our $us = qw(git-debrebase);
+our $wrecknoteprefix = 'refs/debrebase-wreckage';
+
$|=1;
sub badusage ($) {
die $@ if $@;
}
-sub fresh_workarea () {
- $workarea = fresh_playground "$playprefix/work";
+sub fresh_workarea (;$) {
+ my ($subdir) = @_;
+ $subdir //= 'work';
+ $workarea = fresh_playground "$playprefix/$subdir";
in_workarea sub { playtree_setup };
}
+sub run_ref_updates_now ($$) {
+ my ($mrest, $updates) = @_;
+ # @$updates is a list of lines for git-update-ref, without \ns
+
+ my @upd_cmd = (git_update_ref_cmd "debrebase: $mrest", qw(--stdin));
+ debugcmd '>|', @upd_cmd;
+ open U, "|-", @upd_cmd or die $!;
+ foreach (@$updates) {
+ printdebug ">= ", $_, "\n";
+ print U $_, "\n" or die $!;
+ }
+ printdebug ">\$\n";
+ close U or failedcmd @upd_cmd;
+}
+
our $snags_forced = 0;
our $snags_tripped = 0;
our $snags_summarised = 0;
our @deferred_updates;
our @deferred_update_messages;
+sub merge_wreckage_cleaning ($) {
+ my ($updates) = @_;
+ git_for_each_ref("$wrecknoteprefix/*", sub {
+ my ($objid,$objtype,$fullrefname,$reftail) = @_;
+ push @$updates, "delete $fullrefname";
+ });
+}
+
sub all_snags_summarised () {
$snags_forced + $snags_tripped == $snags_summarised;
}
confess 'dangerous internal error' unless all_snags_summarised();
- my @upd_cmd = (git_update_ref_cmd "debrebase: $mrest", qw(--stdin));
- debugcmd '>|', @upd_cmd;
- open U, "|-", @upd_cmd or die $!;
- foreach (@deferred_updates) {
- printdebug ">= ", $_, "\n";
- print U $_, "\n" or die $!;
- }
- printdebug ">\$\n";
- close U or failedcmd @upd_cmd;
-
+ merge_wreckage_cleaning \@deferred_updates;
+ run_ref_updates_now $mrest, \@deferred_updates;
print $_, "\n" foreach @deferred_update_messages;
@deferred_updates = ();
rm_subdir_cached 'debian/patches';
}
-sub read_tree_upstream ($;$) {
- my ($treeish, $keep_patches) = @_;
- my $save = cmdoutput @git, qw(write-tree --prefix=debian/);
+sub read_tree_upstream ($;$$) {
+ my ($treeish, $keep_patches, $tree_with_debian) = @_;
+ # if $tree_with_debian is supplied, will use that for debian/
+ # otherwise will save and restore it.
+ my $debian =
+ $tree_with_debian ? "$tree_with_debian:debian"
+ : cmdoutput @git, qw(write-tree --prefix=debian/);
runcmd @git, qw(read-tree), $treeish;
- read_tree_subdir 'debian', $save;
+ read_tree_subdir 'debian', $debian;
rm_subdir_cached 'debian/patches' unless $keep_patches;
};
{ local ($!,$?); copy('../gbp-pq-err', \*STDERR); }
failedcmd @gbp_cmd;
}
- runcmd @git, qw(add -f debian/patches);
+ runcmd @git, qw(add -f debian/patches) if stat_exists 'debian/patches';
}
-# xxx allow merge separately from laundering
+# xxx allow merge resolution separately from laundering, before git merge
#
-# xxx docs highlight forbidden things
-# xxx docs list allowable things ?
-# xxx docs explicitly forbid some rebase
+# xxx general gdr docs highlight forbidden things
+# xxx general gdr docs list allowable things ?
+# xxx general gdr docs explicitly forbid some rebase
#
# xxx provide a way for the user to help
# xxx (eg, provide wreckage provide way to continue)
# our own patch identification algorithm?
# this is an alternative strategy
-sub merge_series ($$;@) {
- my ($newbase, $base_q, @input_qs) = @_;
+sub merge_failed ($$;@) {
+ my ($wrecknotes, $emsg, @xmsgs) = @_;
+ my @m;
+ push @m, "Merge resolution failed: $emsg";
+ push @m, @xmsgs;
+
+ changedir $maindir;
+
+ my @updates;
+ merge_wreckage_cleaning \@updates;
+ run_ref_updates_now "merge failed", \@updates;
+
+ @updates = ();
+ keys %$wrecknotes;
+ while (my ($k,$v) = each %$wrecknotes) {
+ push @updates, "create $wrecknoteprefix/$k $v";
+ }
+ run_ref_updates_now "merge failed", \@updates;
+ push @m, "Wreckage left in $wrecknoteprefix/*.";
+
+ push @m, "See git-debrebase(1) section FAILED MERGES for suggestions.";
+
+ # use finish rather than fail, in case we are within an eval
+ # (that can happen inside walk!)
