Re: [PATCH] rerere: fix for merge.conflictstyle

Jeff King [off-list ref] writes:

I could not reproduce the problem with a trivial case, and rerere
specifically tries to handle the differences between "merge" and "diff3"
styles by throwing away the base content between "|" and "=" lines.
However, I wonder if it could still miss a match in some cases because
the "merge" style uses XDL_MERGE_ZEALOUS, whereas diff3 bumps it
down to XDL_MERGE_EAGER, which could lead to a slightly different
preimage.

If so, I think this points to a slightly more pervasive problem in
"rerere", then: data recorded under one merge level might not be usable
later (whether for "rerere forget" or for actually applying a
resolution).
...

So given all of the "hopefully rare" statements above and the complexity
of the complete solution, it's probably not worth pursuing. In which
case your patch seems like the best we can do. At least it covers the
more common case when you have set merge.conflictstyle but _didn't_
change it since the postimage was recorded.

Thanks for a fix, Felipe, and thanks for a more detailed discussion,
Peff.  I think I saw the exact same symptom in "forget" the other
day, but was too busy to pursue it at that moment.