case of a merge conflict.
--ff::
- When the merge resolves as a fast-forward, only update the branch
- pointer, without creating a merge commit. This is the default
- behavior.
-
--no-ff::
- Create a merge commit even when the merge resolves as a
- fast-forward. This is the default behaviour when merging an
- annotated (and possibly signed) tag that is not stored in
- its natural place in 'refs/tags/' hierarchy.
-
--ff-only::
- Refuse to merge and exit with a non-zero status unless the
- current `HEAD` is already up to date or the merge can be
- resolved as a fast-forward.
+ Specifies how a merge is handled when the merged-in history is
+ already a descendant of the current history. `--ff` is the
+ default unless merging an annotated (and possibly signed) tag
+ that is not stored in its natural place in the `refs/tags/`
+ hierarchy, in which case `--no-ff` is assumed.
++
+With `--ff`, when possible resolve the merge as a fast-forward (only
+update the branch pointer to match the merged branch; do not create a
+merge commit). When not possible (when the merged-in history is not a
+descendant of the current history), create a merge commit.
++
+With `--no-ff`, create a merge commit in all cases, even when the merge
+could instead be resolved as a fast-forward.
++
+With `--ff-only`, resolve the merge as a fast-forward when possible.
+When not possible, refuse to merge and exit with a non-zero status.
-S[<keyid>]::
--gpg-sign[=<keyid>]::