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>] breakwater # prints breakwater tip only
32 # git-debrebase [<options>] launder # prints breakwater tip etc.
33 # git-debrebase [<options>] stitch [--prose=<for commit message>]
34 # git-debrebase [<options>] downstream-rebase-launder-v0 # experimental
36 # git-debrebase [<options>] convert-from-gbp <upstream-git-rev>
38 # problems / outstanding questions:
40 # * dgit push with a `3.0 (quilt)' package means doing quilt
41 # fixup. Usually this involves recommitting the whole patch
42 # series, one at a time, with dpkg-source --commit. This is
43 # terribly terribly slow. (Maybe this should be fixed in dgit.)
45 # * dgit push usually needs to (re)make a pseudomerge. The "first"
46 # git-debrebase stripped out the previous pseudomerge and could
47 # have remembeed the HEAD. But it's not quite clear what history
48 # ought to be preserved and what should be discarded. For now
49 # the user will have to tell dgit --overwrite.
51 # To fix this, do we need a new push hook for dgit ?
53 # * Workflow is currently clumsy. Lots of spurious runes to type.
54 # There's not even a guide.
56 # * There are no tests.
58 # * new-upstream-v0 has a terrible UI. You end up with giant
59 # runic command lines.
61 # One consequence of the lack of richness it can need --force in
62 # fairly sensible situations and there is no way to tell it what
63 # you are really trying to do, other than just --force. There
64 # should be an interface with some default branch names.
66 # * There should be a standard convention for the version number,
67 # and unfinalised or not changelog, after new-upstream.
69 # * Handing of multi-orig dgit new-upstream .dsc imports is known to
70 # be broken. They may be not recognised, improperly converted, or
71 # their conversion may be unrecognised.
73 # * Docs need writing and updating. Even README.git-debrebase
74 # describes a design but may not reflect the implementation.
76 # * We need to develop a plausible model that works for derivatives,
77 # who probably want to maintain their stack on top of Debian's.
78 # downstream-rebase-launder-v0 may be a starting point?
82 use Debian::Dgit qw(:DEFAULT :playground);
89 use Getopt::Long qw(:config posix_default gnu_compat bundling);
91 use File::FnMatch qw(:fnmatch);
93 our ($opt_force, $opt_noop_ok);
95 our $us = qw(git-debrebase);
99 die "bad usage: $m\n";
103 my ($k, $optional) = @_;
105 my @cmd = qw(git config -z);
106 push @cmd, qw(--get-all) if wantarray;
108 my $out = cmdoutput_errok @cmd;
110 fail "missing required git config $k" unless $optional;
113 return split /\0/, $out;
120 my $dd = new Data::Dumper [ $v ];
121 Terse $dd 1; Indent $dd 0; Useqq $dd 1;
127 my $data = (git_cat_file $objid, 'commit');
128 $data =~ m/(?<=\n)\n/ or die "$objid ($data) ?";
132 sub D_UPS () { 0x02; } # upstream files
133 sub D_PAT_ADD () { 0x04; } # debian/patches/ extra patches at end
134 sub D_PAT_OTH () { 0x08; } # debian/patches other changes
135 sub D_DEB_CLOG () { 0x10; } # debian/ (not patches/ or changelog)
136 sub D_DEB_OTH () { 0x20; } # debian/changelog
137 sub DS_DEB () { D_DEB_CLOG | D_DEB_OTH; } # debian/ (not patches/)
139 our $playprefix = 'debrebase';
145 sub in_workarea ($) {
148 my $r = eval { $sub->(); };
149 { local $@; changedir $maindir; }
153 sub fresh_workarea () {
154 $workarea = fresh_playground "$playprefix/work";
155 in_workarea sub { playtree_setup };
158 sub get_differs ($$) {
160 # This resembles quiltify_trees_differ, in dgit, a bit.
161 # But we don't care about modes, or dpkg-source-unrepresentable
162 # changes, and we don't need the plethora of different modes.
163 # Conversely we need to distinguish different kinds of changes to
164 # debian/ and debian/patches/.