+ print STDERR "\n";
+ print STDERR "$us: $_\n" foreach @m;
+ finish 15;
+}
+
+sub mwrecknote ($$$) {
+ my ($wrecknotes, $reftail, $commitish) = @_;
+ confess unless defined $commitish;
+ printdebug "mwrecknote $reftail $commitish\n";
+ $wrecknotes->{$reftail} = $commitish;
+}
+
+sub merge_attempt_cmd {
+ my $wrecknotes = shift @_;
+ debugcmd '+', @_;
+ $!=0; $?=-1;
+ if (system @_) {
+ merge_failed $wrecknotes,
+ failedcmd_waitstatus(),
+ "failed command: @_";
+ }
+}
+
+sub merge_series ($$$;@) {
+ my ($newbase, $wrecknotes, $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)
my $result;
- local $workarea = fresh_playground "$playprefix/merge";
+ my $mwrecknote = sub { &mwrecknote($wrecknotes, @_); };
+
+ my $attempt_cmd = sub { &merge_attempt_cmd($wrecknotes, @_); };
+
+ local $workarea;
+ fresh_workarea "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};
+ my @earlier;
if (open S, $seriesfile) {
- my @earlier;
while (my $patch = <S>) {
chomp $patch or die $!;
$prereq{$patch} //= {};
" $q->{SeriesTip}]"
];
printdebug "merge_series pec $pec ";
- runcmd @git, qw(rm -q --cached), $seriesfile;
+ runcmd @git, qw(rm -q --ignore-unmatch --cached), $seriesfile;
$pec = make_commit [ $pec ], [
"Drop series file from $s to avoid merge trouble",
"[git-debrebase merge-innards patch-queue prep:".
" $q->{SeriesTip}]"
];
+
+ read_tree_debian $newbase;
+ if (@earlier) {
+ read_tree_subdir 'debian/patches', "$pec:debian/patches";
+ } else {
+ rm_subdir_cached 'debian/patches';
+ }
+ $pec = make_commit [ $pec ], [
+ "Update debian/ (excluding patches) to final to avoid re-merging",
+ "debian/ was already merged and we need to just take that.",
+ "[git-debrebase merge-innards patch-queue packaging:".
+ " $q->{SeriesTip}]"
+ ];
+
printdebug "pec' $pec\n";
runcmd @git, qw(reset -q --hard), $pec;
$q->{MR}{PEC} = $pec;
+ $mwrecknote->("$q->{LeftRight}-patchqueue", $pec);
}
# now, because of reverse, we are on $input_q->{MR}{OQC}
runcmd @git, qw(checkout -q -b merge);
printdebug "merge_series merging...\n";
my @mergecmd = (@git, qw(merge --quiet --no-edit), "p-1");
- debugcmd '+', @mergecmd;
- $!=0; $?=-1;
- if (system @mergecmd) {
- failedcmd @mergecmd;
- }
+
+ $attempt_cmd->(@mergecmd);
printdebug "merge_series merge ok, series...\n";
# We need to construct a new series file
}
runcmd @git, qw(add), $seriesfile;
- runcmd @git, qw(commit --quiet -m), 'Merged series';
+ runcmd @git, qw(commit --quiet -m), 'Merged patch queue form';
+ $mwrecknote->('merged-patchqueue', git_rev_parse 'HEAD');
printdebug "merge_series series gbp pq import\n";
- runcmd qw(gbp pq import);
+
+ merge_attempt_cmd($wrecknotes, 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
foreach my $c (grep /./, split /\n/, cmdoutput @lcmd) {
my $commit = git_cat_file $c, 'commit';
printdebug "merge_series series ok, building $c\n";
- read_tree_upstream $c;
+ read_tree_upstream $c, 0, $newbase;
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;
$build = cmdoutput @git, qw(hash-object -w -t commit ../mcommit);
}
$result = $build;
+ mwrecknote($wrecknotes, 'merged-result', $result);
+
runcmd @git, qw(update-ref refs/heads/result), $result;
+
+ runcmd @git, qw(checkout -q -b debug);
+ runcmd @git, qw(commit --allow-empty -q -m M-INDEX);
+ runcmd @git, qw(add .);
+ runcmd @git, qw(commit --allow-empty -q -m M-WORKTREE);
+ my $mdebug = git_rev_parse 'HEAD';
+ printdebug sprintf "merge_series done debug=%s\n", $mdebug;
+ mwrecknote($wrecknotes, 'merged-debug', $mdebug);
};
printdebug "merge_series returns $result\n";
return $result;
return $classify->("VanillaMerge");
}
-sub keycommits ($;$$$$) {
- my ($head, $furniture, $unclean, $trouble, $fatal) = @_;
+sub keycommits ($;$$$$$);
+
+sub mergedbreakwaters_anchor ($) {
+ my ($cl) = @_;
+ my $best_anchor;
+ foreach my $p (@{ $cl->{Parents} }) {
+ my ($panchor, $pbw) = keycommits $p->{CommitId},
+ undef,undef,undef,undef, 1;
+ $best_anchor = $panchor
+ if !defined $best_anchor
+ or is_fast_fwd $best_anchor, $panchor;
+ fail "inconsistent anchors in merged-breakwaters $p->{CommitId}"
+ unless is_fast_fwd $panchor, $best_anchor;
+ }
+ return $best_anchor;
+}
+
+sub keycommits ($;$$$$$) {
+ my ($head, $furniture, $unclean, $trouble, $fatal, $claimed_bw) = @_;
