difftools trouble with CR LF on Windows

[Matt McClure]

> When WinMerge displays the files after a command like:
> 
> bzr diff --using WinMerge.exe Shizzle.cpp
> 
> the "before" side of the diff has lines that end in CRCRLF.

Another data point: recursively diffing entire directories, as with:

bzr diff --using WinMerge.exe

makes bzr/difftools/WinMerge do The Right Thing.  How can they be made
not to insert the extra CR with the single file style bzr diff?

Thanks,
Matt