Re: your mail

[Davide Libenzi <davidel@xmailserver.org>]

On Tue, 21 Nov 2006, Johannes Schindelin wrote:

> [PATCH] xdiff: add xdl_merge()
> 
> This new function implements the functionality of RCS merge, but
> in-memory. It returns < 0 on error, otherwise the number of conflicts.
> 
> Finding the conflicting lines can be a very expensive task. You can
> control the eagerness of this algorithm:
> 
> - a level value of 0 means that all overlapping changes are treated
>   as conflicts,
> - a value of 1 means that if the overlapping changes are identical,
>   it is not treated as a conflict.
> - If you set level to 2, overlapping changes will be analyzed, so that
>   almost identical changes will not result in huge conflicts. Rather,
>   only the conflicting lines will be shown inside conflict markers.
> 
> With each increasing level, the algorithm gets slower, but more accurate.
> Note that the code for level 2 depends on the simple definition of
> mmfile_t specific to git, and therefore it will be harder to port that
> to LibXDiff.

Johannes, at the moment I'm chased by a huge storm of never ending emails, 
so I won't be able to follow up this one soon. A smart 3-way merge is in 
my plans for LibXDiff though.
There is quite some nice code around, that does pretty smart tricks and 
goes down to resolve sub-hunk non-trivial conflicts. You may want to take 
a look at that code too.



- Davide