Merge branch 'cb/clear-quarantine-early-on-all-ref-update-errors'

"receive-pack" checks if it will do any ref updates (various
conditions could reject a push) before received objects are taken
out of the temporary directory used for quarantine purposes, so
that a push that is known-to-fail will not leave crufts that a
future "gc" needs to clean up.

* cb/clear-quarantine-early-on-all-ref-update-errors:
  receive-pack: purge temporary data if no command is ready to run

builtin/receive-pack.c

@@ -1961,6 +1961,15 @@ static void execute_commands(struct command *commands,
 		return;
 	}
 
+	/*
+	 * If there is no command ready to run, should return directly to destroy
+	 * temporary data in the quarantine area.
+	 */
+	for (cmd = commands; cmd && cmd->error_string; cmd = cmd->next)
+		; /* nothing */
+	if (!cmd)
+		return;
+
 	/*
 	 * Now we'll start writing out refs, which means the objects need
 	 * to be in their final positions so that other processes can see them.