rm_subdir_cached 'debian/patches';
}
+sub read_tree_upstream ($;$) {
+ my ($treeish, $keep_patches) = @_;
+ my $save = cmdoutput @git, qw(write-tree --prefix=debian/);
+ runcmd @git, qw(read-tree), $treeish;
+ read_tree_subdir 'debian', $save;
+ rm_subdir_cached 'debian/patches' unless $keep_patches;
+};
+
sub make_commit ($$) {
my ($parents, $message_paras) = @_;
my $tree = cmdoutput @git, qw(write-tree);
runcmd @git, qw(add -f debian/patches);
}
+
+# xxx allow merge separately from laundering
+#
+# xxx docs highlight forbidden things
+# xxx docs list allowable things ?
+# xxx docs explicitly forbid some rebase
+#
+# xxx provide a way for the user to help
+# xxx (eg, provide wreckage provide way to continue)
+
+# later/rework?
+# use git-format-patch?
+# our own patch identification algorithm?
+# this is an alternative strategy
+
+sub merge_series ($$;@) {
+ my ($newbase, $base_q, @input_qs) = @_;
+ # $base_q{SeriesBase} $input_qs[]{SeriesBase}
+ # $base_q{SeriesTip} $input_qs[]{SeriesTip}
+ # ^ specifies several patch series (currently we only support exactly 2)
+ # return value is a commit which is the result of
+ # merging the two versions of the same topic branch
+ # $input_q[0] and $input_q[1]
+ # with respect to the old version
+ # $base_q
+ # all onto $newbase.
+
+ # Creates, in *_q, a key MR for its private use
+
+ $input_qs[$_]{MR}{S} = $_ foreach (0..$#input_qs);
+ $base_q->{MR}{S} = 'base';
+
+ my %prereq;
+ # $prereq{<patch filename>}{<possible prereq}{<S>} = 1 or absent
+ # $prereq{<patch filename>}{<possible prereq} exists or not (later)
+ # $prereq{<patch filename>} exists or not (even later)
+
+ my $result;
+
+ local $workarea = fresh_playground "$playprefix/merge";
+ my $seriesfile = "debian/patches/series";
+ in_workarea sub {
+ playtree_setup();
+ foreach my $q ($base_q, reverse @input_qs) {
+ my $s = $q->{MR}{S};
+ gbp_pq_export "p-$s", $q->{SeriesBase}, $q->{SeriesTip};
+ if (open S, $seriesfile) {
+ my @earlier;
+ while (my $patch = <S>) {
+ chomp $patch or die $!;
+ foreach my $earlier (@earlier) {
+ $prereq{$patch}{$earlier}{$s}++ and die;
+ }
+ push @earlier, $patch;
+ stat "debian/patches/$patch" or die "$patch ?";
+ }
+ S->error and die "$seriesfile $!";
+ close S;
+ } else {
+ die "$seriesfile $!" unless $!==ENOENT;
+ }
+ read_tree_upstream $newbase, 1;
+ my $pec = make_commit [ grep { defined } $base_q->{MR}{PEC} ], [
+ "Convert $s to patch queue for merging",
+ "[git-debrebase merge-innards patch-queue import:".
+ " $q->{SeriesTip}]"
+ ];
+ runcmd @git, qw(rm -q --cached), $seriesfile;
+ $pec = make_commit [ $pec ], [
+ "Drop series file from $s to avoid merge trouble",
+ "[git-debrebase merge-innards patch-queue prep:".
