How-to diff across a renaming?

[Marcos Cruz]

Is it possible to compare two versions of a file which has been renamed,
across the revision in which it was renamed, and with any diff tool?

Say I have these revisions:

- R0: OLDFILE exists
- R1: hg mv OLDFILE NEWFILE # and then also modify NEWFILE
- R2: NEWFILE exists

In order to compare the changes across the renaming I tried the
following (with `diff` and other tools):

  hg diff --from R0 --to R2 NEWFILE # displays only NEWFILE, as added
  hg diff --from R0 --to R2 OLDFILE # displays only OLDFILE, as deleted
  hg diff --from R2 --to R0 NEWFILE # displays only NEWFILE, as deleted
  hg diff --from R2 --to R0 OLDFILE # displays only OLDFILE, as added

Then I noticed this example in `hp help diff`, which reads a cryptic
"with rename info":

________
- compare two historical versions of a directory, with rename info:

    hg diff --git --from 1.0 --to 1.2 lib/
________

And tried this, which works fine (it displays the changes from OLDFILE
to NEWFILE):

  hg diff --git --from R0 --to R2 NEWFILE

But it seems there's no way to do it with other diff tools, right? `hg
help diffs` and `hg help.config.diff` say nothing about this.

Thanks.

-- 
Marcos Cruz
http://programandala.net