169 my ($opts, $limits, $fn) = @_;
170 my @cmd = (@git, qw(diff-tree -z --no-renames));
172 push @cmd, "$_:" foreach $x, $y;
173 push @cmd, '--', @$limits;
174 my $diffs = cmdoutput @cmd;
175 foreach (split /\0/, $diffs) { $fn->(); }
178 $rundiff->([qw(--name-only)], [], sub {
179 $differs |= $_ eq 'debian' ? DS_DEB : D_UPS;
182 if ($differs & DS_DEB) {
184 $rundiff->([qw(--name-only -r)], [qw(debian)], sub {
186 m{^debian/patches/} ? D_PAT_OTH :
187 $_ eq 'debian/changelog' ? D_DEB_CLOG :
190 die "mysterious debian changes $x..$y"
191 unless $differs & (D_PAT_OTH|DS_DEB);
194 if ($differs & D_PAT_OTH) {
196 $differs &= ~D_PAT_OTH;
198 $differs |= D_PAT_OTH;
199 no warnings qw(exiting); last;
201 $rundiff->([qw(--name-status -r)], [qw(debian/patches/)], sub {
202 no warnings qw(exiting);
203 if (!defined $mode) {
206 die unless s{^debian/patches/}{};
208 if ($mode eq 'A' && !m/\.series$/s) {
210 } elsif ($mode eq 'M' && $_ eq 'series') {
211 my $x_s = (git_cat_file "$x:debian/patches/series", 'blob');
212 my $y_s = (git_cat_file "$y:debian/patches/series", 'blob');
213 chomp $x_s; $x_s .= "\n";
214 $ok = $x_s eq substr($y_s, 0, length $x_s);
219 $differs |= $ok ? D_PAT_ADD : D_PAT_OTH;
221 die "mysterious debian/patches changes $x..$y"
222 unless $differs & (D_PAT_ADD|D_PAT_OTH);
225 printdebug sprintf "get_differs %s, %s = %#x\n", $x, $y, $differs;
230 sub commit_pr_info ($) {
232 return Data::Dumper->dump([$r], [qw(commit)]);
235 sub calculate_committer_authline () {
236 my $c = cmdoutput @git, qw(commit-tree --no-gpg-sign -m),
237 'DUMMY COMMIT (git-debrebase)', "HEAD:";
238 my ($h,$m) = get_commit $c;
239 $h =~ m/^committer .*$/m or confess "($h) ?";
243 sub rm_subdir_cached ($) {
245 runcmd @git, qw(rm --quiet -rf --cached --ignore-unmatch), $subdir;
248 sub read_tree_subdir ($$) {
249 my ($subdir, $new_tree_object) = @_;
250 rm_subdir_cached $subdir;
251 runcmd @git, qw(read-tree), "--prefix=$subdir/", $new_tree_object;
254 sub make_commit ($$) {
255 my ($parents, $message_paras) = @_;
256 my $tree = cmdoutput @git, qw(write-tree);
257 my @cmd = (@git, qw(commit-tree), $tree);
258 push @cmd, qw(-p), $_ foreach @$parents;
259 push @cmd, qw(-m), $_ foreach @$message_paras;
260 return cmdoutput @cmd;
263 our @fproblem_force_opts;
264 our $fproblems_forced;
265 our $fproblems_tripped;
268 if (grep { $_ eq $tag } @fproblem_force_opts) {
270 print STDERR "git-debrebase: safety catch overridden (-f$tag): $msg\n";
272 $fproblems_tripped++;
273 print STDERR "git-debrebase: safety catch tripped (-f$tag): $msg\n";
277 sub fproblems_maybe_bail () {
278 if ($fproblems_forced) {
280 "%s: safety catch trips: %d overriden by individual -f options\n",
281 $us, $fproblems_forced;
283 if ($fproblems_tripped) {
286 "%s: safety catch trips: %d overriden by global --force\n",
287 $us, $fproblems_tripped;
290 "%s: safety catch trips: %d blockers (you could -f<tag>, or --force)",
291 $us, $fproblems_tripped;
295 sub any_fproblems () {
296 return $fproblems_forced || $fproblems_tripped;
299 # classify returns an info hash like this
301 # Hdr => # commit headers, including 1 final newline
302 # Msg => # commit message (so one newline is dropped)
304 # Type => (see below)
306 # Ix => $index # ie 0, 1, 2, ...
308 # Differs => return value from get_differs
310 # IsDggitImport => 'orig' 'tarball' 'unpatched' 'package' (as from dgit)
312 # NewMsg => # commit message, but with any [dgit import ...] edited
313 # # to say "[was: ...]"
323 # has additional entres in classification result
324 # Overwritten = [ subset of Parents ]
325 # Contributor = $the_remaining_Parent
327 # DgitImportUnpatched
328 # has additional entry in classification result
329 # OrigParents = [ subset of Parents ]
331 # BreakwaterUpstreamMerge
332 # has additional entry in classification result
333 # OrigParents = [ subset of Parents ] # singleton list
336 # has additional entry in classification result
339 sub parsecommit ($;$) {
340 my ($objid, $p_ref) = @_;
341 # => hash with CommitId Hdr Msg Tree Parents
342 # Parents entries have only Ix CommitId
343 # $p_ref, if provided, must be [] and is used as a base for Parents
348 my ($h,$m) = get_commit $objid;
350 my ($t) = $h =~ m/^tree (\w+)$/m or die $objid;
351 my (@ph) = $h =~ m/^parent (\w+)$/mg;
361 foreach my $ph (@ph) {
363 Ix => scalar @$p_ref,
375 my $r = parsecommit($objid, \@p);
379 $p->{Differs} = (get_differs $p->{CommitId}, $t),
382 printdebug "classify $objid \$t=$t \@p",
