@p == 2 && @identical == 2) {
451 my @bytime = nsort_by {
452 my ($ph,$pm) = get_commit $_->{CommitId};
453 $ph =~ m/^committer .* (\d+) [-+]\d+$/m or die "$_->{CommitId} ?";
456 return $classify->(qw(Pseudomerge),
457 SubType => qw(Ambiguous),
458 Overwritten => [ $bytime[0] ],
459 Contributor => $bytime[1]);
462 my ($p_h, $p_m) = get_commit $p->{CommitId};
463 $p->{IsOrigin} = $p_h !~ m/^parent \w+$/m;
464 ($p->{IsDgitImport},) = $p_m =~ m/^\[dgit import ([0-9a-z]+) .*\]$/m;
466 my @orig_ps = grep { ($_->{IsDgitImport}//'X') eq 'orig' } @p;
468 if (!(grep { !$_->{IsOrigin} } @p) and
469 (@orig_ps >= @p - 1) and
470 $m2 =~ s{^\[(dgit import unpatched .*)\]$}{[was: $1]}m) {
472 return $classify->(qw(DgitImportUnpatched),
473 OrigParents => \@orig_ps);
476 my ($stype, $series) = git_cat_file "$t:debian/patches/series";
477 my $haspatches = $stype ne 'missing' && $series =~ m/^\s*[^#\n\t ]/m;
479 # How to decide about l/r ordering of breakwater merges ? git
480 # --topo-order prefers to expand 2nd parent first. There's
481 # already an easy rune to look for debian/ history anyway (git log
482 # debian/) so debian breakwater branch should be 1st parent; that
483 # way also there's also an easy rune to look for the upstream
484 # patches (--topo-order).
486 # The above tells us which way *we* will generate them. But we
487 # might encounter ad-hoc breakwater merges generated manually,
488 # which might be the other way around. In principle, in some odd
489 # situations, a breakwater merge might have two identical parents.
490 # In that case we guess which way round it is (ie, which parent
491 # has the upstream history). The order of the 2-iteration loop
492 # controls which guess we make.
494 foreach my $prevbrw (qw(0 1)) {
497 !$p[$prevbrw]{IsOrigin} && # breakwater never starts with an origin
498 !($p[!$prevbrw]{Differs} & ~DS_DEB) && # no non-debian changess
499 !($p[$prevbrw]{Differs} & ~D_UPS)) { # no non-upstream changes
500 return $classify->(qw(BreakwaterUpstreamMerge),
501 OrigParents => [ $p[!$prevbrw] ]);
505 # multi-orig upstreams are represented with a breakwater merge
506 # from a single upstream commit which combines the orig tarballs
508 return $unknown->("complex merge");
514 $nogenerate,$report) = @_;
515 # => ($tip, $breakwater_tip, $last_upstream_merge_in_breakwater)
516 # (or nothing, if $nogenerate)
518 printdebug "*** WALK $input ".($nogenerate//0)." ".($report//'-')."\n";
520 # go through commits backwards
521 # we generate two lists of commits to apply:
522 # breakwater branch and upstream patches
523 my (@brw_cl, @upp_cl, @processed);
530 my ($prose, $info) = @_;
534 $ms .= "\n\n[git-debrebase$info: $prose]\n";
537 my $rewrite_from_here = sub {
538 my $sp_cl = { SpecialMethod => 'StartRewrite' };
539 push @brw_cl, $sp_cl;
540 push @processed, $sp_cl;
545 my $prprdelim = sub { print $report $prdelim if $report; $prdelim=""; };
548 return unless $report;
549 print $report $prdelim, @_;
553 my $bomb = sub { # usage: return $bomb->();
554 print $report " Unprocessable" if $report;
557 return (undef,undef);
559 die "commit $cur: Cannot cope with this commit (d.".
