git rerere and diff3

hi there,

i have noticed that merge.conflictstyle has an impact on the rerere resolution. looking briefly at the source code, it seems that git tries to discard the common ancestor diff3 bits, but what I am seeing is that if i do the following then it fails:

1. from a clean rr-cache state, with merge.conflictsytle=diff3, git
merge <branch with conflict>, resolve the conflicts, then commit
2. undo the previous merge, remove merge.conflictstyle=diff3 (disable
diff3) and merge the *same* branch, then rerere won't fix the
conflicts

Is that the expected behavior? I am not familiar with git code, but browsing rerere.c makes me think that it should have worked..

Of course, if I merge the same branch without modifying merge.conflictstyle, then the merge conflicts are properly resolved by rerere.

thanks!