+ " $q->{SeriesTip}]"
+ ];
+ runcmd @git, qw(reset -q --hard), $pec;
+ $q->{MR}{PEC} = $pec;
+ }
+ # now, because of reverse, we are on $input_q->{MR}{OQC}
+ runcmd @git, qw(checkout -q -b merge);
+ my @mergecmd = (@git, qw(merge --quiet --no-edit), "p-1");
+ debugcmd '+', @mergecmd;
+ $!=0; $?=-1;
+ if (system @mergecmd) {
+ failedcmd @mergecmd;
+ }
+
+ # We need to construct a new series file
+ # Firstly, resolve prereq
+ foreach my $f (keys %prereq) {
+ if (!stat_exists "debian/patches/$f") {
+ # git merge deleted it; that's how we tell it's not wanted
+ delete $prereq{$f};
+ next;
+ }
+ foreach my $g (keys %{ $prereq{$f} }) {
+ my $gfp = $prereq{$f}{$g};
+ next unless
+ # want to keep it
+ !!$gfp->{0} == !!$gfp->{1}
+ ? $gfp->{0}
+ : !$gfp->{base}
+ ;
+ delete $prereq{$f}{$g};
+ }
+ }
+
+ my $unsat = sub {
+ my ($f) = @_;
+ return scalar keys %{ $prereq{$f} };
+ };
+
+ my $nodate = time + 1;
+ my %authordate;
+ # $authordate{<patch filename>};
+ my $authordate = sub {
+ my ($f) = @_;
+ $authordate{$f} //= do {
+ open PF, "<", "debian/patches/$f" or die "$f $!";
+ while (<PF>) {
+ return $nodate if m/^$/;
+ last if s{^Date: }{};
+ }
+ chomp;
+ return cmdoutput qw(date +%s -d), $_;
+ };
+ };
+
+ open NS, '>', $seriesfile or die $!;
+
+ while (keys %prereq) {
+ my $best;
+ foreach my $try (sort keys %prereq) {
+ if ($best) {
+ next if (
+ $unsat->($try) <=> $unsat->($best) or
+ $authordate->($try) <=> $authordate->($best) or
+ $try cmp $best
+ ) >= 0;
+ }
+ $best = $try;
+ }
+ print NS "$best\n" or die $!;
+ delete $prereq{$best};
+ foreach my $gp (values %prereq) {
+ delete $gp->{$best};
+ }
+ }
+
+ runcmd @git, qw(add), $seriesfile;
+ runcmd @git, qw(commit --quiet -m), 'Merged series';
+
+ runcmd qw(gbp pq import);
+
+ # OK now we are on patch-queue/merge, and we need to rebase
+ # onto the intended parent and drop the patches from each one
+
+ my $build = $newbase;
+ my @lcmd = (@git, qw(rev-list --reverse merge..patch-queue/merge));
+ foreach my $c (grep /./, split /\n/, cmdoutput @lcmd) {
+ my $commit = git_cat_file $c, 'commit';
+ read_tree_upstream $c;
+ my $tree = cmdoutput @git, qw(write-tree);
+ $commit =~ s{^parent (\S+)$}{parent $build}m or confess;
+ $commit =~ s{^tree (\S+)$}{tree $tree}m or confess;
+ open C, ">", "../mcommit" or die $!;
+ print C $commit or die $!;
+ close C or die $!;
+ $build = cmdoutput @git, qw(hash-object -w -t commit ../mcommit);
+ }
+ $result = $build;
+ runcmd @git, qw(update-ref refs/heads/result), $result;
+ };
+ printdebug "merge_series returns $result\n";
+ return $result;
+}
+
# classify returns an info hash like this
# CommitId => $objid
# Hdr => # commit headers, including 1 final newline
OrigParents => \@orig_ps);
}
- return $unknown->("complex merge");
+ if (@p > 2) {
+ return $unknown->("octopus merge");
+ }
+ if (@p == 2 and
+ $r->{Msg} =~ m{^\[git-debrebase merged-breakwater.*\]$}m) {
+ return $classify->("MergedBreakwaters");
+ }
+ if ($r->{Msg} =~ m{^\[(git-debrebase|dgit)[: ].*\]$}m) {
+ return $unknown->("unknown kind of merge from $1");
+ }
+
+ if (!$ENV{GIT_DEBREBASE_EXPERIMENTAL_MERGE}) {
+ return $unknown->("general two-parent merge");
+ }
+
+ return $classify->("VanillaMerge");
}
sub keycommits ($;$$$$) {
" ($head)");
return (undef,undef);
}
+ } elsif ($ty eq 'VanillaMerge') {
+ $x->($trouble, 'vanillamerge',
+ "found vanilla merge"," ($head)");
+ return (undef,undef);
} else {
$x->($fatal, 'unprocessable',
"found unprocessable commit, cannot cope: $cl->{Why}",
no warnings qw(exiting); last;
};
+ my $nomerge = sub {
+ fail "something useful about failed merge attempt @_ xxx".Dumper($cl);
+ };
+
my $last_anchor;
for (;;) {
return $bomb->();
}
die "$ty ?";
+ } elsif ($ty eq 'VanillaMerge' or $ty eq 'MergedBreakwaters') {
+ # xxx need to handle ffq if one side was unstitched
+ # wait both of them may be!