383 (map { sprintf " %s/%#x", $_->{CommitId}, $_->{Differs} } @p),
387 my ($type, @rest) = @_;
388 $r = { %$r, Type => $type, @rest };
390 printdebug " = $type ".(dd $r)."\n";
396 $r = { %$r, Type => qw(Unknown), Why => $why };
397 printdebug " ** Unknown\n";
401 my $claims_to_be_breakwater =
402 $r->{Msg} =~ m{^\[git-debrebase breakwater.*\]$}m;
405 if ($claims_to_be_breakwater) {
406 return $unknown->("single-parent git-debrebase breakwater \`merge'");
408 my $d = $r->{Parents}[0]{Differs};
409 if ($d == D_PAT_ADD) {
410 return $classify->(qw(AddPatches));
411 } elsif ($d & (D_PAT_ADD|D_PAT_OTH)) {
412 return $unknown->("edits debian/patches");
413 } elsif ($d & DS_DEB and !($d & ~DS_DEB)) {
414 my ($ty,$dummy) = git_cat_file "$p[0]{CommitId}:debian";
416 if ($d == D_DEB_CLOG) {
417 return $classify->(qw(Changelog));
419 return $classify->(qw(Packaging));
421 } elsif ($ty eq 'missing') {
422 return $classify->(qw(BreakwaterStart));
424 return $unknown->("parent's debian is not a directory");
426 } elsif ($d == D_UPS) {
427 return $classify->(qw(Upstream));
428 } elsif ($d & DS_DEB and $d & D_UPS and !($d & ~(DS_DEB|D_UPS))) {
429 return $classify->(qw(Mixed));
431 return $unknown->("no changes");
433 confess "internal error $objid ?";
437 return $unknown->("origin commit");
440 my @identical = grep { !$_->{Differs} } @p;
441 if (@p == 2 && @identical == 1 && !$claims_to_be_breakwater
442 # breakwater merges can look like pseudomerges, if they are
443 # "declare" commits (ie, there are no upstream changes)
445 my @overwritten = grep { $_->{Differs} } @p;
446 confess "internal error $objid ?" unless @overwritten==1;
447 return $classify->(qw(Pseudomerge),
448 Overwritten => [ $overwritten[0] ],
449 Contributor => $identical[0]);
451 if (@p == 2 && @identical == 2) {
452 my @bytime = nsort_by {
453 my ($ph,$pm) = get_commit $_->{CommitId};
454 $ph =~ m/^committer .* (\d+) [-+]\d+$/m or die "$_->{CommitId} ?";
457 return $classify->(qw(Pseudomerge),
458 SubType => qw(Ambiguous),
459 Overwritten => [ $bytime[0] ],
460 Contributor => $bytime[1]);
463 my ($p_h, $p_m) = get_commit $p->{CommitId};
464 $p->{IsOrigin} = $p_h !~ m/^parent \w+$/m;
465 ($p->{IsDgitImport},) = $p_m =~ m/^\[dgit import ([0-9a-z]+) .*\]$/m;
467 my @orig_ps = grep { ($_->{IsDgitImport}//'X') eq 'orig' } @p;
469 if (!(grep { !$_->{IsOrigin} } @p) and
470 (@orig_ps >= @p - 1) and
471 $m2 =~ s{^\[(dgit import unpatched .*)\]$}{[was: $1]}m) {
473 return $classify->(qw(DgitImportUnpatched),
474 OrigParents => \@orig_ps);
477 my ($stype, $series) = git_cat_file "$t:debian/patches/series";
478 my $haspatches = $stype ne 'missing' && $series =~ m/^\s*[^#\n\t ]/m;
480 # How to decide about l/r ordering of breakwater merges ? git
481 # --topo-order prefers to expand 2nd parent first. There's
482 # already an easy rune to look for debian/ history anyway (git log
483 # debian/) so debian breakwater branch should be 1st parent; that
484 # way also there's also an easy rune to look for the upstream
485 # patches (--topo-order).
487 # The above tells us which way *we* will generate them. But we
488 # might encounter ad-hoc breakwater merges generated manually,
489 # which might be the other way around. In principle, in some odd
490 # situations, a breakwater merge might have two identical parents.
491 # In that case we guess which way round it is (ie, which parent
492 # has the upstream history). The order of the 2-iteration loop
493 # controls which guess we make.
495 foreach my $prevbrw (qw(0 1)) {
498 !$p[$prevbrw]{IsOrigin} && # breakwater never starts with an origin
499 !($p[!$prevbrw]{Differs} & ~DS_DEB) && # no non-debian changess
500 !($p[$prevbrw]{Differs} & ~D_UPS)) { # no non-upstream changes
501 return $classify->(qw(BreakwaterUpstreamMerge),
502 OrigParents => [ $p[!$prevbrw] ]);
506 # multi-orig upstreams are represented with a breakwater merge
507 # from a single upstream commit which combines the orig tarballs
509 return $unknown->("complex merge");
512 sub breakwater_of ($) {
513 my ($head) = @_; # must be laundered
517 fail "branch needs laundering (run git-debrebase): $why";
520 my $cl = classify $head;
521 my $ty = $cl->{Type};
522 if ($ty eq 'Packaging' or
523 $ty eq 'Changelog') {
524 $breakwater //= $head;
525 } elsif ($ty eq 'BreakwaterUpstreamMerge' or
526 $ty eq 'BreakwaterStart') {
527 $breakwater //= $head;
529 } elsif ($ty eq 'Upstream') {
530 $unclean->("packaging change ($breakwater)".
