how do I preview a patch file from bzr send, e.g.using diff --using meld

[David Ingamells]

Suppose I have a branch in which I have made some updates and commits. I 
am now ready to generate a patch file using "bzr send" so that my 
changes can be merged back into the central repository.

How do I preview(e.g. using meld) what I will be sending?

I can find nothing in the -r options that duplicates the comparisons 
that send must make. I know that I can just make the patch file and view 
it with an editor, but that is not the same as being able to use "diff 
--using meld".

Second, suppose that I have received such a patch file and want to 
review the changes before I merge them into a central repository. Is 
there any way to examine a patch file using, e.g. diff --using meld. The 
patch file is described in the bzr documentation as being like a mini 
branch, but only bzr merge seems to recognise it. "bzr merge --preview" 
does not seem to have the "--using merge" option of diff, instead it 
seems to just be a cat of the first part of the patch file.

I am aware that I could apply the patch to a branch and diff on that, 
but given that it takes 45 minutes (yes! with bzr 1.2 too) to branch 
from one of our repositories, that is not an action to undertake lightly.

finally none of the diff facilities  report the details of "attributes 
changed" they only go so far as

=== modified file '<file name>'* (properties changed)*

How can I see what properties have changed?

Thanks in advance
David.