560 (join ' ', map { sprintf "%#x", $_->{Differs} }
561 @{ $cl->{Parents} }). ")";
567 my $build_start = sub {
568 my ($msg, $parent) = @_;
571 no warnings qw(exiting); last;
574 my $last_upstream_update;
578 my $ty = $cl->{Type};
579 my $st = $cl->{SubType};
580 $prline->("$cl->{CommitId} $cl->{Type}");
581 $found{$ty. ( defined($st) ? "-$st" : '' )}++;
582 push @processed, $cl;
583 my $p0 = @{ $cl->{Parents} }==1 ? $cl->{Parents}[0]{CommitId} : undef;
584 if ($ty eq 'AddPatches') {
586 $rewrite_from_here->();
588 } elsif ($ty eq 'Packaging' or $ty eq 'Changelog') {
592 } elsif ($ty eq 'BreakwaterStart') {
593 $last_upstream_update = $cur;
594 $build_start->('FirstPackaging', $cur);
595 } elsif ($ty eq 'Upstream') {
599 } elsif ($ty eq 'Mixed') {
602 my $cls = { %$cl, $xmsg->("split mixed commit: $wh part") };
605 $queue->(\@brw_cl, "debian");
606 $queue->(\@upp_cl, "upstream");
607 $rewrite_from_here->();
610 } elsif ($ty eq 'Pseudomerge') {
611 my $contrib = $cl->{Contributor}{CommitId};
612 print $report " Contributor=$contrib" if $report;
613 push @pseudomerges, $cl;
614 $rewrite_from_here->();
617 } elsif ($ty eq 'BreakwaterUpstreamMerge') {
618 $last_upstream_update = $cur;
619 $build_start->("PreviousBreakwater", $cur);
620 } elsif ($ty eq 'DgitImportUnpatched') {
621 my $pm = $pseudomerges[-1];
623 # To an extent, this is heuristic. Imports don't have
624 # a useful history of the debian/ branch. We assume
625 # that the first pseudomerge after an import has a
626 # useful history of debian/, and ignore the histories
627 # from later pseudomerges. Often the first pseudomerge
628 # will be the dgit import of the upload to the actual
629 # suite intended by the non-dgit NMUer, and later
630 # pseudomerges may represent in-archive copies.
631 my $ovwrs = $pm->{Overwritten};
632 printf $report " PM=%s \@Overwr:%d",
633 $pm->{CommitId}, (scalar @$ovwrs)
636 printdebug "*** WALK BOMB DgitImportUnpatched\n";
639 my $ovwr = $ovwrs->[0]{CommitId};
640 printf $report " Overwr=%s", $ovwr if $report;
641 # This import has a tree which is just like a
642 # breakwater tree, but it has the wrong history. It
643 # ought to have the previous breakwater (which the
644 # pseudomerge overwrote) as an ancestor. That will
645 # make the history of the debian/ files correct. As
646 # for the upstream version: either it's the same as
647 # was ovewritten (ie, same as the previous
648 # breakwater), in which case that history is precisely
649 # right; or, otherwise, it was a non-gitish upload of a
650 # new upstream version. We can tell these apart by
651 # looking at the tree of the supposed upstream.
654 SpecialMethod => 'DgitImportDebianUpdate',
655 $xmsg->("convert dgit import: debian changes")
658 SpecialMethod => 'DgitImportUpstreamUpdate',
659 $xmsg->("convert dgit import: upstream update",
662 $prline->(" Import");
663 $rewrite_from_here->();
664 $upp_limit //= $#upp_cl; # further, deeper, patches discarded
668 # Everything is from this import. This kind of import
669 # is already in valid breakwater format, with the
670 # patches as commits.
671 printf $report " NoPM" if $report;
672 # last thing we processed will have been the first patch,
673 # if there is one; which is fine, so no need to rewrite
674 # on account of this import
675 $build_start->("ImportOrigin", $cur);
679 printdebug "*** WALK BOMB unrecognised\n";
685 printdebug "*** WALK prep done cur=$cur".
