# You should have received a copy of the GNU General Public License
# along with this program. If not, see <http://www.gnu.org/licenses/>.
+# git-debrebase new-upstreams-v0 \
+# NEW-VERSION ORIG-COMMITISH
+# [EXTRA-ORIG-NAME EXTRA-ORIG-COMMITISH ...]
+
# usages:
# git-debrebase status
# git-debrebase start # like ffqrebase start + debrebase launder
use strict;
+use Debian::Dgit qw(:DEFAULT :playground);
+setup_sigwarn();
+
use Memoize;
use Carp;
+use POSIX;
use Data::Dumper;
+use Getopt::Long qw(:config posix_default gnu_compat bundling);
+use Dpkg::Version;
-use Debian::Dgit qw(:DEFAULT $wa);
+our ($opt_force);
sub badusage ($) {
my ($m) = @_;
sub get_commit ($) {
my ($objid) = @_;
- my ($type,$data) = git_cat_file $objid;
- die unless $type eq 'commit';
- $data =~ m/(?<=\n)\n/;
+ my $data = git_cat_file $objid, 'commit';
+ $data =~ m/(?<=\n)\n/ or die "$objid ($data) ?";
return ($`,$');
}
-sub D_DEB () { return 0x1; } # debian/ (not including debian/patches/)
-sub D_UPS () { return 0x2; } # upstream files
-sub D_PAT_ADD () { return 0x4; } # debian/patches/ extra patches at end
-sub D_PAT_OTH () { return 0x8; } # debian/patches other changes
+sub D_UPS () { 0x02; } # upstream files
+sub D_PAT_ADD () { 0x04; } # debian/patches/ extra patches at end
+sub D_PAT_OTH () { 0x08; } # debian/patches other changes
+sub D_DEB_CLOG () { 0x10; } # debian/ (not patches/ or changelog)
+sub D_DEB_OTH () { 0x20; } # debian/changelog
+sub DS_DEB () { D_DEB_CLOG | D_DEB_OTH; } # debian/ (not patches/)
+
+our $playprefix = 'debrebase';
+our $rd;
+our $workarea;
-our $rd = ".git/git-debrebase";
-our $ud = "$rd/work";
our @git = qw(git);
+sub in_workarea ($) {
+ my ($sub) = @_;
+ changedir $workarea;
+ my $r = eval { $sub->(); };
+ { local $@; changedir $maindir; }
+ die $@ if $@;
+}
+
+sub fresh_workarea () {
+ $workarea = fresh_playground "$playprefix/work";
+ in_workarea sub { playtree_setup };
+}
+
+sub get_differs ($$) {
+ my ($x,$y) = @_;
+ # This resembles quiltify_trees_differ, in dgit, a bit.
+ # But we don't care about modes, or dpkg-source-unrepresentable
+ # changes, and we don't need the plethora of different modes.
+ # Conversely we need to distinguish different kinds of changes to
+ # debian/ and debian/patches/.
