问题
On daily routine i use SmartGit
as client of choose. My team members however stick to git native, non commercial GUI. We discovered some differences in how our merge commits looks like.
Those are options that SmartGit
gives when requested to merge branch:
On below graph you can see my example SmartGit graph output, containing:
- single
master
branch - One branch merged to master with
merge commit
option - One branch merged with
simple commit
option
One of branches (with_merge_branch
) is visualizing merge operation by joining branch with master via line. Second one (normal_commit_branch
) does not.
Question is, how to enforce both behaviors in native git commands? I.e. whats the difference between those two commits?
回答1:
The difference between the two kinds of merge are only different in the commit history (as you showed the logs in graph).
Let's illustrate by graphs. Assume the commit history as below before merging:
A---B---C---D master
\
E---F---G develop
Merge commit (multiple parents):
The command used is git merge branchname
. It's the default way to merge two branches.
When you merge develop
branch into master
branch by Merge commit in SmartGit (git merge develop
), the commit history will be:
A---B---C---D---M master
\ /
E---F---G develop
Simple commit (one parent, "squash"):
It merges two branches with --squash
option, the command used is git merge branchname --squash
.
--squash
Produce the working tree and index state as if a real merge happened (except for the merge information), but do not actually make a commit, move the HEAD, or record $GIT_DIR/MERGE_HEAD (to cause the next git commit command to create a merge commit). This allows you to create a single commit on top of the current branch whose effect is the same as merging another branch (or more in case of an octopus).
When you merge develop
branch into master
branch by simple commit in SmartGit (git merge develop --squash
), it get the changes from develop
branch into master
branch as a new ordinary commit (as if a real merge happened), and the commit history will be:
A---B---C---D---M master
\
E---F---G develop
回答2:
merge commits
are just commit
but the difference is they have more than one parents.
as you know commits may or may not have parent commit, in fact the merge commit
is the commit
that have more than one parent commit
.
来源:https://stackoverflow.com/questions/47089913/merge-commit-vs-normal-commit