`-X patience` vs `-X diff-algorithm=patience` with `git merge-recursive`

Question

What is the difference between git merge -s recursive -X patience other-branch git merge -s recursive -X diff-algorithm=patience other-branch

Also do either of git merge -s recursive -X patience -X diff-algorithm=patience other-branch git merge -s recursive -X patience -X diff-algorithm=histogram other-branch mean anything. If so, what?

Answer 1

What is the difference between

git merge -s recursive -X patience other-branch
git merge -s recursive -X diff-algorithm=patience other-branch

None. -X patience is an old name for -X diff-algorithm=patience, dating back to when there was only one alternative. You can, currently, spell the histogram algorithm with -X histogram as well. The only one requiring -X diff-algorithm= is minimal.

Also do either of

git merge -s recursive -X patience -X diff-algorithm=patience other-branch
git merge -s recursive -X patience -X diff-algorithm=histogram other-branch

mean anything. If so, what?

The last algorithm chosen on the command line overrides any previous ones on the command line, so these both have the effect of ignoring the first -X option.

(Note that -s recursive is the default strategy for merge when merging two commits, so this is redundant as well. It doesn't hurt, it just makes no difference.)