+
+ my $differs = 0;
+
+ my $rundiff = sub {
+ my ($opts, $limits, $fn) = @_;
+ my @cmd = (@git, qw(diff-tree -z --no-renames));
+ push @cmd, @$opts;
+ push @cmd, "$_:" foreach $x, $y;
+ push @cmd, @$limits;
+ my $diffs = cmdoutput @cmd;
+ foreach (split /\0/, $diffs) { $fn->(); }
+ };
+
+ $rundiff->([qw(--name-only)], [], sub {
+ $differs |= $_ eq 'debian' ? DS_DEB : D_UPS;
+ });
+
+ if ($differs & DS_DEB) {
+ $differs &= ~DS_DEB;
+ $rundiff->([qw(--name-only -r)], [qw(debian)], sub {
+ $differs |=
+ m{^debian/patches/} ? D_PAT_OTH :
+ $_ eq 'debian/changelog' ? D_DEB_CLOG :
+ D_DEB_OTH;
+ });
+ die "mysterious debian changes $x..$y"
+ unless $differs & (D_PAT_OTH|DS_DEB);
+ }
+
+ if ($differs & D_PAT_OTH) {
+ my $mode;
+ $differs &= ~D_PAT_OTH;
+ my $pat_oth = sub {
+ $differs |= D_PAT_OTH;
+ no warnings qw(exiting); last;
+ };
+ $rundiff->([qw(--name-status -r)], [qw(debian/patches/)], sub {
+ no warnings qw(exiting);
+ if (!defined $mode) {
+ $mode = $_; next;
+ }
+ die unless s{^debian/patches/}{};
+ my $ok;
+ if ($mode eq 'A' && !m/\.series$/s) {
+ $ok = 1;
+ } elsif ($mode eq 'M' && $_ eq 'series') {
+ my $x_s = git_cat_file "$x:debian/patches/series", 'blob';
+ my $y_s = git_cat_file "$y:debian/patches/series", 'blob';
+ chomp $x_s; $x_s .= "\n";
+ $ok = $x_s eq substr($y_s, 0, length $x_s);
+ } else {
+ # nope
+ }
+ $mode = undef;
+ $differs |= $ok ? D_PAT_ADD : D_PAT_OTH;
+ });
+ die "mysterious debian/patches changes $x..$y"
+ unless $differs & (D_PAT_ADD|D_PAT_OTH);
+ }
+
+ printdebug sprintf "get_differs %s, %s = %#x\n", $x, $y, $differs;
+
+ return $differs;
+}
+
sub commit_pr_info ($) {
my ($r) = @_;
return Data::Dumper->dump([$r], [qw(commit)]);
return $&;
}
+sub rm_subdir_cached ($) {
+ my ($subdir) = @_;
+ runcmd @git, qw(rm --quiet -rf --cached --ignore-unmatch), $subdir;
+}
+
+sub read_tree_subdir ($$) {
+ my ($subdir, $new_tree_object) = @_;
+ rm_subdir_cached $subdir;
+ runcmd @git, qw(read-tree), "--prefix=$subdir/", $new_tree_object;
+}
+
# classify returns an info hash like this
# CommitId => $objid
# Hdr => # commit headers, including 1 final newline
#
# Types:
# Packaging
+# Changelog
# Upstream
# AddPatches
# Mixed
#
# BreakwaterUpstreamMerge
# has additional entry in classification result
-# OrigParents = [ subset of Parents ]
+# OrigParents = [ subset of Parents ] # singleton list
-sub classify ($) {
- my ($objid) = @_;
+sub parsecommit ($;$) {
+ my ($objid, $p_ref) = @_;
+ # => hash with CommitId Hdr Msg Tree Parents
+ # Parents entries have only Ix CommitId
+ # $p_ref, if provided, must be [] and is used as a base for Parents
+
+ $p_ref //= [];
+ die if @$p_ref;
my ($h,$m) = get_commit $objid;
my ($t) = $h =~ m/^tree (\w+)$/m or die $objid;
- my (@ph) = $h =~ m/^parent (\w+)$/m;
- my @p;
+ my (@ph) = $h =~ m/^parent (\w+)$/mg;
my $r = {
CommitId => $objid,
Hdr => $h,
Msg => $m,
Tree => $t,
- Parents => \@p,
+ Parents => $p_ref,
};
foreach my $ph (@ph) {
- push @p, {
- Ix => $#p,
+ push @$p_ref, {
+ Ix => $#$p_ref,
CommitId => $ph,
- Differs => (get_differs $t, $ph),
};
}
+ return $r;
+}
+
+sub classify ($) {
+ my ($objid) = @_;
+
+ my @p;
+ my $r = parsecommit($objid, \@p);
+ my $t = $r->{Tree};
+
+ foreach my $p (@p) {
+ $p->{Differs} = (get_differs $p->{CommitId}, $t),
+ }
+
+ printdebug "classify $objid \$t=$t \@p",
+ (map { sprintf " %s/%#x", $_->{CommitId}, $_->{Differs} } @p),
+ "\n";
+
my $classify = sub {
my ($type, @rest) = @_;
$r = { %$r, Type => $type, @rest };
+ if ($debuglevel) {
+ my $dd = new Data::Dumper [ $r ];
+ Terse $dd 1; Indent $dd 0; Useqq $dd 1;
+ printdebug " = $type ".(Dump $dd)."\n";
+ }
return $r;
};
my $unknown = sub {
my ($why) = @_;
$r = { %$r, Type => qw(Unknown) };
