# You should have received a copy of the GNU General Public License
# along with this program. If not, see <http://www.gnu.org/licenses/>.
+# usages:
+# git-debrebase launder # prints breakwater tip
+# git-debrebase analyse
+# git-debrebase start # like ffrebase start + debrebase launder
+# git-debrebase create-new-upstream [-f] <upstreaminfo>
+# git-debrebase new-upstream [-f] <upstreaminfo>
+# git-debrebase <git-rebase options> # does debrebase start if necessary
+#
+# <upstreaminfo> is
+# [,][<subdir>:][+]<commitid>[,...]
+#
+# if initial comma is supplied, entries are not positional. Unspecified
+# <subdir> means root (and there may be only one).
+# xxx want auto branch names
+# xxx too complicated
+# how about for now
+# [+]<commit> [<subdir:> [+]<commit>...]
+# ? plus options
+# --new-upstream-different-subtrees
+
+# UPSTREAM[,[[SUBDIR:]SUBUPSTREAM]
+# default for SUBDIR: is from previous upstream merge[xxx terminology]
+#
+#
+#xxx
+# when starting must record original start (for ff)
+# and new rebase basis
+#
+# git-ffrebase start [BASE] # records previous HEAD so it can be overwritten
+# # records base for future git-ffrebase
+# git-ffrebase set-base BASE
+# git-ffrebase <git-rebase options>
+# git-ffrebase finish
+# git-ffrebase status [BRANCH]
+#
+# refs/ffrebase-prev/BRANCH BRANCH may be refs/...; if not it means
+# refs/ffrebase-base/BRANCH refs/heads/BRANCH
+# zero, one, or both of these may exist
+
use strict;
+
use Memoize;
+use Data::Dumper;
-use Debian::Dgit;
+use Debian::Dgit qw(:DEFAULT $wa);
sub cfg ($) {
my ($k) = @_;
memoize('cfg');
-use Data::Dumper;
-print Dumper(cfg('wombat.foo.bar'));
+sub get_commit ($) {
+ my ($objid) = @_;
+ my ($type,$data) = git_cat_file $objid;
+ die unless $type eq 'commit';
+ $data =~ m/(?<=\n)\n/;
+ return ($`,$');
+}
+
+sub D_DEB () { return 0x1; }
+sub D_UPS () { return 0x2; }
+sub D_PAT_ADD () { return 0x4; }
+sub D_PAT_OTH () { return 0x8; }
+
+our $rd = ".git/git-debrebase";
+our $ud = "$rd/work";
+
+sub commit_pr_info ($) {
+ my ($r) = @_;
+ return Data::Dumper->dump([$r], [qw(commit)]);
+}
+
+sub calculate_committer_authline () {
+ my $c = cmdoutput @git, qw(commit-tree --no-gpg-sign -m),
+ 'XXX DUMMY COMMIT (git-debrebase)', "$basis:";
+ my ($h,$m) = get_commit $c;
+ $h =~ m/^committer .*$/m or confess "($h) ?";
+ return $&;
+}
+
+sub classify ($) {
+ my ($objid) = @_;
+
+ my ($h,$m) = get_commit $objid;
+
+ my ($t) = $h =~ m/^tree (\w+)$/m or die $cur;
+ my (@ph) = $h =~ m/^parent (\w+)$/m;
+ my @p;
+
+ my $r = {
+ CommitId => $objid,
+ Hdr => $hdr,
+ Msg => $m,
+ Tree => $t,
+ Parents => \@p,
+ };
+
+ foreach my $ph (@ph) {
+ push @p, {
+ Ix => $#p,
+ CommitId => $ph,
+ Differs => (get_differs $t, $ph),
+ };
+ }
+
+ my $classify = sub {
+ my ($type, @rest) = @_;
+ $r = { %r, Type => $type, @rest };
+ return $r;
+ };
+ my $unknown = sub {
+ my ($why) = @_;
+ $r = { %r, Type => Unknown };
+ return $r;
+ }
+
+ if (@p == 1) {
+ my $d = $r->{Parents}[0]{Differs};
+ if ($d == D_DPAT_ADD) {
+ return $classify->(qw(AddPatches));
+ } elsif ($d & (D_DPAT_ADD|D_DPAT_OTH)) {
+ return $unknown->("edits debian/patches");
+ } elsif ($d == D_DEB) {
+ return $classify->(qw(Packaging));
+ } elsif ($d == D_UPS) {
+ return $classify->(qw(Upstream));
+ } elsif ($d == D_DEB|D_UPS) {
+ return $classify->(qw(Mixed));
+ } elsif ($d == 0) {
+ return $unknown->("no changes");
+ } else {
+ confess "internal error $objid ?";
+ }
+ }
+ if (!@p) {
+ return $unknown->("origin commit");
+ }
+
+ my @identical = grep { !$_->{Differs} } @p;
+ if (@p == 2 && @identical == 1) {
+ my @overwritten = grep { $_->{Differs} } @p;
+ confess "internal error $objid ?" unless @overwritten==1;
+ return $classify->(qw(Pseudomerge),
+ Overwritten => $overwritten[0],
+ Contributor => $identical[0]);
+ }
+ if (@p == 2 && @identical == 2) {
+ my @bytime = nsort_by {
+ my ($ph,$pm) = get_commit $_->{CommitId};
+ $ph =~ m/^committer .* (\d+) [-+]\d+$/m or die "$_->{CommitId} ?";
+ $1;
+ } @p;
+ return $classify->(qw(Pseudomerge),
+ SubType => qw(Ambiguous),
+ Overwritten => $bytime[0],
+ Contributor => $bytime[1]);
+ }!
