问题
Our project uses a git submodule to pin one of our library dependencies.
We regularly rebase the submodule to follow upstream changes, and we also have a set of commits on top of it that we cannot easily upstream.
When somebody rebases the submodule, I only see this in the git diff of the parent repo:
--- a/mysubmodule
+++ b/mysubmodule
@@ -1 +1 @@
-Subproject commit abc12345abc12345abc12345abcd12345abc1234
+Subproject commit efg67890efg67890efg67890efg67890efg67890
That is not very useful. When I git diff these commits in the submodule, I get a lot of output, including all of the upstream changes, with our commits on top buried in between. I cannot easily judge whether some of the conflict resolution performed on our own commits introduced some mistakes.
How can I effectively code-review the changes to the submodule?
回答1:
Use git range-diff. It was designed for exactly this purpose, to review commit ranges.
If your parent commit repo has:
-Subproject commit abc123
+Subproject commit efg678
then cd into your submodule and run (note triple-dots ...):
git range-diff abc123...efg678
Example output explained:
- Each commit line shows the commit SHA before and after the rebase.
- The green lines at the top show new commits in the upstream project. Read them if you want to want to see what changed upstream since you last rebased.
- Yellow lines show commits unchanged by the rebase.
- Red lines are commits that were removed as part of your conflict resolution (e.g. if you contributed one of your patches-on-top into the upstream project).
- Green lines are commits that were added as part of your conflict resolution (e.g. if a new customisation was necessary to make your project work with the new upstream code).
Red-and-green lines show commits that were changed as part of the rebase (e.g. when a conflict resolution had to change your commit-on-top in order to work with modified upstream code).
When they appear, they also include a normal diff so you can inspect the difference.
As part of your review, you should especially check whether addition/removal of your commits-on-top look right (or if some were accidentally dropped), and whether the conflict resolution (red-and-green lines) looks correct.
来源：https://stackoverflow.com/questions/61668461/how-to-effectively-review-git-submodule-updates-rebases