531 " follows upstream change (eg $head)")
532 if defined $breakwater;
533 } elsif ($ty eq 'Mixed') {
534 $unclean->('found mixed upstream/packaging commit ($head)');
535 } elsif ($ty eq 'Pseudomerge' or
536 $ty eq 'AddPatches') {
537 $unclean->("found interchange conversion commit ($ty, $head)");
538 } elsif ($ty eq 'DgitImportUnpatched') {
539 $unclean->("found dgit dsc import ($head)");
541 fail "found unprocessable commit, cannot cope: $head; $cl->{Why}";
543 $head = $cl->{Parents}[0]{CommitId};
551 $nogenerate,$report) = @_;
552 # => ($tip, $breakwater_tip, $last_upstream_merge_in_breakwater)
553 # (or nothing, if $nogenerate)
555 printdebug "*** WALK $input ".($nogenerate//0)." ".($report//'-')."\n";
557 # go through commits backwards
558 # we generate two lists of commits to apply:
559 # breakwater branch and upstream patches
560 my (@brw_cl, @upp_cl, @processed);
567 my ($prose, $info) = @_;
571 $ms .= "\n\n[git-debrebase$info: $prose]\n";
574 my $rewrite_from_here = sub {
575 my $sp_cl = { SpecialMethod => 'StartRewrite' };
576 push @brw_cl, $sp_cl;
577 push @processed, $sp_cl;
582 my $prprdelim = sub { print $report $prdelim if $report; $prdelim=""; };
585 return unless $report;
586 print $report $prdelim, @_;
590 my $bomb = sub { # usage: return $bomb->();
591 print $report " Unprocessable" if $report;
594 return (undef,undef);
596 die "commit $cur: Cannot cope with this commit (d.".
597 (join ' ', map { sprintf "%#x", $_->{Differs} }
598 @{ $cl->{Parents} }). ")";
604 my $build_start = sub {
605 my ($msg, $parent) = @_;
608 no warnings qw(exiting); last;
611 my $last_upstream_update;
615 my $ty = $cl->{Type};
616 my $st = $cl->{SubType};
617 $prline->("$cl->{CommitId} $cl->{Type}");
618 $found{$ty. ( defined($st) ? "-$st" : '' )}++;
619 push @processed, $cl;
620 my $p0 = @{ $cl->{Parents} }==1 ? $cl->{Parents}[0]{CommitId} : undef;
621 if ($ty eq 'AddPatches') {
623 $rewrite_from_here->();
625 } elsif ($ty eq 'Packaging' or $ty eq 'Changelog') {
629 } elsif ($ty eq 'BreakwaterStart') {
630 $last_upstream_update = $cur;
631 $build_start->('FirstPackaging', $cur);
632 } elsif ($ty eq 'Upstream') {
636 } elsif ($ty eq 'Mixed') {
639 my $cls = { %$cl, $xmsg->("split mixed commit: $wh part") };
642 $queue->(\@brw_cl, "debian");
643 $queue->(\@upp_cl, "upstream");
644 $rewrite_from_here->();
647 } elsif ($ty eq 'Pseudomerge') {
648 my $contrib = $cl->{Contributor}{CommitId};
649 print $report " Contributor=$contrib" if $report;
650 push @pseudomerges, $cl;
651 $rewrite_from_here->();
654 } elsif ($ty eq 'BreakwaterUpstreamMerge') {
655 $last_upstream_update = $cur;
656 $build_start->("PreviousBreakwater", $cur);
657 } elsif ($ty eq 'DgitImportUnpatched') {
658 my $pm = $pseudomerges[-1];
660 # To an extent, this is heuristic. Imports don't have
661 # a useful history of the debian/ branch. We assume
662 # that the first pseudomerge after an import has a
663 # useful history of debian/, and ignore the histories
664 # from later pseudomerges. Often the first pseudomerge
665 # will be the dgit import of the upload to the actual
666 # suite intended by the non-dgit NMUer, and later
667 # pseudomerges may represent in-archive copies.
668 my $ovwrs = $pm->{Overwritten};
669 printf $report " PM=%s \@Overwr:%d",
670 $pm->{CommitId}, (scalar @$ovwrs)
673 printdebug "*** WALK BOMB DgitImportUnpatched\n";
676 my $ovwr = $ovwrs->[0]{CommitId};
677 printf $report " Overwr=%s", $ovwr if $report;
678 # This import has a tree which is just like a
679 # breakwater tree, but it has the wrong history. It
680 # ought to have the previous breakwater (which the
681 # pseudomerge overwrote) as an ancestor. That will
682 # make the history of the debian/ files correct. As
683 # for the upstream version: either it's the same as
684 # was ovewritten (ie, same as the previous
685 # breakwater), in which case that history is precisely
686 # right; or, otherwise, it was a non-gitish upload of a
687 # new upstream version. We can tell these apart by
688 # looking at the tree of the supposed upstream.
691 SpecialMethod => 'DgitImportDebianUpdate',
692 $xmsg->("convert dgit import: debian changes")
695 SpecialMethod => 'DgitImportUpstreamUpdate',
696 $xmsg->("convert dgit import: upstream update",
699 $prline->(" Import");
700 $rewrite_from_here->();
701 $upp_limit //= $#upp_cl; # further, deeper, patches discarded
705 # Everything is from this import. This kind of import
706 # is already in valid breakwater format, with the
707 # patches as commits.
708 printf $report " NoPM" if $report;
709 # last thing we processed will have been the first patch,
710 # if there is one; which is fine, so no need to rewrite
711 # on account of this import
712 $build_start->("ImportOrigin", $cur);
716 printdebug "*** WALK BOMB unrecognised\n";
722 printdebug "*** WALK prep done cur=$cur".