+ my $ok=1;
+ my $best_anchor;
+ # We expect to find a dominating anchor amongst the
+ # inputs' anchors. That will be the new anchor.
+ #
+ # More complicated is finding a merge base for the
+ # breakwaters. We need a merge base that is a breakwater
+ # commit. The ancestors of breakwater commits are more
+ # breakwater commits and possibly upstream commits and the
+ # ancestors of those upstream. Upstreams might have
+ # arbitrary ancestors. But any upstream commit U is
+ # either included in both anchors, in which case the
+ # earlier anchor is a better merge base than any of U's
+ # ancestors; or U is not included in the older anchor, in
+ # which case U is not an ancestor of the vanilla merge at
+ # all. So no upstream commit, nor any ancestor thereof,
+ # is a best merge base. As for non-breakwater Debian
+ # commits: these are never ancestors of any breakwater.
+ #
+ # So any best merge base as found by git-merge-base
+ # is a suitable breakwater anchor. Usually there will
+ # be only one.
+
+ printdebug "*** MERGE\n";
+
+ # xxx avoid calling walk without nogenerate when
+ # we have a MergedBreakwater; instead call keycommits ?
+
+ my @bwbcmd = (@git, qw(merge-base));
+ my @ibcmd = (@git, qw(merge-base --all));
+ my $might_be_in_bw = 1;
+
+ my $ps = $cl->{Parents};
+
+ foreach my $p (@$ps) {
+ $prline->(" VanillaMerge ".$p->{Ix});
+ $prprdelim->();
+ my ($ptip, $pbw, $panchor) =
+ walk $p->{CommitId}, 0, $report,
+ $report_lprefix.' ';
+ $p->{Laundered} = $p->{SeriesTip} = $ptip;
+ $p->{Breakwater} = $p->{SeriesBase} = $pbw;
+ $p->{Anchor} = $panchor;
+
+ $best_anchor = $panchor if
+ !defined $best_anchor or
+ is_fast_fwd $best_anchor, $panchor;
+
+ printdebug " MERGE BA best=".($best_anchor//'-').
+ " p=$panchor\n";
+ }
+
+ foreach my $p (@$ps) {
+ $prline->(" VanillaMerge ".$p->{Ix});
+ if (!is_fast_fwd $p->{Anchor}, $best_anchor) {
+ $nomerge->('DivergentAnchor');
+ } elsif ($p->{Anchor} eq $best_anchor) {
+ print $report " SameAnchor" if $report;
+ } else {
+ print $report " SupersededAnchor" if $report;
+ }
+ if ($p->{Breakwater} eq $p->{CommitId}) {
+ # this parent commit was its own breakwater,
+ # ie it is part of the breakwater
+ print $report " Breakwater" if $report;
+ } else {
+ $might_be_in_bw = 0;
+ }
+ push @bwbcmd, $p->{Breakwater};
+ push @ibcmd, $p->{CommitId};
+ }
+
+ if ($ok && $might_be_in_bw) {
+ $prline->(" VanillaMerge MergedBreakwaters");
+ $last_anchor = $best_anchor;
+ $build_start->('MergedBreakwaters', $cur);
+ }
+
+ $nomerge->("alleged merged-breakwater is not a breakwater")
+ unless $ty eq 'VanillaMerge';
+
+ my $bwb = cmdoutput @bwbcmd;
+
+ # OK, now we have a breakwater base, but we need the merge
+ # base for the interchange branch because we need the delta
+ # queue.
