MERGE STRATEGIES
----------------
+The merge mechanism ('git-merge' and 'git-pull' commands) allows the
+backend 'merge strategies' to be chosen with `-s` option. Some strategies
+can also take their own options, which can be passed by giving `-X<option>`
+arguments to 'git-merge' and/or 'git-pull'.
+
resolve::
This can only resolve two heads (i.e. the current branch
- and another branch you pulled from) using 3-way merge
+ and another branch you pulled from) using a 3-way merge
algorithm. It tries to carefully detect criss-cross
merge ambiguities and is considered generally safe and
- fast. This is the default merge strategy when pulling
- one branch.
+ fast.
recursive::
- This can only resolve two heads using 3-way merge
- algorithm. When there are more than one common
- ancestors that can be used for 3-way merge, it creates a
- merged tree of the common ancestores and uses that as
+ This can only resolve two heads using a 3-way merge
+ algorithm. When there is more than one common
+ ancestor that can be used for 3-way merge, it creates a
+ merged tree of the common ancestors and uses that as
the reference tree for the 3-way merge. This has been
reported to result in fewer merge conflicts without
causing mis-merges by tests done on actual merge commits
taken from Linux 2.6 kernel development history.
Additionally this can detect and handle merges involving
- renames.
+ renames. This is the default merge strategy when
+ pulling or merging one branch.
++
+The 'recursive' strategy can take the following options:
+
+ours;;
+ This option forces conflicting hunks to be auto-resolved cleanly by
+ favoring 'our' version. Changes from the other tree that do not
+ conflict with our side are reflected to the merge result.
++
+This should not be confused with the 'ours' merge strategy, which does not
+even look at what the other tree contains at all. It discards everything
+the other tree did, declaring 'our' history contains all that happened in it.
+
+theirs;;
+ This is opposite of 'ours'.
+
+subtree[=path];;
+ This option is a more advanced form of 'subtree' strategy, where
+ the strategy makes a guess on how two trees must be shifted to
+ match with each other when merging. Instead, the specified path
+ is prefixed (or stripped from the beginning) to make the shape of
+ two trees to match.
octopus::
- This resolves more than two-head case, but refuses to do
- complex merge that needs manual resolution. It is
+ This resolves cases with more than two heads, but refuses to do
+ a complex merge that needs manual resolution. It is
primarily meant to be used for bundling topic branch
heads together. This is the default merge strategy when
- pulling more than one branch.
+ pulling or merging more than one branch.
ours::
- This resolves any number of heads, but the result of the
- merge is always the current branch head. It is meant to
+ This resolves any number of heads, but the resulting tree of the
+ merge is always that of the current branch head, effectively
+ ignoring all changes from all other branches. It is meant to
be used to supersede old development history of side
- branches.
+ branches. Note that this is different from the -Xours option to
+ the 'recursive' merge strategy.
+
+subtree::
+ This is a modified recursive strategy. When merging trees A and
+ B, if B corresponds to a subtree of A, B is first adjusted to
+ match the tree structure of A, instead of reading the trees at
+ the same level. This adjustment is also done to the common
+ ancestor tree.