+ printdebug " ** Unknown\n";
return $r;
};
return $classify->(qw(AddPatches));
} elsif ($d & (D_PAT_ADD|D_PAT_OTH)) {
return $unknown->("edits debian/patches");
- } elsif ($d == D_DEB) {
- my ($ty,$dummy) = git_cat_file "$ph[0]:debian";
+ } elsif ($d & DS_DEB and !($d & ~DS_DEB)) {
+ my ($ty,$dummy) = git_cat_file "$p[0]{CommitId}:debian";
if ($ty eq 'tree') {
- return $classify->(qw(Packaging));
+ if ($d == D_DEB_CLOG) {
+ return $classify->(qw(Changelog));
+ } else {
+ return $classify->(qw(Packaging));
+ }
} elsif ($ty eq 'missing') {
return $classify->(qw(BreakwaterStart));
} else {
}
} elsif ($d == D_UPS) {
return $classify->(qw(Upstream));
- } elsif ($d == (D_DEB|D_UPS)) {
+ } elsif ($d & DS_DEB and $d & D_UPS and !($d & ~(DS_DEB|D_UPS))) {
return $classify->(qw(Mixed));
} elsif ($d == 0) {
return $unknown->("no changes");
Contributor => $bytime[1]);
}
foreach my $p (@p) {
- my ($p_h, $p_m) = get_commit $p;
+ my ($p_h, $p_m) = get_commit $p->{CommitId};
$p->{IsOrigin} = $p_h !~ m/^parent \w+$/m;
($p->{IsDgitImport},) = $p_m =~ m/^\[dgit import ([0-9a-z]+) .*\]$/m;
}
my @orig_ps = grep { ($_->{IsDgitImport}//'X') eq 'orig' } @p;
- my $m2 = $m;
+ my $m2 = $r->{Msg};
if (!(grep { !$_->{IsOrigin} } @p) and
(@orig_ps >= @p - 1) and
$m2 =~ s{^\[(dgit import unpatched .*)\]$}{[was: $1]}m) {
# debian/) so debian breakwater branch should be 1st parent; that
# way also there's also an easy rune to look for the upstream
# patches (--topo-order).
- if (@p == 2 &&
- !$haspatches &&
- !$p[0]{IsOrigin} && # breakwater merge never starts with an origin
- !($p[0]{Differs} & ~D_DEB) &&
- !($p[1]{Differs} & ~D_UPS)) {
- return $classify->(qw(BreakwaterUpstreamMerge),
- OrigParents => [ $p[1] ]);
+
+ # The above tells us which way *we* will generate them. But we
+ # might encounter ad-hoc breakwater merges generated manually,
+ # which might be the other way around. In principle, in some odd
+ # situations, a breakwater merge might have two identical parents.
+ # In that case we guess which way round it is (ie, which parent
+ # has the upstream history). The order of the 2-iteration loop
+ # controls which guess we make.
+
+ foreach my $prevbrw (qw(0 1)) {
+ if (@p == 2 &&
+ !$haspatches &&
+ !$p[$prevbrw]{IsOrigin} && # breakwater never starts with an origin
+ !($p[$prevbrw]{Differs} & ~DS_DEB) &&
+ !($p[!$prevbrw]{Differs} & ~D_UPS)) {
+ return $classify->(qw(BreakwaterUpstreamMerge),
+ OrigParents => [ $p[!$prevbrw] ]);
+ }
}
- # xxx multi-.orig upstreams
+
+ # multi-orig upstreams are represented with a breakwater merge
+ # from a single upstream commit which combines the orig tarballs
return $unknown->("complex merge");
}
-sub walk ($;$$$$);
-sub walk {
+sub walk ($;$$);
+sub walk ($;$$) {
my ($input,
- $nogenerate,$report,
- $wantdebonly,$depth) = @_;
- # => ($tip, $breakwater_tip)
+ $nogenerate,$report) = @_;
+ # => ($tip, $breakwater_tip, $last_upstream_merge_in_breakwater)
+ # (or nothing, if $nogenerate)
# go through commits backwards
- # we generate two lists of commits to apply
- my (@deb_cl, @ups_cl, @processed);
+ # we generate two lists of commits to apply:
+ # breakwater branch and upstream patches
+ my (@brw_cl, @upp_cl, @processed);
my %found;
+ my $upp_limit;
my @pseudomerges;
- $depth //= 0;
-
my $cl;
my $xmsg = sub {
my ($appendinfo) = @_;
return (Msg => $ms);
};
my $rewrite_from_here = sub {
- push @processed, { SpecialMethod => 'StartRewrite' };
+ my $sp_cl = { SpecialMethod => 'StartRewrite' };
+ push @brw_cl, $sp_cl;
+ push @processed, $sp_cl;
};
-
my $cur = $input;
my $prdelim = "";
if ($nogenerate) {
return (undef,undef);
}
- die "commit $cur: Cannot cope with this commit";
+ die "commit $cur: Cannot cope with this commit (d.".
