[Gnu-arch-users] Re: practical diff-mode.el question

[Stefan Monnier]

> diff-mode.el is a godsend, especially the hunk splitting capability.

How sweet!  Can you do that again?

> Is there a way to say "show me why this doesn't apply", i.e., a
> difference of the expected regions for modification and what is
> actually there?  It doesn't appear there's anything native in
> diff-mode.el for this, but maybe someone has conjured up a trick or
> hack for this.  It seems obvious enough that it's hard to believe
> something like this doesn't already exist, or maybe I am missing an
> obvious way to achieve it.

Sadly, I don't know of any such trick with diff-mode, although I have wished
for one many a times and have wondered how I could go about implementing it.
What you can try is to use `wiggle': it is more permissive of cosmetic
changes, so it may be able to apply the hunk, and if it isn't able then
it'll turn it into diff3 markers at which point smerge-mode can be used to
diff the expected and the actual text to see what's conflicting.

I've been meaning to add support for `wiggle' to diff-mode, but haven't
gotten around to it yet, partly because wiggle makes it more difficult than
it needs to be.


        Stefan