git-debrebase: Properly reject bare dgit dsc imports

A bare dgit dsc import is not a legal gdr branch, because the main
merge contains debian/patches/.  So it cannot be processed without
conversion.

Previously an attempt to launder such a branch would crash with a
stack trace, although keycommits would falsely claim it was OK

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

1 files changed, 18 insertions, 10 deletions

diff --git a/git-debrebase b/git-debrebase
index 13c320e..a2a14ca 100755
--- a/git-debrebase
+++ b/git-debrebase
@@ -595,6 +595,7 @@ sub keycommits ($;$$$$) {
     my ($anchor, $breakwater);
     my $clogonly;
     my $cl;
+    my $found_pm;
     $fatal //= sub { fail $_[1]; };
     my $x = sub {
 	my ($cb, $tagsfx, $mainwhy, $xwhy) = @_;
@@ -634,12 +635,20 @@ sub keycommits ($;$$$$) {
 	    $breakwater = undef;
 	} elsif ($ty eq 'Pseudomerge' or
 		 $ty eq 'AddPatches') {
+	    my $found_pm = 1;
 	    $x->($furniture, (lc $ty),
 		 "found interchange bureaucracy commit ($ty)"," ($head)");
 	} elsif ($ty eq 'DgitImportUnpatched') {
-	    $x->($trouble, 'dgitimport',
-		 "found dgit dsc import ($head)");
-	    return (undef,undef);
+	    if ($found_pm) {
+		$x->($trouble, 'dgitimport',
+		     "found dgit dsc import"," ($head)");
+		return (undef,undef);
+	    } else {
+		$x->($fatal, 'unprocessable',
+		     "found bare dgit dsc import with no prior history",
+		     " ($head)");
+		return (undef,undef);
+	    }
 	} else {
 	    $x->($fatal, 'unprocessable',
 		 "found unprocessable commit, cannot cope: $cl->{Why}",
@@ -814,13 +823,12 @@ sub walk ($;$$) {
 		next;
 	    } else {
 		# Everything is from this import.  This kind of import
-		# is already in valid breakwater format, with the
-		# patches as commits.
-		printf $report " NoPM" if $report;
-		# last thing we processed will have been the first patch,
-		# if there is one; which is fine, so no need to rewrite
-		# on account of this import
-		$build_start->("ImportOrigin", $cur);
+		# is already nearly in valid breakwater format, with the
+		# patches as commits.  Unfortunately it contains
+		# debian/patches/.
+		printdebug "*** WALK BOMB bare dgit import\n";
+		$cl->{Why} = "bare dgit dsc import";
+		return $bomb->();
 	    }
 	    die "$ty ?";
         } else {