+ (join ' ', map { sprintf "%#x", $_->{Differs} }
+ @{ $cl->{Parents} }). ")";
};
+ my $build;
+ my $breakwater;
+
+ my $build_start = sub {
+ my ($msg, $parent) = @_;
+ $prline->(" $msg");
+ $build = $parent;
+ no warnings qw(exiting); last;
+ };
+
+ my $last_upstream_update;
+
for (;;) {
- if (!defined $cur) {
- push @deb_cl, { ExactlyParents => [] };
- $prline->("Origin");
- last;
- }
$cl = classify $cur;
my $ty = $cl->{Type};
my $st = $cl->{SubType};
$cur = $p0;
$rewrite_from_here->();
next;
- } elsif ($ty eq 'Packaging') {
- push @deb_cl, $cl;
- $cur = $p0;
- next;
- } elsif ($ty eq 'Packaging') {
- push @deb_cl, $cl;
+ } elsif ($ty eq 'Packaging' or $ty eq 'Changelog') {
+ push @brw_cl, $cl;
$cur = $p0;
next;
+ } elsif ($ty eq 'BreakwaterStart') {
+ $last_upstream_update = $cur;
+ $build_start->('FirstPackaging', $cur);
} elsif ($ty eq 'Upstream') {
- push @ups_cl, $cl;
+ push @upp_cl, $cl;
$cur = $p0;
next;
} elsif ($ty eq 'Mixed') {
my $queue = sub {
my ($q, $wh) = @_;
- my $cls = { $cl, $xmsg->("split mixed commit: $wh part") };
+ my $cls = { %$cl, $xmsg->("split mixed commit: $wh part") };
push @$q, $cls;
};
- $queue->(\@deb_cl, "debian");
- $queue->(\@ups_cl, "upstream");
+ $queue->(\@brw_cl, "debian");
+ $queue->(\@upp_cl, "upstream");
$rewrite_from_here->();
+ $cur = $p0;
next;
} elsif ($ty eq 'Pseudomerge') {
- print $report " Contributor=$ty->{Contributor}" if $report;
+ my $contrib = $cl->{Contributor}{CommitId};
+ print $report " Contributor=$contrib" if $report;
push @pseudomerges, $cl;
$rewrite_from_here->();
- $cur = $ty->{Contributor};
+ $cur = $contrib;
next;
} elsif ($ty eq 'BreakwaterUpstreamMerge') {
- push @deb_cl, { ExactlyParents => [$cur] };
- $prline->("PreviousBreakwater");
- last;
+ $last_upstream_update = $cur;
+ $build_start->("PreviousBreakwater", $cur);
} elsif ($ty eq 'DgitImportUnpatched') {
my $pm = $pseudomerges[-1];
if (defined $pm) {
# right; or, otherwise, it was a non-gitish upload of a
# new upstream version. We can tell these apart by
# looking at the tree of the supposed upstream.
- push @deb_cl, {
+ push @brw_cl, {
%$cl,
SpecialMethod => 'DgitImportDebianUpdate',
$xmsg->("convert dgit import: debian changes")
