[backend] drop the inode number from the deltaid hash, it breaks if t…

…he tree is copied

The inode is good for internal stuff, but bad for deltas, as deltas
get published and a redone delta is newly signed and thus end up
different than the old delta.
Copy over the old delta if we have one to ease migration.

src/backend/bs_sched

@@ -1130,7 +1130,19 @@ sub makedeltas {
 	  my $aextrep = $oldbins{$aprp};
 	  my @s = stat("$aextrep/$binarch/$obin");
 	  next unless @s;
-	  my $deltaid = Digest::MD5::md5_hex("$packid/$bin/$aprp/$obin/$s[9]/$s[7]/$s[1]");
+	  # 2013-09-05 mls: dropped $s[1]
+	  my $deltaid = Digest::MD5::md5_hex("$packid/$bin/$aprp/$obin/$s[9]/$s[7]");
+	  if (!$ddir{$deltaid}) {
+	    # see if we know it under the old id
+	    my $olddeltaid = Digest::MD5::md5_hex("$packid/$bin/$aprp/$obin/$s[9]/$s[7]/$s[1]");
+	    if ($ddir{$olddeltaid}) {
+	      # yes, link it over
+	      unlink("$ddir/$deltaid");
+	      unlink("$ddir/$deltaid.dseq");
+	      link("$ddir/$olddeltaid", "$ddir/$deltaid");
+	      link("$ddir/$olddeltaid.dseq", "$ddir/$deltaid.dseq");
+	    }
+	  }
 	  $deltaids{$deltaid} = 1;
           if ($ddir{$deltaid}) {
 	    next unless $ddir{"$deltaid.dseq"};		# delta was too big