# => ($anchor, $breakwater)
# $unclean->("unclean-$tagsfx", $msg, $cl)
# $fatal is for unprocessable commits, and should normally cause
# a failure. If ignored, agaion, (undef, undef) is returned.
#
+ # If $claimed_bw, this is supposed to be a breakwater commit.
+ #
# If a callback is undef, fail is called instead.
# If a callback is defined but false, the situation is ignored.
# Callbacks may say:
# if the answer is no longer wanted.
my ($anchor, $breakwater);
+ $breakwater = $head if $claimed_bw;
my $clogonly;
my $cl;
my $found_pm;
return unless $cb;
$cb->("unclean-$tagsfx", $why, $cl, $mainwhy);
};
+ my $found_anchor = sub {
+ ($anchor) = @_;
+ $breakwater //= $clogonly;
+ $breakwater //= $head;
+ no warnings qw(exiting);
+ last;
+ };
for (;;) {
$cl = classify $head;
my $ty = $cl->{Type};
} elsif ($ty eq 'Anchor' or
$ty eq 'TreatAsAnchor' or
$ty eq 'BreakwaterStart') {
- $anchor = $head;
- $breakwater //= $clogonly;
- $breakwater //= $head;
- last;
+ $found_anchor->($head);
} elsif ($ty eq 'Upstream') {
$x->($unclean, 'ordering',
"packaging change ($breakwater) follows upstream change"," (eg $head)")
$x->($trouble, 'vanillamerge',
"found vanilla merge"," ($head)");
return (undef,undef);
+ } elsif ($ty eq 'MergedBreakwaters') {
+ $found_anchor->(mergedbreakwaters_anchor $cl);
} else {
$x->($fatal, 'unprocessable',
"found unprocessable commit, cannot cope: $cl->{Why}",
};
my $nomerge = sub {
- fail "something useful about failed merge attempt @_ xxx".Dumper($cl);
+ my ($emsg) = @_;
+ merge_failed $cl->{MergeWreckNotes}, $emsg;
};
+ my $mwrecknote = sub { &mwrecknote($cl->{MergeWreckNotes}, @_); };
+
my $last_anchor;
for (;;) {
$cl = classify $cur;
+ $cl->{MergeWreckNotes} //= {};
my $ty = $cl->{Type};
my $st = $cl->{SubType};
$prline->("$cl->{CommitId} $cl->{Type}");
return $bomb->();
}
die "$ty ?";
- } elsif ($ty eq 'VanillaMerge' or $ty eq 'MergedBreakwaters') {
- # xxx need to handle ffq if one side was unstitched
- # wait both of them may be!
+ } elsif ($ty eq 'MergedBreakwaters') {
+ $last_anchor = mergedbreakwaters_anchor $cl;
+ $build_start->(' MergedBreakwaters', $cur);
+ last;
+ } elsif ($ty eq 'VanillaMerge') {
+ # User may have merged unstitched branch(es). We will
+ # have now lost what ffq-prev was then (since the later
+ # pseudomerge may introduce further changes). The effect
+ # of resolving such a merge is that we may have to go back
+ # further in history to find a merge base, since the one
+ # which was reachable via ffq-prev is no longer findable.
+ # This is suboptimal, but if it all works we'll have done
+ # the right thing.
