I agree, merges are great, since you have a single commit you can pull out.
To back out a merge, you would just do another merge with a reverse diff: `git merge merge-commit..merge-commit^`
Also, it makes things like backporting much easier, since you can just pull out the merge commit and it brings in any "subcommits", rather than individually cherry-picking each commit, like you'd have to do with a fast-forward.
It also makes life so much easier on other developers that are just working in feature branches. No need to rebase. No need to squash. No need to clean up commits. We allow merging master back into your feature branch rather than rebasing, since in the end it doesn't matter (and sometimes, everything you did is interesting).
That works if you have one commit. Otherwise it's more like git commit, git merge --no-ff master, git commit, git merge --no-ff master, git commit, git merge --no-ff master… which shows as bunch of really ugly and unnecessary merge commits from master to feature branch. In contrast, I can do 50 times git rebase and you wouldn't know.
Those merges from master into a feature branch are useful though. If there is a conflict that you have to resolve in your feature branch, then there is a clear place where you did it, and that can be double checked. If you are rebasing, then when I review your feature branch, I have no idea if you had conflicts, and if so, how many and how you resolved them.
git should be used like an audit log, where you can trace the thought process and actions of your developers. Erasing that by rebasing/squashing for a "clean" log isn't worth it in my opinion.
I'd much rather see 40 commits across two weeks on your branch than one "clean" commit with everything. With the 40 commits, I can trace back through your work, and understand your challenges (sometimes seeing 5 commits in a row with 'trying to get X to work' is really useful).
Now, do I want all that detail once your branch is in master. Absolutely Not! I just want a single merge commit that brings in your whole branch. Unfortunately, `git log` shows everything, which is why I advocate for `git log --first-parent` being the default.
If git log's default behavior wasn't so terrible, I don't think this argument would even come up so often.
Exactly. And if the default view of `git log` wasn't so terrible (if it acted like git log --first-parent), then I think a lot more people would do that too.
But I understand why people who just use `git log` complain with merge commits. It is frustratingly hard to see what actually happened, because subcommits from that merge branch show up in the past in your linear timeline and aren't grouped together. It clutters your log and makes it really hard to tell what is going on and what commits are related to each other.
bazaar's (now called breezy) log (which we used before moving to git) was really nice. By default, it only showed first parents (direct commits or merges). And if you wanted to see more than that, it grouped merges together. This is what happens when you call `bzr log --include-merged` to show not just the top level merges/commits, but also the sub-commits from each merge:
------------------------------------------------------------
revno: 33 [merge]
committer: John Doe <john.doe@example.com>
branch nick: master
timestamp: Tue 2013-09-03 11:39:37 -0500
message:
Fixed bug #413 - Add in a blend option
------------------------------------------------------------
revno: 32.1.2
committer: John Doe <john.doe@example.com>
branch nick: fix-413
timestamp: Tue 2013-09-03 10:07:03 -0500
message:
Merged the Role changes from fix-412
------------------------------------------------------------
revno: 32.1.1
committer: John Doe <john.doe@example.com>
branch nick: fix-413
timestamp: Tue 2013-09-01 10:04:28 -0500
message:
Some initial work on a blend mode
------------------------------------------------------------
revno: 32 [merge]
committer: John Doe <john.doe@example.com>
branch nick: master
timestamp: Tue 2013-09-03 09:17:27 -0500
message:
Fixed bug #408 - Make the interface prettier
------------------------------------------------------------
revno: 29.2.3 [merge]
committer: John Doe <john.doe@example.com>
branch nick: fix-408
timestamp: Wed 2013-09-02 15:31:32 -0500
message:
mft
------------------------------------------------------------
revno: 29.2.2
committer: John Doe <john.doe@example.com>
branch nick: fix-408
timestamp: Wed 2013-08-24 12:13:17 -0500
message:
Fixed multiline support
------------------------------------------------------------
revno: 29.2.1
committer: John Doe <john.doe@example.com>
branch nick: fix-408
timestamp: Wed 2013-08-22 11:58:48 -0500
message:
Added directories for other layouts. Changed out the logo, and force a size during the signon
------------------------------------------------------------
revno: 31 [merge]
committer: John Doe <john.doe@example.com>
branch nick: master
timestamp: Wed 2013-08-28 15:13:24 -0500
message:
Fixed bug #404 - Pressing back in the preferences exits the application
------------------------------------------------------------
revno: 30.1.1
committer: John Doe <john.doe@example.com>
branch nick: fix-404
timestamp: Wed 2013-08-28 15:11:24 -0500
message:
Got rid of the no history junk. It looks like the problem can be solved by calling finish
The top level merges are in order by commit/date, while the sub-commits in each branch and in order with respect to their parent, not the entire repo!