+ foreach my $p (@p) {
+ my ($p_h, $p_m) = get_commit $p;
+ $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' };
+ my $m2 = $m;
+ if (!(grep { !$_->{IsOrigin} } @p) and
+ (@origs >= @p - 1) and
+ $m2 =~ s{^\[(dgit import unpatched .*)\]$}{[was: $1]}m) {
+ $r->{NewMsg} = $m2;
+ return $classify->(qw(DgitImportUnpatched),
+ OrigParents => \@orig_ps);
+ }
+
+ my ($stype, $series) = git_cat_file "$t:debian/patches/series";
+ my $haspatches = $stype ne 'missing' && $series =~ m/^\s*[^#\n\t ]/m;
+
+ # How to decide about l/r ordering of breakwater merges ? git
+ # --topo-order prefers to expand 2nd parent first. There's
+ # already an easy rune to look for debian/ history anyway (git log
+ # debian/) so debian breakwater branch should be 1st parent; that
+ # way also there's also an easy rune to look for the upstream
+ # patches (--topo-order).
+ if (@p == 2 &&
+ !$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),
+ Upstream => $p[1]);
+ }
+
+ return $unknown->("complex merge");
+}
+
+sub launder ($$$) {
+ my ($input, $pseudos_must_overwrite_this, $wantdebonly) = @_;
+ # go through commits backwards
+ # we generate two lists of commits to apply
+ my (@deb_cl, @ups_cl, @processed);
+ my %found;
+ my @pseudomerges;
+
+ my $cl;
+ my $xmsg = sub {
+ my ($appendinfo) = @_;
+ my $ms = $cl->{Msg};
+ chomp $ms;
+ $ms .= "\n\n[git-debrebase $appendinfo]\n";
+ return (Msg => $ms);
+ };
+ my $rewrite_from_here = sub {
+ push @processed, { SpecialMethod => 'StartRewrite' };
+ };
+
+ my $cur = $input;
+
+ for (;;) {
+ $cl = classify $cur;
+ my $ty = $cl->{Type};
+ my $st = $cl->{SubType};
+ $found{$ty. ( defined($st) ? "-$st" : '' )}++;
+ my $p0 = $cl->{Parents}[0]{CommitId};
+ if ($ty eq 'AddPatches') {
+ $cur = $p0;
+ $rewrite_from_here->();
+ next;
+ } elsif ($ty eq 'Packaging') {
+ push @deb_cl, $cl;
+ push @processed, $cl;
+ $cur = $p0;
+ next;
+ } elsif ($ty eq 'Upstream') {
+ push @ups_cl, $cl;
+ push @processed, $cl;
+ $cur = $p0;
+ next;
+ } elsif ($ty eq 'Mixed') {
+ my $queue = sub {
+ my ($q, $wh) = @_;
+ my $cls = { $cl, $xmsg->("split mixed commit: $wh part") };
+ push @$q, $cls;
+ };
+ $queue->(\@deb_cl, "debian");
+ $queue->(\@ups_cl, "upstream");
+ $rewrite_from_here->();
+ next;
+ } elsif ($ty eq 'Pseudomerge') {
+ if (defined $pseudos_must_overwrite_this) {
+ confess 'xxx actually check this';
+ }
+ push @pseudomerges, $cl;
+ $rewrite_from_here->();
+ $cur = $ty->{Contributor};
+ next;
+ } elsif ($ty eq 'BreakwaterUpstreamMerge') {
+ $basis = $cur;
+ last;
+ } elsif ($ty eq 'DgitImportUnpatched' &&
+ @pseudomerges == 1) {
+ # This import has a tree which is just like a breakwater
+ # tree, but it has the wrong history. Its ought to have
+ # the previous breakwater (which dgit ought to have
+ # generated a pseudomerge to overwrite) as an ancestor.