686 " brw $#brw_cl upp $#upp_cl proc $#processed pm $#pseudomerges\n";
688 return if $nogenerate;
690 # Now we build it back up again
696 my $read_tree_debian = sub {
698 read_tree_subdir 'debian', "$treeish:debian";
699 rm_subdir_cached 'debian/patches';
701 my $read_tree_upstream = sub {
703 runcmd @git, qw(read-tree), $treeish;
704 $read_tree_debian->($build);
707 $#upp_cl = $upp_limit if defined $upp_limit;
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 } elsif ($method eq 'DgitImportUpstreamUpdate') {
744 confess unless $rewriting;
745 my $differs = (get_differs $build, $cltree);
746 next unless $differs & D_UPS;
747 $read_tree_upstream->($cltree);
748 push @parents, map { $_->{CommitId} } @{ $cl->{OrigParents} };
753 my $procd = (pop @processed) // 'UNDEF';
756 printdebug "WALK REWRITING NOW cl=$cl procd=$procd\n";
759 my $newtree = cmdoutput @git, qw(write-tree);
761 $ch =~ s{^tree .*}{tree $newtree}m or confess "$ch ?";
762 $ch =~ s{^parent .*\n}{}mg;
763 $ch =~ s{(?=^author)}{
764 join '', map { "parent $_\n" } @parents
765 }me or confess "$ch ?";
767 $ch =~ s{^committer .*$}{$committer_authline}m
770 my $cf = "$rd/m$rewriting";
771 open CD, ">", $cf or die $!;
772 print CD $ch, "\n", $cl->{Msg} or die $!;
774 my @cmd = (@git, qw(hash-object));
775 push @cmd, qw(-w) if $rewriting;
776 push @cmd, qw(-t commit), $cf;
777 my $newcommit = cmdoutput @cmd;
778 confess "$ch ?" unless $rewriting or $newcommit eq $cl->{CommitId};
780 if (grep { $method eq $_ } qw(DgitImportUpstreamUpdate)) {
781 $last_upstream_update = $cur;
786 my $final_check = get_differs $build, $input;
787 die sprintf "internal error %#x %s %s", $final_check, $build, $input
788 if $final_check & ~D_PAT_ADD;
790 my @r = ($build, $breakwater, $last_upstream_update);
791 printdebug "*** WALK RETURN @r\n";
796 git_check_unmodified();
797 return git_rev_parse qw(HEAD);
800 sub update_head ($$$) {
801 my ($old, $new, $mrest) = @_;
802 runcmd @git, qw(update-ref -m), "debrebase: $mrest", 'HEAD', $new, $old;
805 sub update_head_checkout ($$$) {
806 my ($old, $new, $mrest) = @_;
807 update_head $old, $new, $mrest;
808 runcmd @git, qw(reset --hard);
811 sub update_head_postlaunder ($$$) {
812 my ($old, $tip, $reflogmsg) = @_;
813 return if $tip eq $old;
814 print "git-debrebase: laundered (head was $old)\n";
815 update_head $old, $tip, $reflogmsg;
816 # no tree changes except debian/patches
817 runcmd @git, qw(rm --quiet --ignore-unmatch -rf debian/patches);
821 badusage "no arguments to launder allowed" if @ARGV;
822 my $old = get_head();
823 my ($tip,$breakwater,$last_upstream_merge) = walk $old;
824 update_head_postlaunder $old, $tip, 'launder';
825 printf "# breakwater tip\n%s\n", $breakwater;
826 printf "# working tip\n%s\n", $tip;
827 printf "# last upstream merge\n%s\n", $last_upstream_merge;
830 sub defaultcmd_rebase () {
831 my $old = get_head();
832 my ($status, $message) = record_ffq_prev();
833 if ($status eq 'written' || $status eq 'exists') {
835 fproblem $status, "could not record ffq-prev: $message";
836 fproblems_maybe_bail();
838 my ($tip,$breakwater) = walk $old;
839 update_head_postlaunder $old, $tip, 'launder for rebase';
840 runcmd @git, qw(rebase), @ARGV, $breakwater;
