X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=dgit.git;a=blobdiff_plain;f=git-debrebase;h=6d51a90ba7c1cd50c7d6d3062a823acb76d24732;hp=c463f4ace5e2c5ba319d815291b922ce0780e540;hb=0d821f5b266626e266c59522017f6d9e714d89c3;hpb=892352e386b2908574d660df3ee778171f59995b

diff --git a/git-debrebase b/git-debrebase
index c463f4ac..6d51a90b 100755
--- a/git-debrebase
+++ b/git-debrebase
@@ -263,11 +263,15 @@ sub read_tree_debian ($) {
     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;
 };
 
@@ -391,6 +395,8 @@ sub merge_series ($$;@) {
 	foreach my $q ($base_q, reverse @input_qs) {
 	    my $s = $q->{MR}{S};
 	    gbp_pq_export "p-$s", $q->{SeriesBase}, $q->{SeriesTip};
+	    # xxx avoid trying to merge debian/ again here, by
+	    # always using debian/ from newbase
 	    if (open S, $seriesfile) {
 		my @earlier;
 		while (my $patch = <S>) {
@@ -518,7 +524,7 @@ sub merge_series ($$;@) {
 	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;
@@ -529,6 +535,13 @@ sub merge_series ($$;@) {
 	}
 	$result = $build;
 	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);
+	printdebug sprintf "merge_series done debug=%s\n",
+	    git_rev_parse 'HEAD';
     };
     printdebug "merge_series returns $result\n";
     return $result;
@@ -810,8 +823,23 @@ sub classify ($) {
     return $classify->("VanillaMerge");
 }
 
-sub keycommits ($;$$$$) {
-    my ($head, $furniture, $unclean, $trouble, $fatal) = @_;
+sub keycommits ($;$$$$$);
+
+sub mergedbreakwaters_anchor ($) {
+    my ($cl) = @_;
+    my $best_anchor;
+    foreach my $p (@{ $cl->{Parents} }) {
+	my ($panchor, $pbw) = keycommits $p->{CommitId},
+	    undef,undef,undef,undef, 1;
+	$best_anchor = $panchor
+	    if !defined $best_anchor
+	    or is_fast_fwd $best_anchor, $panchor;
+    }
+    return $best_anchor;
+}
+
+sub keycommits ($;$$$$$) {
+    my ($head, $furniture, $unclean, $trouble, $fatal, $claimed_bw) = @_;
     # => ($anchor, $breakwater)
 
     # $unclean->("unclean-$tagsfx", $msg, $cl)
@@ -827,6 +855,8 @@ sub keycommits ($;$$$$) {
     # $fatal is for unprocessable commits, and should normally cause
     #    a failure.  If ignored, agaion, (undef, undef) is returned.
     #
+    # If $claimed_bw, this is supposed to be a breakwater commit.
+    #
     # If a callback is undef, fail is called instead.
     # If a callback is defined but false, the situation is ignored.
     # Callbacks may say:
@@ -834,6 +864,7 @@ sub keycommits ($;$$$$) {
     # if the answer is no longer wanted.
 
     my ($anchor, $breakwater);
+    $breakwater = $head if $claimed_bw;
     my $clogonly;
     my $cl;
     my $found_pm;
@@ -846,6 +877,13 @@ sub keycommits ($;$$$$) {
 	return unless $cb;
 	$cb->("unclean-$tagsfx", $why, $cl, $mainwhy);
     };
+    my $found_anchor = sub {
+	($anchor) = @_;
+	$breakwater //= $clogonly;
+	$breakwater //= $head;
+	no warnings qw(exiting);
+	last;
+    };
     for (;;) {
 	$cl = classify $head;
 	my $ty = $cl->{Type};
@@ -859,10 +897,7 @@ sub keycommits ($;$$$$) {
 	} elsif ($ty eq 'Anchor' or
 		 $ty eq 'TreatAsAnchor' or
 		 $ty eq 'BreakwaterStart') {
-	    $anchor = $head;
-	    $breakwater //= $clogonly;
-	    $breakwater //= $head;
-	    last;
+	    $found_anchor->($head);
 	} elsif ($ty eq 'Upstream') {
 	    $x->($unclean, 'ordering',
  "packaging change ($breakwater) follows upstream change"," (eg $head)")
@@ -894,6 +929,8 @@ sub keycommits ($;$$$$) {
 	    $x->($trouble, 'vanillamerge',
 		 "found vanilla merge"," ($head)");
 	    return (undef,undef);
+	} elsif ($ty eq 'MergedBreakwaters') {
+	    $found_anchor->(mergedbreakwaters_anchor $cl);
 	} else {
 	    $x->($fatal, 'unprocessable',
 		 "found unprocessable commit, cannot cope: $cl->{Why}",
@@ -1082,8 +1119,16 @@ sub walk ($;$$$) {
 	    }
 	    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!
+	    # 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 $best_anchor;
 	    # We expect to find a dominating anchor amongst the
@@ -1207,7 +1252,8 @@ sub walk ($;$$$) {
 	    push @brw_cl, {
                 %$cl,
                 SpecialMethod => 'MergeCreateMergedBreakwaters',
-                $xmsg->('construct merged breakwater from vanilla merge'),
+                $xmsg->('constructed from vanilla merge',
+			' merged-breakwater'),
             };
 	    push @upp_cl, {
                 %$cl,
@@ -1232,6 +1278,11 @@ sub walk ($;$$$) {
 
     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 $committer_authline = calculate_committer_authline();
@@ -1259,7 +1310,7 @@ sub walk ($;$$$) {
 	    if ($method eq 'Debian') {
 		read_tree_debian($cltree);
 	    } elsif ($method eq 'Upstream') {
-		read_tree_upstream($cltree);
+		$read_tree_upstream->($cltree);
 	    } elsif ($method eq 'StartRewrite') {
 		$rewriting = 1;
 		next;
@@ -1272,13 +1323,13 @@ sub walk ($;$$$) {
  		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') {
@@ -1288,7 +1339,29 @@ sub walk ($;$$$) {
 		    $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 {