+
+ my @mode_changes;
+ my $raw = cmdoutput @git,
+ qw(diff --no-renames -z -r --raw), $tree, $dgithead;
+ my $changed;
+ foreach (split /\0/, $raw) {
+ if (defined $changed) {
+ push @mode_changes, "$changed: $_\n" if $changed;
+ $changed = undef;
+ next;
+ } elsif (m/^:0+ 0+ /) {
+ $changed = '';
+ } elsif (m/^:(?:10*)?(\d+) (?:10*)?(\d+) /) {
+ $changed = "Mode change from $1 to $2"
+ } else {
+ die "$_ ?";
+ }
+ }
+ if (@mode_changes) {
+ fail <<END.(join '', @mode_changes).<<END;
+HEAD specifies a different tree to $dscfn:
+$diffs
+END
+There is a problem with your source tree (see dgit(7) for some hints).
+To see a full diff, run git diff $tree $referent
+END
+ }
+
+ fail <<END;