Git日志分支拆分

Question

I've been doing some work on a project managed with git. At some point I created a branch with

git -b my-branch

did some work ,commited and pushed to the remote repo. Later, I merged with:

git checkout master
git merge my-branch
git push

But when i look at the graph with gitlab i do not see the branches splitting, just something like this

* * * * * * * 
            ^
            |
         my-branch

When i'd expect something like

* * * * * * *
    \-------^
            |
        my-branch

Why is this ?

Answer 1

This is probably because of fast-forwarding. If Git doesn't need to do a merge, it won't. This happens when you merge a branch but have made no changes to its parent.

A - B - C - D - E [master]
                 \
                  F - G - H [feature]

In this repo there have been no changes to master since feature was branches. master is an ancestor of feature . That apparent branch between E and F isn't really there, the history is straight.

If you git checkout master; git merge feature git checkout master; git merge feature it will "fast-forward" and you'll wind up with this.

                              [master]
A - B - C - D - E - F - G - H [feature]

master is moved to the same commit as feature , no merge is done.

---

You can turn this off with git merge --no-ff . I recommend this when merging feature branches to avoid losing important information to understand the code. In the example above, there's no evidence that F, G, and H were done as a single feature. There's no link to the ticket discussing the feature.

Instead if we had git checkout master; git merge --no-ff feature git checkout master; git merge --no-ff feature this would force Git to merge even if it didn't have to.

A - B - C - D - E ---------- I [master]
                 \         /
                  F - G - H [feature]

I is the merge commit and you get a nice feature bubble.