git-debrebase: merge: Get debian/ parts of new patch queue right

We want the newly generated delta queue commits to have the $newbase's
debian/.  Previously we let read_tree_upstream save and restore
debian/, but the contents of debian/ in the index are not right:
they're the result of the git merge, which is whatever is left over
from earlier.

Signed-off-by: Ian Jackson <ijackson@chiark.greenend.org.uk>

1 files changed, 23 insertions, 10 deletions

diff --git a/git-debrebase b/git-debrebase
index 4f9a9bb..60ea976 100755
--- a/git-debrebase
+++ b/git-debrebase
@@ -522,7 +522,7 @@ sub merge_series ($$;@) {
 	foreach my $c (grep /./, split /\n/, cmdoutput @lcmd) {
 	    my $commit = git_cat_file $c, 'commit';
 	    printdebug "merge_series series ok, building $c\n";
-	    read_tree_upstream $c;
+	    read_tree_upstream $c, 0, $newbase;
 	    my $tree = cmdoutput @git, qw(write-tree);
 	    $commit =~ s{^parent (\S+)$}{parent $build}m or confess;
 	    $commit =~ s{^tree (\S+)$}{tree $tree}m      or confess;
@@ -1332,16 +1332,29 @@ sub walk ($;$$$) {
 		    $cl->{MergeInterchangeBaseInfo},
 		    @{ $cl->{Parents} };
 		$last_anchor = $cl->{MergeBestAnchor};
-		my $check_differs = get_differs $build, $cl->{CommitId};
+
+		# 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 should be in MergeCreateMergedBreakwaters
-		# output.  Upstream changes are exactly the result
-		# of merge_series.  So the only difference should
-		# be potential laundry results.
-		$nomerge->(sprintf
-                    "merge misresolved: tree is not the same (%s %s d.%#x)",
-			   $cl->{CommitId}, $build, $check_differs)
-		    if $check_differs & ~D_PAT_ADD;
+		# 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 {