This even resolves stuff, like in revno 29.2.3 where the master branch is merged into the feature branch (fix-408) to get fix-408 up to date.
Comments
I agree, merges are great, since you have a single commit you can pull out.
To back out a merge, you would just do another merge with a reverse diff: `git merge merge-commit..merge-commit^`
Also, it makes things like backporting much easier, since you can just pull out the merge commit and it brings in any "subcommits", rather than individually cherry-picking each commit, like you'd have to do with a fast-forward.
It also makes life so much easier on other developers that are just working in feature branches. No need to rebase. No need to squash. No need to clean up commits. We allow merging master back into your feature branch rather than rebasing, since in the end it doesn't matter (and sometimes, everything you did is interesting).
Agree as well. In the team we all do:
- git checkout -b "new-branch"
- git commit
- git merge --no-ff master (to get the latest from master into our branches)
- git push
That's all you need. No rebase or force pushes. Easy.
That works if you have one commit. Otherwise it's more like git commit, git merge --no-ff master, git commit, git merge --no-ff master, git commit, git merge --no-ff master… which shows as bunch of really ugly and unnecessary merge commits from master to feature branch. In contrast, I can do 50 times git rebase and you wouldn't know.
Those merges from master into a feature branch are useful though. If there is a conflict that you have to resolve in your feature branch, then there is a clear place where you did it, and that can be double checked. If you are rebasing, then when I review your feature branch, I have no idea if you had conflicts, and if so, how many and how you resolved them.
git should be used like an audit log, where you can trace the thought process and actions of your developers. Erasing that by rebasing/squashing for a "clean" log isn't worth it in my opinion.
I'd much rather see 40 commits across two weeks on your branch than one "clean" commit with everything. With the 40 commits, I can trace back through your work, and understand your challenges (sometimes seeing 5 commits in a row with 'trying to get X to work' is really useful).
Now, do I want all that detail once your branch is in master. Absolutely Not! I just want a single merge commit that brings in your whole branch. Unfortunately, `git log` shows everything, which is why I advocate for `git log --first-parent` being the default.
If git log's default behavior wasn't so terrible, I don't think this argument would even come up so often.
Exactly. And if the default view of `git log` wasn't so terrible (if it acted like git log --first-parent), then I think a lot more people would do that too.
But I understand why people who just use `git log` complain with merge commits. It is frustratingly hard to see what actually happened, because subcommits from that merge branch show up in the past in your linear timeline and aren't grouped together. It clutters your log and makes it really hard to tell what is going on and what commits are related to each other.
bazaar's (now called breezy) log (which we used before moving to git) was really nice. By default, it only showed first parents (direct commits or merges). And if you wanted to see more than that, it grouped merges together. This is what happens when you call `bzr log --include-merged` to show not just the top level merges/commits, but also the sub-commits from each merge:
The top level merges are in order by commit/date, while the sub-commits in each branch and in order with respect to their parent, not the entire repo!This even resolves stuff, like in revno 29.2.3 where the master branch is merged into the feature branch (fix-408) to get fix-408 up to date.