tweak "bundle verify" of a complete history

A bundle that records a complete history without prerequiste is a
useful way to sneakernet the sources of your configuration files
under your home directory, etc.  E.g.

    $ GIT_DIR=/srv/git/homesrc.git git bundle create x.bndl HEAD master

Running "git bundle verify" on such a "complete" bundle, however,
gives somewhat a funny output.

    $ git bundle verify x.bndl
    The bundle contains 2 refs
    b2611f37ebc7ed6435a72d77fbc5f8b48a7d7146 HEAD
    b2611f37ebc7ed6435a72d77fbc5f8b48a7d7146 refs/heads/master
    The bundle requires these 0 refs
    x.bndl is okay

Reword "requires these 0 refs" to say "The bundle records a complete
history" instead.

Signed-off-by: Junio C Hamano <gitster@pobox.com>

bundle.c

@@ -188,12 +188,16 @@ int verify_bundle(struct bundle_header *header, int verbose)
 			     r->nr),
 			  r->nr);
 		list_refs(r, 0, NULL);
-		r = &header->prerequisites;
-		printf_ln(Q_("The bundle requires this ref",
-			     "The bundle requires these %d refs",
-			     r->nr),
-			  r->nr);
-		list_refs(r, 0, NULL);
+		if (!r->nr) {
+			printf_ln(_("The bundle records a complete history."));
+		} else {
+			r = &header->prerequisites;
+			printf_ln(Q_("The bundle requires this ref",
+				     "The bundle requires these %d refs",
+				     r->nr),
+				  r->nr);
+			list_refs(r, 0, NULL);
+		}
 	}
 	return ret;
 }