723 " brw $#brw_cl upp $#upp_cl proc $#processed pm $#pseudomerges\n";
725 return if $nogenerate;
727 # Now we build it back up again
733 my $read_tree_debian = sub {
735 read_tree_subdir 'debian', "$treeish:debian";
736 rm_subdir_cached 'debian/patches';
738 my $read_tree_upstream = sub {
740 runcmd @git, qw(read-tree), $treeish;
741 $read_tree_debian->($build);
744 $#upp_cl = $upp_limit if defined $upp_limit;
746 my $committer_authline = calculate_committer_authline();
748 printdebug "WALK REBUILD $build ".(scalar @processed)."\n";
750 confess "internal error" unless $build eq (pop @processed)->{CommitId};
753 mkdir $rd or $!==EEXIST or die $!;
755 runcmd @git, qw(read-tree), $build;
756 foreach my $cl (qw(Debian), (reverse @brw_cl),
757 { SpecialMethod => 'RecordBreakwaterTip' },
758 qw(Upstream), (reverse @upp_cl)) {
760 $current_method = $cl;
763 my $method = $cl->{SpecialMethod} // $current_method;
764 my @parents = ($build);
765 my $cltree = $cl->{CommitId};
766 printdebug "WALK BUILD ".($cltree//'undef').
767 " $method (rewriting=$rewriting)\n";
768 if ($method eq 'Debian') {
769 $read_tree_debian->($cltree);
770 } elsif ($method eq 'Upstream') {
771 $read_tree_upstream->($cltree);
772 } elsif ($method eq 'StartRewrite') {
775 } elsif ($method eq 'RecordBreakwaterTip') {
776 $breakwater = $build;
778 } elsif ($method eq 'DgitImportDebianUpdate') {
779 $read_tree_debian->($cltree);
780 } elsif ($method eq 'DgitImportUpstreamUpdate') {
781 confess unless $rewriting;
782 my $differs = (get_differs $build, $cltree);
783 next unless $differs & D_UPS;
784 $read_tree_upstream->($cltree);
785 push @parents, map { $_->{CommitId} } @{ $cl->{OrigParents} };
790 my $procd = (pop @processed) // 'UNDEF';
793 printdebug "WALK REWRITING NOW cl=$cl procd=$procd\n";
796 my $newtree = cmdoutput @git, qw(write-tree);
798 $ch =~ s{^tree .*}{tree $newtree}m or confess "$ch ?";
799 $ch =~ s{^parent .*\n}{}mg;
800 $ch =~ s{(?=^author)}{
801 join '', map { "parent $_\n" } @parents
802 }me or confess "$ch ?";
804 $ch =~ s{^committer .*$}{$committer_authline}m
807 my $cf = "$rd/m$rewriting";
808 open CD, ">", $cf or die $!;
809 print CD $ch, "\n", $cl->{Msg} or die $!;
811 my @cmd = (@git, qw(hash-object));
812 push @cmd, qw(-w) if $rewriting;
813 push @cmd, qw(-t commit), $cf;
814 my $newcommit = cmdoutput @cmd;
815 confess "$ch ?" unless $rewriting or $newcommit eq $cl->{CommitId};
817 if (grep { $method eq $_ } qw(DgitImportUpstreamUpdate)) {
818 $last_upstream_update = $cur;
823 my $final_check = get_differs $build, $input;
824 die sprintf "internal error %#x %s %s", $final_check, $build, $input
825 if $final_check & ~D_PAT_ADD;
827 my @r = ($build, $breakwater, $last_upstream_update);
828 printdebug "*** WALK RETURN @r\n";
833 git_check_unmodified();
834 return git_rev_parse qw(HEAD);
837 sub update_head ($$$) {
838 my ($old, $new, $mrest) = @_;
839 runcmd @git, qw(update-ref -m), "debrebase: $mrest", 'HEAD', $new, $old;
842 sub update_head_checkout ($$$) {
843 my ($old, $new, $mrest) = @_;
844 update_head $old, $new, $mrest;
845 runcmd @git, qw(reset --hard);
848 sub update_head_postlaunder ($$$) {
849 my ($old, $tip, $reflogmsg) = @_;
850 return if $tip eq $old;
851 print "git-debrebase: laundered (head was $old)\n";
852 update_head $old, $tip, $reflogmsg;
853 # no tree changes except debian/patches
854 runcmd @git, qw(rm --quiet --ignore-unmatch -rf debian/patches);
858 badusage "no arguments to launder allowed" if @ARGV;
859 my $old = get_head();
860 my ($tip,$breakwater,$last_upstream_merge) = walk $old;
861 update_head_postlaunder $old, $tip, 'launder';
862 printf "# breakwater tip\n%s\n", $breakwater;
863 printf "# working tip\n%s\n", $tip;
864 printf "# last upstream merge\n%s\n", $last_upstream_merge;
867 sub defaultcmd_rebase () {
868 my $old = get_head();
869 my ($status, $message) = record_ffq_prev();
870 if ($status eq 'written' || $status eq 'exists') {
872 fproblem $status, "could not record ffq-prev: $message";
873 fproblems_maybe_bail();
875 my ($tip,$breakwater) = walk $old;
876 update_head_postlaunder $old, $tip, 'launder for rebase';
877 runcmd @git, qw(rebase), @ARGV, $breakwater;
881 die if ($ARGV[0]//'') =~ m/^-/;
882 badusage "too many arguments to analyse" if @ARGV>1;
885 $old = git_rev_parse $old;
887 $old = git_rev_parse 'HEAD';
889 my ($dummy,$breakwater) = walk $old, 1,*STDOUT;
890 STDOUT->error and die $!;
893 sub ffq_prev_branchinfo () {
894 # => ('status', "message", [$current, $ffq_prev])
896 # branch message is undef
897 # weird-symref } no $current,
898 # notbranch } no $ffq_prev