+ #
+ # This a the best merge base of our inputs which has the
+ # breakwater merge base as an ancestor.
+
+ my @ibs =
+ grep { is_fast_fwd $bwb, $_ }
+ grep /./,
+ split /\n/,
+ cmdoutput @ibcmd;
+ my ($ib) = @ibs
+ or $nomerge->("no suitable interchange merge base");
+
+ $prline->(" VanillaMerge Base");
+ $prprdelim->();
+ my ($btip, $bbw, $banchor) =
+ walk $ib, 0, $report, $report_lprefix.' ';
+
+ my $ibinfo = { SeriesTip => $btip,
+ SeriesBase => $bbw,
+ Anchor => $banchor };
+ $bbw eq $bwb
+ or $nomerge->("interchange merge-base ($ib)'s".
+ " breakwater ($bbw)".
+ " != breakwaters' merge-base ($bwb)");
+ grep { $_->{Anchor} eq $ibinfo->{Anchor} } @$ps
+ or $nomerge->("interchange merge-base ($ib)'s".
+ " anchor ($ibinfo->{SeriesBase})".
+ " != any merge input's anchor (".
+ (join ' ', map { $_->{Anchor} } @$ps).
+ ")");
+
+
+ $cl->{MergeInterchangeBaseInfo} = $ibinfo;
+ $cl->{MergeBestAnchor} = $best_anchor;
+ push @brw_cl, {
+ %$cl,
+ SpecialMethod => 'MergeCreateMergedBreakwaters',
+ $xmsg->('construct merged breakwater from vanilla merge'),
+ };
+ push @upp_cl, {
+ %$cl,
+ SpecialMethod => 'MergeMergeSeries',
+ };
+ $build_start->('MergeBreakwaters', $cur);
} else {
printdebug "*** WALK BOMB unrecognised\n";
return $bomb->();
my $rewriting = 0;
- my $read_tree_upstream = sub {
- my ($treeish) = @_;
- runcmd @git, qw(read-tree), $treeish;
- read_tree_debian($build);
- };
-
$#upp_cl = $upp_limit if defined $upp_limit;
my $committer_authline = calculate_committer_authline();
if ($method eq 'Debian') {
read_tree_debian($cltree);
} elsif ($method eq 'Upstream') {
- $read_tree_upstream->($cltree);
+ read_tree_upstream($cltree);
} elsif ($method eq 'StartRewrite') {
$rewriting = 1;
next;
confess unless $rewriting;
my $differs = (get_differs $build, $cltree);
next unless $differs & D_UPS;
- $read_tree_upstream->($cltree);
+ read_tree_upstream($cltree);
push @parents, map { $_->{CommitId} } @{ $cl->{OrigParents} };
+ } elsif ($method eq 'MergeCreateMergedBreakwaters') {
+ print "Found a general merge, will try to tidy it up.\n";
+ $rewriting = 1;
+ read_tree_upstream($cl->{MergeBestAnchor});
+ read_tree_upstream($cl->{MergeBestAnchor});
+ read_tree_debian($cltree);
+ @parents = map { $_->{Breakwater} } @{ $cl->{Parents} };
+ } elsif ($method eq 'MergeMergeSeries') {
+ print "Running merge resolution for $cl->{CommitId}...\n";
+ $build = merge_series
+ $build,
+ $cl->{MergeInterchangeBaseInfo},
+ @{ $cl->{Parents} };
+ $last_anchor = $cl->{MergeBestAnchor};
+ # xxx need to check the tree somehow
+ print "Merge resolution successful.\n";
+ next;
} else {
confess "$method ?";
}
push @deferred_updates, "update $ffq_prev $currentval $git_null_obj";
push @deferred_updates, "delete $gdrlast";
- push @deferred_update_messages, "Recorded current head for preservation";
+ push @deferred_update_messages, "Recorded previous head for preservation";
return ('deferred', undef);
}
~ianmdlvl / dgit.git / blobdiff