+ # xxx we should warn the user in the docs about this
+
my $ok=1;
my $best_anchor;
# We expect to find a dominating anchor amongst the
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};
+ $mwrecknote->('vanilla-merge', $cl->{CommitId});
+
foreach my $p (@$ps) {
$prline->(" VanillaMerge ".$p->{Ix});
$prprdelim->();
$p->{Breakwater} = $p->{SeriesBase} = $pbw;
$p->{Anchor} = $panchor;
+ my $lr = $p->{LeftRight} = (qw(left right))[$p->{Ix}];
+ $mwrecknote->("$lr-input", $p->{CommitId});
+
+ my $mwrecknote_parent = sub {
+ my ($which) = @_;
+ $mwrecknote->("$lr-".(lc $which), $p->{$which});
+ };
+ $mwrecknote_parent->('Laundered');
+ $mwrecknote_parent->('Breakwater');
+ $mwrecknote_parent->('Anchor');
+
$best_anchor = $panchor if
!defined $best_anchor or
is_fast_fwd $best_anchor, $panchor;
" p=$panchor\n";
}
+ $mwrecknote->('result-anchor', $best_anchor);
+
foreach my $p (@$ps) {
$prline->(" VanillaMerge ".$p->{Ix});
if (!is_fast_fwd $p->{Anchor}, $best_anchor) {
- $nomerge->('DivergentAnchor');
+ $nomerge->('divergent anchors');
} elsif ($p->{Anchor} eq $best_anchor) {
print $report " SameAnchor" if $report;
} else {
}
if ($ok && $might_be_in_bw) {
+ # We could rewrite this to contaion the metadata
+ # declaring it to be MergedBreakwaters, but
+ # unnecessarily rewriting a merge seems unhelpful.
$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
# 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");
+
+ @ibs or confess 'internal error, expected anchor at least ?';
+
+ my $ib;
+ my $ibleaf;
+ foreach my $tibix (0..$#ibs) {
+ my $tib = $ibs[$tibix];
+ my $ff = is_fast_fwd $bwb, $tib;
+ my $ok = !$ff ? 'rej' : $ib ? 'extra' : 'ok';
+ my $tibleaf = "interchange-mbcand-$ok-$tibix";
+ $mwrecknote->($tibleaf, $tib);
+ next unless $ff;
+ next if $ib;
+ $ib = $tib;
+ $ibleaf = $tibleaf;
+ }
+
+ $ib or $nomerge->("no suitable interchange merge base");
$prline->(" VanillaMerge Base");
$prprdelim->();
- my ($btip, $bbw, $banchor) =
+ my ($btip, $bbw, $banchor) = eval {
walk $ib, 0, $report, $report_lprefix.' ';
+ };
+ $nomerge->("walking interchange branch merge base ($ibleaf):\n".
+ $@)
+ if length $@;
+
+ $mwrecknote->("mergebase-laundered", $btip);
+ $mwrecknote->("mergebase-breakwater", $bbw);
+ $mwrecknote->("mergebase-anchor", $banchor);
my $ibinfo = { SeriesTip => $btip,
SeriesBase => $bbw,
- Anchor => $banchor };
+ Anchor => $banchor,
+ LeftRight => 'mergebase' };
+
$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})".
(join ' ', map { $_->{Anchor} } @$ps).
")");
-
$cl->{MergeInterchangeBaseInfo} = $ibinfo;
$cl->{MergeBestAnchor} = $best_anchor;
push @brw_cl, {
%$cl,
SpecialMethod => 'MergeCreateMergedBreakwaters',
- $xmsg->('construct merged breakwater from vanilla merge'),
+ $xmsg->('constructed from vanilla merge',
+ ' merged-breakwater'),
};
push @upp_cl, {
%$cl,
my $rewriting = 0;
+ my $read_tree_upstream = sub {
+ my ($treeish) = @_;
+ read_tree_upstream $treeish, 0, $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});
+ $read_tree_upstream->($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,
+ $build, $cl->{MergeWreckNotes},
$cl->{MergeInterchangeBaseInfo},
@{ $cl->{Parents} };
$last_anchor = $cl->{MergeBestAnchor};
- # xxx need to check the tree somehow
+
+ # Check for mismerges:
+ my $check = sub {
+ my ($against, $allow, $what) = @_;
+ my $differs = get_differs $build, $against;
+ $nomerge->(sprintf
+ "merge misresolved: %s are not the same (%s %s d.%#x)",
+ $what, $against, $build, $differs)
+ if $differs & ~($allow | D_PAT_ADD);
+ };
+
+ # Breakwater changes which were in each side of the
+ # merge will have been incorporated into the
+ # MergeCreateMergedBreakwaters output. Because the
+ # upstream series was rebased onto the new breakwater,
+ # so should all of the packaging changes which were in
+ # the input.
+ $check->($input, D_UPS, 'debian files');
+
+ # Upstream files are merge_series, which ought to
+ # have been identical to the original merge.
+ $check->($cl->{CommitId}, DS_DEB, 'upstream files');
+
print "Merge resolution successful.\n";
next;
} else {
~ianmdlvl / dgit.git / blobdiff