899 my $current = git_get_symref();
900 return ('detached', 'detached HEAD') unless defined $current;
901 return ('weird-symref', 'HEAD symref is not to refs/')
902 unless $current =~ m{^refs/};
903 my $ffq_prev = "refs/$ffq_refprefix/$'";
904 return ('branch', undef, $current, $ffq_prev);
907 sub record_ffq_prev () {
908 # => ('status', "message")
910 # written message is undef
915 # if not ff from some branch we should be ff from, is an fproblem
916 # if "written", will have printed something about that to stdout,
917 # and also some messages about ff checks
918 my ($status, $message, $current, $ffq_prev) = ffq_prev_branchinfo();
919 return ($status, $message) unless $status eq 'branch';
921 my $currentval = get_head();
923 my $exists = git_get_ref $ffq_prev;
924 return ('exists',"$ffq_prev already exists") if $exists;
926 return ('not-branch', 'HEAD symref is not to refs/heads/')
927 unless $current =~ m{^refs/heads/};
930 my @check_specs = split /\;/, (cfg "branch.$branch.ffq-ffrefs",1) // '*';
934 my ($lrref, $desc) = @_;
936 for my $chk (@check_specs) {
938 $invert = $glob =~ s{^[^!]}{};
939 last if fnmatch $glob, $lrref;
942 my $lrval = git_get_ref $lrref;
943 return unless defined $lrval;
945 if (is_fast_fwd $lrval, $currentval) {
946 print "OK, you are ahead of $lrref\n" or die $!;
947 $checked{$lrref} = 1;
948 } if (is_fast_fwd $currentval, $lrval) {
949 $checked{$lrref} = -1;
950 fproblem 'behind', "you are behind $lrref, divergence risk";
952 $checked{$lrref} = -1;
953 fproblem 'diverged', "you have diverged from $lrref";
957 my $merge = cfg "branch.$branch.merge",1;
958 if (defined $merge && $merge =~ m{^refs/heads/}) {
960 my $check_remote = sub {
961 my ($remote, $desc) = (@_);
962 return unless defined $remote;
963 $check->("refs/remotes/$remote/$rhs", $desc);
965 $check_remote->((cfg "branch.$branch.remote",1),
966 'remote fetch/merge branch');
967 $check_remote->((cfg "branch.$branch.pushRemote",1) //
968 (cfg "branch.$branch.pushDefault",1),
969 'remote push branch');
971 if ($branch =~ m{^dgit/}) {
972 $check->("remotes/dgit/$branch", 'remote dgit branch');
973 } elsif ($branch =~ m{^master$}) {
974 $check->("remotes/dgit/dgit/sid", 'remote dgit branch for sid');
977 fproblems_maybe_bail();
978 runcmd @git, qw(update-ref -m), "record current head for preservation",
979 $ffq_prev, $currentval, $git_null_obj;
980 print "Recorded current head for preservation\n" or die $!;
981 return ('written', undef);
984 sub cmd_new_upstream_v0 () {
985 # automatically and unconditionally launders before rebasing
986 # if rebase --abort is used, laundering has still been done
990 badusage "need NEW-VERSION UPS-COMMITTISH" unless @ARGV >= 2;
992 # parse args - low commitment
993 my $new_version = (new Dpkg::Version scalar(shift @ARGV), check => 1);
994 my $new_upstream_version = $new_version->version();
996 my $new_upstream = git_rev_parse shift @ARGV;
999 my ($n, @x) = @_; # may be ''
1000 my $pc = $pieces{$n} //= {
1002 Desc => ($n ? "upstream piece \`$n'" : "upstream (main piece"),
1004 while (my $k = shift @x) { $pc->{$k} = shift @x; }
1009 my $newpiece = sub {
1010 my ($n, @x) = @_; # may be ''
1011 my $pc = $piece->($n, @x, NewIx => (scalar @newpieces));
1012 push @newpieces, $pc;
1017 New => $new_upstream,
1019 while (@ARGV && $ARGV[0] !~ m{^-}) {
1020 my $n = shift @ARGV;
1022 badusage "for each EXTRA-UPS-NAME need EXTRA-UPS-COMMITISH"
1023 unless @ARGV && $ARGV[0] !~ m{^-};
1025 my $c = git_rev_parse shift @ARGV;
1026 die unless $n =~ m/^$extra_orig_namepart_re$/;
1027 $newpiece->($n, New => $c);
1030 # now we need to investigate the branch this generates the
1031 # laundered version but we don't switch to it yet
1032 my $old_head = get_head();
1033 my ($old_laundered_tip,$old_bw,$old_upstream_update) = walk $old_head;
1035 my $old_bw_cl = classify $old_bw;
1036 my $old_upstream_update_cl = classify $old_upstream_update;
1037 confess unless $old_upstream_update_cl->{OrigParents};
1038 my $old_upstream = parsecommit
1039 $old_upstream_update_cl->{OrigParents}[0]{CommitId};
1041 $piece->('', Old => $old_upstream->{CommitId});
1043 if ($old_upstream->{Msg} =~ m{^\[git-debrebase }m) {
1044 if ($old_upstream->{Msg} =~
1045 m{^\[git-debrebase upstream-combine \.((?: $extra_orig_namepart_re)+)\:.*\]$}m
1047 my @oldpieces = ('', split / /, $1);
1048 my $parentix = -1 + scalar @{ $old_upstream->{Parents} };
1049 foreach my $i (0..$#oldpieces) {
1050 my $n = $oldpieces[$i];
1051 $piece->($n, Old => $old_upstream->{CommitId}.'^'.$parentix);
1054 fproblem 'upstream-confusing',
1055 "previous upstream $old_upstream->{CommitId} is from".