# deleted .gitignore (which is a thing that some of
# the existing git tools do if the user doesn't
# somehow tell them not to). Ah well.
- push @deb_cl, {
+ push @brw_cl, {
%$cl,
SpecialMethod => 'DgitImportUpstreamUpdate',
$xmsg->("convert dgit import: upstream changes")
};
}
- $prline->("Import");
- $prprdelim->();
- my ($basis,$dummy) = walk
- $ovwr,
- $nogenerate, $report,
- 1, $depth+1;
- push @deb_cl, { ExactlyParents => [$basis] };
+ $prline->(" Import");
$rewrite_from_here->();
- last;
+ $upp_limit //= $#upp_cl; # further, deeper, patches discarded
+ die 'BUG $upp_limit is not used anywhere?';
+ $cur = $ovwr;
+ next;
} else {
# Everything is from this import. This kind of import
# is already in valid breakwater format, with the
# patches as commits.
printf $report " NoPM" if $report;
- push @deb_cl, { ExactlyParents => [$cur] };
# last thing we processed will have been the first patch,
# if there is one; which is fine, so no need to rewrite
# on account of this import
- $prline->("ImportOrigin");
- last;
+ $build_start->("ImportOrigin", $cur);
}
die "$ty ?";
} else {
}
}
$prprdelim->();
- if ($nogenerate) {
- return (undef, $basis);
- }
+ return if $nogenerate;
# Now we build it back up again
- workarea_fresh();
+ fresh_workarea();
my $rewriting = 0;
- my $build = $basis;
-
- my $rm_tree_cached = sub {
- my ($subdir) = @_;
- runcmd @git, qw(rm --quiet -rf --cached), $subdir;
- };
my $read_tree_debian = sub {
my ($treeish) = @_;
- $rm_tree_cached->(qw(debian));
- runcmd @git, qw(read-tree --prefix=debian/), "$treeish:debian";
+ read_tree_subdir 'debian', "$treeish:debian";
+ rm_subdir_cached 'debian/patches';
};
my $read_tree_upstream = sub {
my ($treeish) = @_;
my $committer_authline = calculate_committer_authline();
+ printdebug "WALK REBUILD $build ".(scalar @processed)."\n";
+
+ confess "internal error" unless $build eq (pop @processed)->{CommitId};
+
in_workarea sub {
mkdir $rd or $!==EEXIST or die $!;
my $current_method;
- foreach my $cl (qw(Debian), (reverse @deb_cl),
+ runcmd @git, qw(read-tree), $build;
+ foreach my $cl (qw(Debian), (reverse @brw_cl),
{ SpecialMethod => 'RecordBreakwaterTip' },
- qw(Upstream), (reverse @ups_cl)) {
+ qw(Upstream), (reverse @upp_cl)) {
if (!ref $cl) {
$current_method = $cl;
next;
my $method = $cl->{SpecialMethod} // $current_method;
my @parents = ($build);
my $cltree = $cl->{CommitId};
+ printdebug "WALK BUILD ".($cltree//'undef').