844 die if ($ARGV[0]//'') =~ m/^-/;
845 badusage "too many arguments to analyse" if @ARGV>1;
848 $old = git_rev_parse $old;
850 $old = git_rev_parse 'HEAD';
852 my ($dummy,$breakwater) = walk $old, 1,*STDOUT;
853 STDOUT->error and die $!;
856 sub ffq_prev_branchinfo () {
857 # => ('status', "message", [$current, $ffq_prev])
859 # branch message is undef
860 # weird-symref } no $current,
861 # notbranch } no $ffq_prev
862 my $current = git_get_symref();
863 return ('detached', 'detached HEAD') unless defined $current;
864 return ('weird-symref', 'HEAD symref is not to refs/')
865 unless $current =~ m{^refs/};
866 my $ffq_prev = "refs/$ffq_refprefix/$'";
867 return ('branch', undef, $current, $ffq_prev);
870 sub record_ffq_prev () {
871 # => ('status', "message")
873 # written message is undef
878 # if not ff from some branch we should be ff from, is an fproblem
879 # if "written", will have printed something about that to stdout,
880 # and also some messages about ff checks
881 my ($status, $message, $current, $ffq_prev) = ffq_prev_branchinfo();
882 return ($status, $message) unless $status eq 'branch';
884 my $currentval = get_head();
886 my $exists = git_get_ref $ffq_prev;
887 return ('exists',"$ffq_prev already exists") if $exists;
889 return ('not-branch', 'HEAD symref is not to refs/heads/')
890 unless $current =~ m{^refs/heads/};
893 my @check_specs = split /\;/, (cfg "branch.$branch.ffq-ffrefs",1) // '*';
897 my ($lrref, $desc) = @_;
899 for my $chk (@check_specs) {
901 $invert = $glob =~ s{^[^!]}{};
902 last if fnmatch $glob, $lrref;
905 my $lrval = git_get_ref $lrref;
906 return unless defined $lrval;
908 if (is_fast_fwd $lrval, $currentval) {
909 print "OK, you are ahead of $lrref\n" or die $!;
910 $checked{$lrref} = 1;
911 } if (is_fast_fwd $currentval, $lrval) {
912 $checked{$lrref} = -1;
913 fproblem 'behind', "you are behind $lrref, divergence risk";
915 $checked{$lrref} = -1;
916 fproblem 'diverged', "you have diverged from $lrref";
920 my $merge = cfg "branch.$branch.merge",1;
921 if (defined $merge && $merge =~ m{^refs/heads/}) {
923 my $check_remote = sub {
924 my ($remote, $desc) = (@_);
925 return unless defined $remote;
926 $check->("refs/remotes/$remote/$rhs", $desc);
928 $check_remote->((cfg "branch.$branch.remote",1),
929 'remote fetch/merge branch');
930 $check_remote->((cfg "branch.$branch.pushRemote",1) //
931 (cfg "branch.$branch.pushDefault",1),
932 'remote push branch');
934 if ($branch =~ m{^dgit/}) {
935 $check->("remotes/dgit/$branch", 'remote dgit branch');
936 } elsif ($branch =~ m{^master$}) {
937 $check->("remotes/dgit/dgit/sid", 'remote dgit branch for sid');
940 fproblems_maybe_bail();
941 runcmd @git, qw(update-ref -m), "record current head for preservation",
942 $ffq_prev, $currentval, $git_null_obj;
943 print "Recorded current head for preservation\n" or die $!;
944 return ('written', undef);
947 sub cmd_new_upstream_v0 () {
948 # automatically and unconditionally launders before rebasing
949 # if rebase --abort is used, laundering has still been done
953 badusage "need NEW-VERSION UPS-COMMITTISH" unless @ARGV >= 2;
955 # parse args - low commitment
956 my $new_version = (new Dpkg::Version scalar(shift @ARGV), check => 1);