1056 " git-debrebase but not an \`upstream-combine' commit";
1060 foreach my $pc (values %pieces) {
1062 fproblem 'upstream-new-piece',
1063 "introducing upstream piece \`$pc->{Name}'";
1064 } elsif (!$pc->{New}) {
1065 fproblem 'upstream-rm-piece',
1066 "dropping upstream piece \`$pc->{Name}'";
1067 } elsif (!is_fast_fwd $pc->{Old}, $pc->{New}) {
1068 fproblem 'upstream-not-ff',
1069 "not fast forward: $pc->{Name} $pc->{Old}..$pc->{New}";
1073 printdebug "%pieces = ", (dd \%pieces), "\n";
1074 printdebug "\@newpieces = ", (dd \@newpieces), "\n";
1076 fproblems_maybe_bail();
1082 my @upstream_merge_parents;
1084 if (!any_fproblems()) {
1085 push @upstream_merge_parents, $old_upstream->{CommitId};
1088 foreach my $pc (@newpieces) { # always has '' first
1090 read_tree_subdir $pc->{Name}, $pc->{New};
1092 runcmd @git, qw(read-tree), $pc->{New};
1094 push @upstream_merge_parents, $pc->{New};
1097 # index now contains the new upstream
1099 if (@newpieces > 1) {
1100 # need to make the upstream subtree merge commit
1101 $new_upstream = make_commit \@upstream_merge_parents,
1102 [ "Combine upstreams for $new_upstream_version",
1103 ("[git-debrebase upstream-combine . ".
1104 (join " ", map { $_->{Name} } @newpieces[1..$#newpieces]).
1109 # $new_upstream is either the single upstream commit, or the
1110 # combined commit we just made. Either way it will be the
1111 # "upstream" parent of the breakwater special merge.
1113 read_tree_subdir 'debian', "$old_bw:debian";
1115 # index now contains the breakwater merge contents
1116 $new_bw = make_commit [ $old_bw, $new_upstream ],
1117 [ "Update to upstream $new_upstream_version",
1118 "[git-debrebase breakwater: new upstream $new_upstream_version, merge]",
1121 # Now we have to add a changelog stanza so the Debian version
1123 die if unlink "debian";
1124 die $! unless $!==ENOENT or $!==ENOTEMPTY;
1125 unlink "debian/changelog" or $!==ENOENT or die $!;
1126 mkdir "debian" or die $!;
1127 open CN, ">", "debian/changelog" or die $!;
1128 my $oldclog = git_cat_file ":debian/changelog";
1129 $oldclog =~ m/^($package_re) \(\S+\) / or
1130 fail "cannot parse old changelog to get package name";
1132 print CN <<END, $oldclog or die $!;
1133 $p ($new_version) UNRELEASED; urgency=medium
1135 * Update to new upstream version $new_upstream_version.
1141 runcmd @git, qw(update-index --add --replace), 'debian/changelog';
1143 # Now we have the final new breakwater branch in the index
1144 $new_bw = make_commit [ $new_bw ],
1145 [ "Update changelog for new upstream $new_upstream_version",
1146 "[git-debrebase: new upstream $new_upstream_version, changelog]",
1150 # we have constructed the new breakwater. we now need to commit to
1151 # the laundering output, because git-rebase can't easily be made
1152 # to make a replay list which is based on some other branch
1154 update_head_postlaunder $old_head, $old_laundered_tip,
1155 'launder for new upstream';
1157 my @cmd = (@git, qw(rebase --onto), $new_bw, $old_bw, @ARGV);
1159 # now it's for the user to sort out
1162 sub cmd_record_ffq_prev () {
1163 badusage "no arguments allowed" if @ARGV;
1164 my ($status, $msg) = record_ffq_prev();
1165 if ($status eq 'exists' && $opt_noop_ok) {
1166 print "Previous head already recorded\n" or die $!;
1167 } elsif ($status eq 'written') {
1169 fail "Could not preserve: $msg";
1173 sub cmd_breakwater () {
1174 badusage "no arguments allowed" if @ARGV;
1175 my $bw = breakwater_of git_rev_parse 'HEAD';
1176 print "$bw\n" or die $!;
1181 GetOptions('prose=s', \$prose) or die badusage("bad options to stitch");
1182 badusage "no arguments allowed" if @ARGV;
1183 my ($status, $message, $current, $ffq_prev) = ffq_prev_branchinfo();
1184 if ($status ne 'branch') {
1185 fproblem $status, "could not check ffq-prev: $message";
1186 fproblems_maybe_bail();
1188 my $prev = $ffq_prev && git_get_ref $ffq_prev;
1190 fail "No ffq-prev to stitch." unless $opt_noop_ok;
1193 my $old_head = get_head();
1194 my $new_head = make_commit [ $old_head, $ffq_prev ], [
1195 'Declare fast forward / record previous work',
1196 "[git-debrebase pseudomerge: stitch$prose]",