+ " $method (rewriting=$rewriting)\n";
if ($method eq 'Debian') {
$read_tree_debian->($cltree);
} elsif ($method eq 'Upstream') {
$rewriting = 1;
next;
} elsif ($method eq 'RecordBreakwaterTip') {
- last if $wantdebonly;
$breakwater = $build;
next;
} elsif ($method eq 'DgitImportDebianUpdate') {
$read_tree_debian->($cltree);
- $rm_tree_cached->(qw(debian/patches));
+ rm_subdir_cached qw(debian/patches);
} elsif ($method eq 'DgitImportUpstreamUpdate') {
$read_tree_upstream->($cltree);
push @parents, map { $_->{CommitId} } @{ $cl->{OrigParents} };
} else {
confess "$method ?";
}
- $rewriting ||= $cl ne pop @processed;
+ if (!$rewriting) {
+ my $procd = (pop @processed) // 'UNDEF';
+ if ($cl ne $procd) {
+ $rewriting = 1;
+ printdebug "WALK REWRITING NOW cl=$cl procd=$procd\n";
+ }
+ }
my $newtree = cmdoutput @git, qw(write-tree);
my $ch = $cl->{Hdr};
$ch =~ s{^tree .*}{tree $newtree}m or confess "$ch ?";
$ch =~ s{^parent .*\n}{}m;
$ch =~ s{(?=^author)}{
- map { "parent $_\n" } @parents
+ join '', map { "parent $_\n" } @parents
}me or confess "$ch ?";
if ($rewriting) {
$ch =~ s{^committer .*$}{$committer_authline}m
my $newcommit = cmdoutput @cmd;
confess "$ch ?" unless $rewriting or $newcommit eq $cl->{CommitId};
$build = $newcommit;
+ if (grep { $method eq $_ } qw(DgitImportUpstreamUpdate)) {
+ $last_upstream_update = $cur;
+ }
}
};
- runcmd @git, qw(diff-tree --quiet),
- map { $wantdebonly ? "$_:debian" : $_ }
- $input, $build;
+ my $final_check = get_differs $build, $input;
+ die sprintf "internal error %#x %s %s", $final_check, $build, $input
+ if $final_check & ~D_PAT_ADD;
- return ($build, $breakwater);
+ return ($build, $breakwater, $last_upstream_update);
}
sub get_head () { return git_rev_parse qw(HEAD); }
-sub update_head ($$) {
+sub update_head ($$$) {
+ my ($old, $new, $mrest) = @_;
+ runcmd @git, qw(update-ref -m), "debrebase: $mrest", 'HEAD', $new, $old;
+}
+
+sub update_head_checkout ($$$) {
my ($old, $new, $mrest) = @_;
- runcmd @git, qw(update-ref -m), "git-debrebase $mrest", $new, $old;
+ my $symref = git_get_symref();
+ runcmd @git, qw(checkout), $new, qw(.);
+ update_head $old, $new, $mrest;
}
sub cmd_launder () {
- badusage "no arguments to launder allowed";
+ badusage "no arguments to launder allowed" if @ARGV;
my $old = get_head();
my ($tip,$breakwater) = walk $old;
update_head $old, $tip, 'launder';
# no tree changes except debian/patches
- runcmd @git, qw(rm --quiet -rf debian/patches);
+ runcmd @git, qw(rm --quiet --ignore-unmatch -rf debian/patches);
printf "# breakwater tip\n%s\n", $breakwater;
+ printf "# working tip\n%s\n", $tip;
}
sub cmd_analyse () {
$old = get_head();
}
my ($dummy,$breakwater) = walk $old, 1,*STDOUT;
- print "$breakwater BREAKWATER\n";
STDOUT->error and die $!;
}
-my $toplevel = runcmd @git, qw(rev-parse --show-toplevel);
+sub cmd_new_upstream_v0 () {
+ # xxx would like to support more git-rebase options
+ badusage
+ "need NEW-VERSION UPS-COMMITISH [EXTRA-UPS-NAME EXTRA-UPS-COMMITISH...]"
+ unless @ARGV % 2 == 0 and @ARGV >= 2;
+ # tree should be clean and this is not checked
+ # automatically and unconditionally launders before rebasing
+ # if rebase --abort is used, laundering has still been done
+
+ my %pieces;
+
+ # parse args - low commitment
+ my $new_version = (new Dpkg::Version scalar(shift @ARGV), check => 1);
+ my $new_upstream_version = $new_version->version();
+
+ my $new_upstream = git_rev_parse shift @ARGV;
