Subject: Re: bug#6326: 23.1.95; `vc-diff' sometimes reports wrong diff status

From: Dan Nicolaescu <[email-masked]>
Date: Wed, 02 Jun 2010 05:42:27 -0400

Markus Triska <[email-masked]> writes:

> When I open (in emacs -Q) a file under "git" version control and:
>
>    1) view its log with: C-x v l
>    2) open any previous revision, for example: n n n f
>    3) save the previous revision under a different name:
>       C-x C-w difrev.txt RET
>    4) on difrev.txt, run `vc-diff' with: C-x v =
>
> it unexpectedly says: "No changes between working revision and
> workfile". It SHOULD say that the file is NOT under version control.
> Also other operations like C-x v l should say this but currently don't
> (C-x v l instead unexpectedly displays the log of the original file).

This because `vc-parent-file' still points to the original file. 
Maybe `vc-file-clearprops' (called from `write-file') should also reset `vc-parent-file'.