1198 my @upd_cmd = (@git, qw(update-ref --stdin));
1199 debugcmd '>|', @upd_cmd;
1200 open U, "|-", @upd_cmd or die $!;
1202 update HEAD $new_head $old_head
1203 delete $ffq_prev $prev
1205 printdebug ">= ", $_, "\n" foreach split /\n/, $u;
1208 close U or failedcmd @upd_cmd;
1211 sub cmd_convert_from_gbp () {
1212 badusage "needs 1 optional argument, the upstream git rev"
1214 my ($upstream_spec) = @ARGV;
1215 $upstream_spec //= 'refs/heads/upstream';
1216 my $upstream = git_rev_parse $upstream_spec;
1217 my $old_head = get_head();
1219 my $upsdiff = get_differs $upstream, $old_head;
1220 if ($upsdiff & D_UPS) {
1221 runcmd @git, qw(--no-pager diff),
1222 $upstream, $old_head,
1223 qw( -- :!/debian :/);
1224 fail "upstream ($upstream_spec) and HEAD are not identical in upstream files";
1227 if (!is_fast_fwd $upstream, $old_head) {
1228 fproblem 'upstream-not-ancestor',
1229 "upstream ($upstream) is not an ancestor of HEAD";
1231 my $wrong = cmdoutput
1232 (@git, qw(rev-list --ancestry-path), "$upstream..HEAD",
1233 qw(-- :/ :!/debian));
1234 if (length $wrong) {
1235 fproblem 'unexpected-upstream-changes',
1236 "history between upstream ($upstream) and HEAD contains direct changes to upstream files - are you sure this is a gbp (patches-unapplied) branch?";
1237 print STDERR "list expected changes with: git log --stat --ancestry-path $upstream_spec..HEAD -- :/ ':!/debian'\n";
1241 if ((git_cat_file "$upstream:debian")[0] ne 'missing') {
1242 fproblem 'upstream-has-debian',
1243 "upstream ($upstream) contains debian/ directory";
1246 fproblems_maybe_bail();
1252 runcmd @git, qw(checkout -q -b gdr-internal), $old_head;
1253 # make a branch out of the patch queue - we'll want this in a mo
1254 runcmd qw(gbp pq import);
1255 # strip the patches out
1256 runcmd @git, qw(checkout -q gdr-internal~0);
1257 rm_subdir_cached 'debian/patches';
1258 $work = make_commit ['HEAD'], [
1259 'git-debrebase convert-from-gbp: drop patches from tree',
1260 'Delete debian/patches, as part of converting to git-debrebase format.',
1261 '[git-debrebase convert-from-gbp: drop patches from tree]'
1263 # make the breakwater pseudomerge
1264 # the tree is already exactly right
1265 $work = make_commit [$work, $upstream], [
1266 'git-debrebase import: declare upstream',
1267 'First breakwater merge.',
1268 '[git-debrebase breakwater: declare upstream]'
1271 # rebase the patch queue onto the new breakwater
1272 runcmd @git, qw(reset --quiet --hard patch-queue/gdr-internal);
1273 runcmd @git, qw(rebase --quiet --onto), $work, qw(gdr-internal);
1274 $work = git_rev_parse 'HEAD';
1277 update_head_checkout $old_head, $work, 'convert-from-gbp';
1280 sub cmd_downstream_rebase_launder_v0 () {
1281 badusage "needs 1 argument, the baseline" unless @ARGV==1;
1283 $base = git_rev_parse $base;
1284 my $old_head = get_head();
1285 my $current = $old_head;
1288 if ($current eq $base) {
1289 $topmost_keep //= $current;
1290 print " $current BASE stop\n";
1293 my $cl = classify $current;
1294 print " $current $cl->{Type}";
1296 my $p0 = $cl->{Parents}[0]{CommitId};
1298 if ($cl->{Type} eq 'Pseudomerge') {
1299 print " ^".($cl->{Contributor}{Ix}+1);
1300 $next = $cl->{Contributor}{CommitId};
1301 } elsif ($cl->{Type} eq 'AddPatches' or
1302 $cl->{Type} eq 'Changelog') {
1312 $topmost_keep //= $current;
1314 die "to-be stripped changes not on top of the branch\n"
1319 if ($topmost_keep eq $old_head) {
1320 print "unchanged\n";
1322 print "updating to $topmost_keep\n";
1323 update_head_checkout
1324 $old_head, $topmost_keep,
1325 'downstream-rebase-launder-v0';
1329 GetOptions("D+" => \$debuglevel,
1330 'noop-ok', => \$opt_noop_ok,
1331 'f=s' => \@fproblem_force_opts,
1332 'force!') or die badusage "bad options\n";
1333 initdebug('git-debrebase ');
1334 enabledebug if $debuglevel;
1336 my $toplevel = cmdoutput @git, qw(rev-parse --show-toplevel);
1337 chdir $toplevel or die "chdir $toplevel: $!";
1339 $rd = fresh_playground "$playprefix/misc";
1341 if (!@ARGV || $ARGV[0] =~ m{^-}) {
1342 defaultcmd_rebase();
1344 my $cmd = shift @ARGV;
1347 $cmdfn = ${*::}{"cmd_$cmdfn"};
1349 $cmdfn or badusage "unknown git-debrebase sub-operation $cmd";