[PATCH] don't allow tagging the null revision (issue1915)

[Matt Mackall]

On Thu, 2012-07-26 at 14:21 -0700, Brad Hall wrote:
> # HG changeset patch
> # User Brad Hall <bhall at fb.com>
> # Date 1338940813 25200
> # Node ID da78ad7f8183569ebd154b448e2b49a43583532a
> # Parent  cd7db8e05c657fb08b51903fa2ef8c2246de1c4b
> don't allow tagging the null revision (issue1915)

Queued for stable after correcting the summary format, thanks.

* first line of commit message is of the form "subsystem: uncapitalized,
no trailing period"

-- 
Mathematics is the supreme nostalgia of our time.