Submodule merges are, in general, similar to other merges based on oid
three-way-merge. When a conflict happens, however, Git has two special
cases (introduced in 68d03e4a6e44) on handling the conflict before
yielding it to the user. From the merge-ort and merge-recursive sources:
- "Case #1: a is contained in b or vice versa": both strategies try to
perform a fast-forward in the submodules if the commit referred by the
conflicted submodule is descendant of another;
- "Case #2: There are one or more merges that contain a and b in the
submodule. If there is only one, then present it as a suggestion to the
user, but leave it marked unmerged so the user needs to confirm the
resolution."
Add a small paragraph on merge-strategies.adoc describing this behavior.
Helped-by: Elijah Newren <newren@xxxxxxxxx>
Signed-off-by: Lucas Seiki Oshiro <lucasseikioshiro@xxxxxxxxx>
---
This v2 changes the documentation text to a clearer explanation (as
suggested in the v1 review), and changes its location to
merge-strategies.adoc instead of git-merge.adoc.
This content is duplicated as this works for both `ort` and `recursive`
strategies.
Documentation/merge-strategies.adoc | 15 ++++++++++++++
1 file changed, 14 insertions(+)
diff --git a/Documentation/merge-strategies.adoc b/Documentation/merge-strategies.adoc
index 5fc54ec060..a7fca249e2 100644
--- a/Documentation/merge-strategies.adoc
+++ b/Documentation/merge-strategies.adoc
@@ -21,6 +21,13 @@ ort::
("Ostensibly Recursive's Twin") and came from the fact that it
was written as a replacement for the previous default
algorithm, `recursive`.
+
+ In the case where the path is a submodule, if the submodule commit
+ used on one side of the merge is a descendant of the submodule
+ commit used on the other side of the merge, Git attempts to
+ fast-forward to the descendant. Otherwise, Git will treat this case
+ as a conflict, suggesting as a resolution a submodule commit that
+ is descendant of the conflicting ones, if one exists.
+
The 'ort' strategy can take the following options:
@@ -95,6 +102,13 @@ recursive::
renames. It does not make use of detected copies. This was
the default strategy for resolving two heads from Git v0.99.9k
until v2.33.0.
+
+ In the case where the path is a submodule, if the submodule commit
+ used on one side of the merge is a descendant of the submodule
+ commit used on the other side of the merge, Git attempts to
+ fast-forward to the descendant. Otherwise, Git will treat this case
+ as a conflict, suggesting as a resolution a submodule commit that
+ is descendant of the conflicting ones, if one exists.
+
The 'recursive' strategy takes the same options as 'ort'. However,
there are three additional options that 'ort' ignores (not documented
--
2.39.5 (Apple Git-154)