+
+ my $piece = sub {
+ my ($n, @x) = @_; # may be ''
+ my $pc = $pieces{$n} //= {
+ Name => $n,
+ Desc => ($n ? "upstream piece $n" : "upstream (main piece"),
+ };
+ while (my $k = shift @x) { $pc->{$k} = shift @x; }
+ };
+
+ my @newpieces;
+ my $newpiece = sub {
+ my ($n, @x) = @_; # may be ''
+ my $pc = $piece->($n, @x, NewIx => (scalar @newpieces));
+ push @newpieces, $pc;
+ };
+
+ $newpiece->('',
+ OldIx => 0,
+ New => $new_upstream,
+ );
+ while (@ARGV) {
+ my $n = shift @ARGV;
+ my $c = git_rev_parse shift @ARGV;
+ die unless $n =~ m/^$extra_orig_namepart_re$/;
+ $newpiece->($n, New => $c);
+ }
+
+ # now we need to investigate the branch this generates the
+ # laundered version but we don't switch to it yet
+ my $old_head = get_head();
+ my ($old_laundered_tip,$old_bw,$old_upstream_update) = walk $old_head;
+
+ my $old_bw_cl = classify $old_bw;
+ my $old_upstream_update_cl = classify $old_upstream_update;
+ confess unless $old_upstream_update_cl->{OrigParents};
+ my $old_upstream = parsecommit
+ $old_upstream_update_cl->{OrigParents}[0]{CommitId};
+
+ my $problems = 0;
+ my $problem = sub {
+ my ($msg) = @_;
+ $problems++;
+ print STDERR "preflight check failed: $msg\n";
+ };
+
+ $piece->('', Old => $old_upstream);
+
+ if ($old_upstream->{Msg} =~ m{^\[git-debrebase }m) {
+ if ($old_upstream->{Msg} =~
+ m{^\[git-debrebase new-upstream combine \.((?: $extra_orig_namepart_re)+)\]}
+ ) {
+ my @oldpieces = ('', split / /, $1);
+ my $parentix = -1 + scalar @{ $old_upstream->{Parents} };
+ foreach my $i (0..$#oldpieces) {
+ my $n = $oldpieces[$i];
+ $piece->($n, Old => $old_upstream->{CommitId}.'^'.$parentix);
+ }
+ } else {
+ $problem->("previous upstream $old_upstream->{CommitId} is from".
+ " git-debrebase but not a \`new-upstream combine' commit");
+ }
+ }
+
+ foreach my $pc (values %pieces) {
+ if (!$pc->{Old}) {
+ $problem->("introducing upstream piece $pc->{Name}");
+ } elsif (!$pc->{New}) {
+ $problem->("dropping upstream piece $pc->{Name}");
+ } elsif (!is_fast_fwd $pc->{Old}, $pc->{New}) {
+ $problem->("not fast forward: $pc->{Name} $pc->{Old}..$pc->{New}");
+ }
+ }
+
+ if ($problems) {
+ if ($opt_force) {
+ printf STDERR
+ "preflight check failures (%d) overriden by --force\n",
+ $problems;
+ } else {
+ fail sprintf
+ "preflight check failures (%d) (you could --force)",
+ $problems;
+ }
+ }
+
+ my $new_bw;
+
+ fresh_workarea();
+ in_workarea sub {
+ my @upstream_merge_parents;
+
+ if (!$problems) {
+ push @upstream_merge_parents, $old_upstream->{CommitId};
+ }
+
+ foreach my $pc (@newpieces) { # always has '' first
+ if ($pc->{Name}) {
+ read_tree_subdir $pc->{Name}, $pc->{New};
+ } else {
+ runcmd @git, qw(read-tree), $pc->{New};
+ }
+ push @upstream_merge_parents, $pc->{New};
+ }
+
+ # index now contains the new upstream
+
+ if (@newpieces > 1) {
+ # need to make the upstream subtree merge commit
+ my $us_tree = cmdoutput @git, qw(write-tree);
+ my @cmd = (@git, qw(commit-tree), $us_tree);
+ push @cmd, qw(-p), $_ foreach @upstream_merge_parents;
+ push @cmd, qw(-m), "Combine upstreams for $new_upstream_version";
+ push @cmd, qw(-m),
+ "[git-debrebase new-upstream combine . ".
+ (join " ", map { $_->{Name} } @newpieces[1..$#newpieces]).
+ "]";
+ $new_upstream = cmdoutput @cmd;
+ }
+
+ # $new_upstream is either the single upstream commit, or the
+ # combined commit we just made. Either way it will be the
+ # "upstream" parent of the breakwater special merge.