+ # That will make the history of the debian/ files correct.
+ # As for the upstream version: either it's the same upstream
+ # as the previous breakwater, in which case that history is
+ # precisely right. 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.
+ if ($differs & D_UPS) {
+ push @deb_cl, {
+ %r,
+ SpecialMethod => 'DgitImportUpstreamUpdate',
+ $xmsg->("convert dgit import: debian changes")
+ };
+ }
+ push @deb_cl, {
+ %r,
+ SpecialMethod => 'DgitImportDebianUpdate',
+ $xmsg->("convert dgit import: upstream changes")
+ };
+ my $differs = get_differs $previous_breakwater, $cl->{Tree};
+ $basis = launder $pseudomerges[0]{Overwritten}, undef, 1;
+ $rewrite_from_here->();
+ last;
+ } else {
+ die "Reached difficult commit $cur: ".Dumper($cl);
+ }
+ }
+ # Now we build it back up again
+
+ workarea_fresh();
+ in_workarea sub { xxx attributes xxx };
+
+ my $rewriting = 1;
+
+ 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";
+ };
+ my $read_tree_upstream = sub {
+ my ($treeish) = @_;
+ runcmd @git, qw(read-tree), $treeish;
+ $read_tree_debian->($build);
+ };
+
+ my $committer_authline = calculate_committer_authline();
+
+ in_workarea sub {
+ mkdir $rd or $!==EEXIST or die $!;
+ my $current_method;
+ foreach my $cl (qw(Debian), (reverse @deb_cl),
+ { SpecialMethod => 'RecordBreakwaterTip' },
+ qw(Upstream), (reverse @ups_cl)) {
+ if (!ref $cl) {
+ $current_method = $cl;
+ next;
+ }
+ $method = $cl->{SpecialMethod} // $current_method;
+ my @parents = ($build);
+ my $cltree = $cl->{CommitId}
+ if ($method eq 'Debian') {
+ $read_tree_debian->($cltree);
+ } elsif ($method eq 'Upstream') {
+ $read_tree_upstream->($cltree);
+ } elsif ($method eq 'StartRewrite') {
+ $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));
+ } elsif ($method eq 'DgitImportUpstreamUpdate') {
+ $read_tree_upstream->($cltree);
+ push @parents, map { $_->{CommitId} } @{ $cl->{OrigParents} };
+ } else {
+ confess "$method ?";
+ }
+ $rewriting ||= $cl ne pop @processed;
+ 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
+ }me or confess "$ch ?";
+ if ($rewrite) {
+ $ch =~ s{^committer .*$}{$committer_authline}m
+ or confess "$ch ?";
+ }
+ my $cf = "$rd/m$rewrite"
+ open CD, ">", $cf or die $!;
+ print CD $ch, "\n", $cl->{Msg}; or die $!;
+ close CD or die $!;
+ my @cmd = (@git, qw(hash-object));
+ push @cmd, qw(-w) if $rewrite;
+ push @cmd, qw(-t commit), $cf;
+ my $newcommit = cmdoutput @cmd;
+ confess "$ch ?" unless $rewrite or $newcommit eq $cl->{CommitId};
+ $build = $newcommit;
+ }
+ };
+
+ runcmd @git, qw(diff-tree --quiet),
+ map { $wantdebonly ? "$_:debian" : $_ },
+ $input, $build;
+
+ return ($build, $breakwater);
+}
+
+sub get_head () { return git_rev_parse qw(HEAD); }
+
+sub update_head ($$) {
+ my ($old, $new, $mrest) = @_;
+ runcmd @git, qw(update-ref -m), "git-debrebase $mrest", $new, $old;
+}
+
+sub cmd_launder () {
+ my $old = get_head();
+ my ($tip,$breakwater) = launder $old, 0, undef, 0;
+ update_head $old, $tip, 'launder'; # no tree changes!
+ printf "# breakwater tip:\n%s\n", $breakwater;
+}
+
+my $toplevel = runcmd @git, qw(rev-parse --show-toplevel);
+chdir $toplevel or die "chdir $toplevel: $!";
+
+my $cmd = shift @ARGV;
+my $cmdfn = $cmd;
+$cmdfn =~ y/-/_/;
+$cmdfn = ${*::}{"cmd_$cmdfn"};
+
+$cmdfn or badusage "unknown git-debrebase sub-operation $cmd";
+$cmdfn->();
~ianmdlvl / dgit.git / blobdiff