957 my $new_upstream_version = $new_version->version();
959 my $new_upstream = git_rev_parse shift @ARGV;
962 my ($n, @x) = @_; # may be ''
963 my $pc = $pieces{$n} //= {
965 Desc => ($n ? "upstream piece \`$n'" : "upstream (main piece"),
967 while (my $k = shift @x) { $pc->{$k} = shift @x; }
973 my ($n, @x) = @_; # may be ''
974 my $pc = $piece->($n, @x, NewIx => (scalar @newpieces));
975 push @newpieces, $pc;
980 New => $new_upstream,
982 while (@ARGV && $ARGV[0] !~ m{^-}) {
985 badusage "for each EXTRA-UPS-NAME need EXTRA-UPS-COMMITISH"
986 unless @ARGV && $ARGV[0] !~ m{^-};
988 my $c = git_rev_parse shift @ARGV;
989 die unless $n =~ m/^$extra_orig_namepart_re$/;
990 $newpiece->($n, New => $c);
993 # now we need to investigate the branch this generates the
994 # laundered version but we don't switch to it yet
995 my $old_head = get_head();
996 my ($old_laundered_tip,$old_bw,$old_upstream_update) = walk $old_head;
998 my $old_bw_cl = classify $old_bw;
999 my $old_upstream_update_cl = classify $old_upstream_update;
1000 confess unless $old_upstream_update_cl->{OrigParents};
1001 my $old_upstream = parsecommit
1002 $old_upstream_update_cl->{OrigParents}[0]{CommitId};
1004 $piece->('', Old => $old_upstream->{CommitId});
1006 if ($old_upstream->{Msg} =~ m{^\[git-debrebase }m) {
1007 if ($old_upstream->{Msg} =~
1008 m{^\[git-debrebase upstream-combine \.((?: $extra_orig_namepart_re)+)\:.*\]$}m
1010 my @oldpieces = ('', split / /, $1);
1011 my $parentix = -1 + scalar @{ $old_upstream->{Parents} };
1012 foreach my $i (0..$#oldpieces) {
1013 my $n = $oldpieces[$i];
1014 $piece->($n, Old => $old_upstream->{CommitId}.'^'.$parentix);
1017 fproblem 'upstream-confusing',
1018 "previous upstream $old_upstream->{CommitId} is from".
1019 " git-debrebase but not an \`upstream-combine' commit";
1023 foreach my $pc (values %pieces) {
1025 fproblem 'upstream-new-piece',
1026 "introducing upstream piece \`$pc->{Name}'";
1027 } elsif (!$pc->{New}) {
1028 fproblem 'upstream-rm-piece',
1029 "dropping upstream piece \`$pc->{Name}'";
1030 } elsif (!is_fast_fwd $pc->{Old}, $pc->{New}) {
1031 fproblem 'upstream-not-ff',
1032 "not fast forward: $pc->{Name} $pc->{Old}..$pc->{New}";
1036 printdebug "%pieces = ", (dd \%pieces), "\n";
1037 printdebug "\@newpieces = ", (dd \@newpieces), "\n";
1039 fproblems_maybe_bail();
1045 my @upstream_merge_parents;
1047 if (!any_fproblems()) {
1048 push @upstream_merge_parents, $old_upstream->{CommitId};
1051 foreach my $pc (@newpieces) { # always has '' first
1053 read_tree_subdir $pc->{Name}, $pc->{New};
1055 runcmd @git, qw(read-tree), $pc->{New};
1057 push @upstream_merge_parents, $pc->{New};
1060 # index now contains the new upstream
1062 if (@newpieces > 1) {
1063 # need to make the upstream subtree merge commit
1064 $new_upstream = make_commit \@upstream_merge_parents,
1065 [ "Combine upstreams for $new_upstream_version",
1066 ("[git-debrebase upstream-combine . ".
1067 (join " ", map { $_->{Name} } @newpieces[1..$#newpieces]).
1072 # $new_upstream is either the single upstream commit, or the
1073 # combined commit we just made. Either way it will be the
1074 # "upstream" parent of the breakwater special merge.