+
+ read_tree_subdir 'debian', "$old_bw:debian";
+
+ # index now contains the breakwater merge contents
+
+ my $bw_tree = cmdoutput @git, qw(write_tree);
+ my @cmd = (@git, qw(commit-tree), $bw_tree);
+ push @cmd, qw(-p), $old_bw, qw(-p), $new_upstream;
+ push @cmd, qw(-m), "Update to upstream $new_upstream_version";
+ push @cmd, qw(-m),
+ "[git-debrebase new-upstream breakwater $new_upstream_version]";
+ $new_bw = cmdoutput @git;
+
+ # Now we have to add a changelog stanza so the Debian version
+ # is right.
+
+ die if unlink "debian";
+ die unless $!==ENOTEMPTY;
+ unlink "debian/changelog" or die $!;
+ open CN, ">", "debian/changelog" or die $!;
+ my $oldclog = git_cat_file ":debian/changelog";
+ $oldclog =~ m/^($package_re) \(\S+\) / or
+ fail "cannot parse old changelog to get package name";
+ my $p = $1;
+ print CN <<END, $oldclog or die $!;
+$p ($new_version) UNRELEASED; urgency=medium
+
+ * Update to new upstream version $new_upstream_version.
+
+ --
+
+END
+ close CN or die $!;
+ runcmd @git, qw(update-index --add --replace), 'debian/changelog';
+
+ # Now we have the final new breakwater branch in the index
+
+ $bw_tree = cmdoutput @git, qw(write_tree);
+ @cmd = (@git, qw(commit-tree), $bw_tree);
+ push @cmd, qw(-p), $new_bw;
+ push @cmd, qw(-m),
+ "Update changelog for new upstream $new_upstream_version";
+ push @cmd, qw(-m),
+ "[git-debrebase new-upstream changelog $new_upstream_version]";
+ $new_bw = cmdoutput @git;
+ };
+
+ # we have constructed the new breakwater. we now need to commit to
+ # the laundering output, because git-rebase can't easily be made
+ # to make a replay list which is based on some other branch
+
+ update_head $old_head, $old_laundered_tip, 'launder for new upstream';
+
+ my @cmd = (@git, qw(rebase --onto), $new_bw, $old_bw);
+ runcmd @cmd;
+ # now it's for the user to sort out
+}
+
+sub cmd_downstream_rebase_launder_v0 () {
+ badusage "needs 1 argument, the baseline" unless @ARGV==1;
+ my ($base) = @ARGV;
+ $base = git_rev_parse $base;
+ my $old_head = get_head();
+ my $current = $old_head;
+ my $topmost_keep;
+ for (;;) {
+ if ($current eq $base) {
+ $topmost_keep //= $current;
+ print " $current BASE stop\n";
+ last;
+ }
+ my $cl = classify $current;
+ print " $current $cl->{Type}";
+ my $keep = 0;
+ my $p0 = $cl->{Parents}[0]{CommitId};
+ my $next;
+ if ($cl->{Type} eq 'Pseudomerge') {
+ print " ^".($cl->{Contributor}{Ix}+1);
+ $next = $cl->{Contributor}{CommitId};
+ } elsif ($cl->{Type} eq 'AddPatches' or
+ $cl->{Type} eq 'Changelog') {
+ print " strip";
+ $next = $p0;
+ } else {
+ print " keep";
+ $next = $p0;
+ $keep = 1;
+ }
+ print "\n";
+ if ($keep) {
+ $topmost_keep //= $current;
+ } else {
+ die "to-be stripped changes not on top of the branch\n"
+ if $topmost_keep;
+ }
+ $current = $next;
+ }
+ if ($topmost_keep eq $old_head) {
+ print "unchanged\n";
+ } else {
+ print "updating to $topmost_keep\n";
+ update_head_checkout
+ $old_head, $topmost_keep,
+ 'downstream-rebase-launder-v0';
+ }
+}
+
+GetOptions("D+" => \$debuglevel,
+ 'force!') or die badusage "bad options\n";
+initdebug('git-debrebase ');
+enabledebug if $debuglevel;
+
+my $toplevel = cmdoutput @git, qw(rev-parse --show-toplevel);
chdir $toplevel or die "chdir $toplevel: $!";
+$rd = fresh_playground "$playprefix/misc";
+
my $cmd = shift @ARGV;
my $cmdfn = $cmd;
$cmdfn =~ y/-/_/;