dgit: Prevent pushing old versions

Bail out if the changelog version we are uploading is not strictly
newer than the .dsc version in the archive.

Closes: #1050711
Signed-off-by: Ian Jackson <ijackson@chiark.greenend.org.uk>

1 files changed, 11 insertions, 0 deletions

diff --git a/dgit b/dgit
index 43f4aa2..f2a1ce9 100755
--- a/dgit
+++ b/dgit
@@ -4680,6 +4680,7 @@ END
 	git_fetch_us();
     }
     my $archive_hash = fetch_from_archive();
+    my $archive_dsc = $dsc;
     if (!$archive_hash) {
 	$new_package or
 	    fail __ "package appears to be new in this suite;".
@@ -4737,6 +4738,16 @@ END
 
     my $upstreamversion = upstreamversion $clogp->{Version};
 
+    if (defined $archive_dsc && 
+	version_compare($archive_dsc->{Version}, $cversion) >= 0 &&
+	!forceing [qw(uploading-old-version)]) {
+      fail f_ <<'END', $archive_dsc->{Version}, $csuite, $cversion;
+You seem to be trying to push an old version.
+Version current in archive:       %s (in suite %s)
+Version you are trying to upload: %s
+END
+    }
+
     if (madformat_wantfixup($format)) {
 	# user might have not used dgit build, so maybe do this now:
 	if (do_split_brain()) {