1076 read_tree_subdir 'debian', "$old_bw:debian";
1078 # index now contains the breakwater merge contents
1079 $new_bw = make_commit [ $old_bw, $new_upstream ],
1080 [ "Update to upstream $new_upstream_version",
1081 "[git-debrebase breakwater: new upstream $new_upstream_version, merge]",
1084 # Now we have to add a changelog stanza so the Debian version
1086 die if unlink "debian";
1087 die $! unless $!==ENOENT or $!==ENOTEMPTY;
1088 unlink "debian/changelog" or $!==ENOENT or die $!;
1089 mkdir "debian" or die $!;
1090 open CN, ">", "debian/changelog" or die $!;
1091 my $oldclog = git_cat_file ":debian/changelog";
1092 $oldclog =~ m/^($package_re) \(\S+\) / or
1093 fail "cannot parse old changelog to get package name";
1095 print CN <<END, $oldclog or die $!;
1096 $p ($new_version) UNRELEASED; urgency=medium
1098 * Update to new upstream version $new_upstream_version.
1104 runcmd @git, qw(update-index --add --replace), 'debian/changelog';
1106 # Now we have the final new breakwater branch in the index
1107 $new_bw = make_commit [ $new_bw ],
1108 [ "Update changelog for new upstream $new_upstream_version",
1109 "[git-debrebase: new upstream $new_upstream_version, changelog]",
1113 # we have constructed the new breakwater. we now need to commit to
1114 # the laundering output, because git-rebase can't easily be made
1115 # to make a replay list which is based on some other branch
1117 update_head_postlaunder $old_head, $old_laundered_tip,
1118 'launder for new upstream';
1120 my @cmd = (@git, qw(rebase --onto), $new_bw, $old_bw, @ARGV);
1122 # now it's for the user to sort out
1125 sub cmd_record_ffq_prev () {
1126 badusage "no arguments allowed" if @ARGV;
1127 my ($status, $msg) = record_ffq_prev();
1128 if ($status eq 'exists' && $opt_noop_ok) {
1129 print "Previous head already recorded\n" or die $!;
1130 } elsif ($status eq 'written') {
1132 fail "Could not preserve: $msg";
1138 GetOptions('prose=s', \$prose) or die badusage("bad options to stitch");
1139 badusage "no arguments allowed" if @ARGV;
1140 my ($status, $message, $current, $ffq_prev) = ffq_prev_branchinfo();
1141 if ($status ne 'branch') {
1142 fproblem $status, "could not check ffq-prev: $message";
1143 fproblems_maybe_bail();
1145 my $prev = $ffq_prev && git_get_ref $ffq_prev;
1147 fail "No ffq-prev to stitch." unless $opt_noop_ok;
1150 my $old_head = get_head();
1151 my $new_head = make_commit [ $old_head, $ffq_prev ], [
1152 'Declare fast forward / record previous work',
1153 "[git-debrebase pseudomerge: stitch$prose]",
1155 my @upd_cmd = (@git, qw(update-ref --stdin));
1156 debugcmd '>|', @upd_cmd;
1157 open U, "|-", @upd_cmd or die $!;
1159 update HEAD $new_head $old_head
1160 delete $ffq_prev $prev
1162 printdebug ">= ", $_, "\n" foreach split /\n/, $u;
1165 close U or failedcmd @upd_cmd;
1168 sub cmd_convert_from_gbp () {
1169 badusage "needs 1 optional argument, the upstream git rev"
1171 my ($upstream_spec) = @ARGV;
1172 $upstream_spec //= 'refs/heads/upstream';
1173 my $upstream = git_rev_parse $upstream_spec;
1174 my $old_head = get_head();
1176 my $upsdiff = get_differs $upstream, $old_head;
1177 if ($upsdiff & D_UPS) {
1178 runcmd @git, qw(--no-pager diff),
1179 $upstream, $old_head,
1180 qw( -- :!/debian :/);
1181 fail "upstream ($upstream_spec) and HEAD are not identical in upstream files";
