[darcs-devel] unstable doesn't get consistently with 1.0.3

[David Roundy]

On Thu, Aug 11, 2005 at 12:10:17AM +0100, Ian Lynagh wrote:
> 
> Hi all,
> 
>     darcs get http://cvs.haskell.org/darcs/cabal
> 
> is behaving differently with 1.0.3 and unstable (i.e. _darcs/current is
> different depending on which you use). This probably means there is
> some detail wrong with the more efficient apply code, but unfortunately
> I won't have time to look at it quite yet.

Argh.  That's an annoying bug.  I've got a fix (which I'll send in soon)
that fixes the problems that show up in the cabal repository, but I think
there may still be problems with patches that delete the end of a file and
then replace with a new end (in separate hunks).

A different fix (and perhaps both simpler and more correct) might be to
coalesce before applying, which would eliminate overlapping or touching
hunks.

> Although one option would be to revert to the old code and ignore the
> inefficiency until the new hunk format comes, we have to solve this
> problem anyway in order to convert old hunks to new hunks, so I don't
> think this would really gain us much.

I'd definitely prefer to fix the new code.

> (also useful would be tests of getting repos with various corner case
> patches in, e.g. creating empty files, files with a single '\n',
> emptying files, removing all but a newline from files, etc. The
> interesting files to switch back and forth between are probably
> "" "\n" "foo" "foo\n" "foo\nbar" "foo\nbar\n" "bar\nfoo" "bar\nfoo\n").

Yeah, it would be great if someone were to code up some test cases.  The
trick is that we'd need to be sure to pull rather than getting the patches,
since local gets won't actually use apply.  We could alternately use check
to test for this behavior.
-- 
David Roundy
http://www.darcs.net