1184 if (!is_fast_fwd $upstream, $old_head) {
1185 fproblem 'upstream-not-ancestor',
1186 "upstream ($upstream) is not an ancestor of HEAD";
1188 my $wrong = cmdoutput
1189 (@git, qw(rev-list --ancestry-path), "$upstream..HEAD",
1190 qw(-- :/ :!/debian));
1191 if (length $wrong) {
1192 fproblem 'unexpected-upstream-changes',
1193 "history between upstream ($upstream) and HEAD contains direct changes to upstream files - are you sure this is a gbp (patches-unapplied) branch?";
1194 print STDERR "list expected changes with: git log --stat --ancestry-path $upstream_spec..HEAD -- :/ ':!/debian'\n";
1198 if ((git_cat_file "$upstream:debian")[0] ne 'missing') {
1199 fproblem 'upstream-has-debian',
1200 "upstream ($upstream) contains debian/ directory";
1203 fproblems_maybe_bail();
1209 runcmd @git, qw(checkout -q -b gdr-internal), $old_head;
1210 # make a branch out of the patch queue - we'll want this in a mo
1211 runcmd qw(gbp pq import);
1212 # strip the patches out
1213 runcmd @git, qw(checkout -q gdr-internal~0);
1214 rm_subdir_cached 'debian/patches';
1215 $work = make_commit ['HEAD'], [
1216 'git-debrebase convert-from-gbp: drop patches from tree',
1217 'Delete debian/patches, as part of converting to git-debrebase format.',
1218 '[git-debrebase convert-from-gbp: drop patches from tree]'
1220 # make the breakwater pseudomerge
1221 # the tree is already exactly right
1222 $work = make_commit [$work, $upstream], [
1223 'git-debrebase import: declare upstream',
1224 'First breakwater merge.',
1225 '[git-debrebase breakwater: declare upstream]'
1228 # rebase the patch queue onto the new breakwater
1229 runcmd @git, qw(reset --quiet --hard patch-queue/gdr-internal);
1230 runcmd @git, qw(rebase --quiet --onto), $work, qw(gdr-internal);
1231 $work = git_rev_parse 'HEAD';
1234 update_head_checkout $old_head, $work, 'convert-from-gbp';
1237 sub cmd_downstream_rebase_launder_v0 () {
1238 badusage "needs 1 argument, the baseline" unless @ARGV==1;
1240 $base = git_rev_parse $base;
1241 my $old_head = get_head();
1242 my $current = $old_head;
1245 if ($current eq $base) {
1246 $topmost_keep //= $current;
1247 print " $current BASE stop\n";
1250 my $cl = classify $current;
1251 print " $current $cl->{Type}";
1253 my $p0 = $cl->{Parents}[0]{CommitId};
1255 if ($cl->{Type} eq 'Pseudomerge') {
1256 print " ^".($cl->{Contributor}{Ix}+1);
1257 $next = $cl->{Contributor}{CommitId};
1258 } elsif ($cl->{Type} eq 'AddPatches' or
1259 $cl->{Type} eq 'Changelog') {
1269 $topmost_keep //= $current;
1271 die "to-be stripped changes not on top of the branch\n"
1276 if ($topmost_keep eq $old_head) {
1277 print "unchanged\n";
1279 print "updating to $topmost_keep\n";
1280 update_head_checkout
1281 $old_head, $topmost_keep,
1282 'downstream-rebase-launder-v0';
1286 GetOptions("D+" => \$debuglevel,
1287 'noop-ok', => \$opt_noop_ok,
1288 'f=s' => \@fproblem_force_opts,
1289 'force!') or die badusage "bad options\n";
1290 initdebug('git-debrebase ');
1291 enabledebug if $debuglevel;
1293 my $toplevel = cmdoutput @git, qw(rev-parse --show-toplevel);
1294 chdir $toplevel or die "chdir $toplevel: $!";
1296 $rd = fresh_playground "$playprefix/misc";
1298 if (!@ARGV || $ARGV[0] =~ m{^-}) {
1299 defaultcmd_rebase();
1301 my $cmd = shift @ARGV;
1304 $cmdfn = ${*::}{"cmd_$cmdfn"};
1306 $cmdfn or badusage "unknown git-debrebase sub-operation $cmd";