将分支b合并到签出的分支cha的一个可能的和经过测试的解决方案:

# in case branchA is not our current branch
git checkout branchA

# make merge commit but without conflicts!!
# the contents of 'ours' will be discarded later
git merge -s ours branchB    

# make temporary branch to merged commit
git branch branchTEMP         

# get contents of working tree and index to the one of branchB
git reset --hard branchB

# reset to our merged commit but 
# keep contents of working tree and index
git reset --soft branchTEMP

# change the contents of the merged commit
# with the contents of branchB
git commit --amend

# get rid off our temporary branch
git branch -D branchTEMP

# verify that the merge commit contains only contents of branchB
git diff HEAD branchB

为了实现自动化，您可以使用branchA和branchB作为参数将其包装到脚本中。

这个解决方案保留了合并提交的第一个和第二个父节点，就像你期望git merge -s their branchB一样。

将分支b合并到签出的分支cha的一个可能的和经过测试的解决方案:

# in case branchA is not our current branch
git checkout branchA

# make merge commit but without conflicts!!
# the contents of 'ours' will be discarded later
git merge -s ours branchB    

# make temporary branch to merged commit
git branch branchTEMP         

# get contents of working tree and index to the one of branchB
git reset --hard branchB

# reset to our merged commit but 
# keep contents of working tree and index
git reset --soft branchTEMP

# change the contents of the merged commit
# with the contents of branchB
git commit --amend

# get rid off our temporary branch
git branch -D branchTEMP

# verify that the merge commit contains only contents of branchB
git diff HEAD branchB

为了实现自动化，您可以使用branchA和branchB作为参数将其包装到脚本中。

这个解决方案保留了合并提交的第一个和第二个父节点，就像你期望git merge -s their branchB一样。

旧版本的git允许你使用“their”合并策略:

git pull --strategy=theirs remote_branch

但是这已经被删除了，正如Junio Hamano (Git维护者)在这条消息中解释的那样。正如链接中提到的，相反，你会这样做:

git fetch origin
git reset --hard origin

但是要注意，这与实际的合并不同。你的解决方案可能就是你真正在寻找的选项。

我觉得你真正想要的是

git checkout -B mergeBranch branchB
git merge -s ours branchA
git checkout branchA
git merge mergeBranch
git branch -D mergeBranch

这看起来很笨拙，但应该有用。我唯一不喜欢这个解决方案的是git的历史会令人困惑…但至少历史记录将被完全保存，您不需要为删除的文件做什么特别的事情。

这个答案是由Paul Pladijs给出的。为了方便起见，我只是把他的命令做了一个git别名。

编辑你的.gitconfig并添加以下内容:

[alias]
    mergetheirs = "!git merge -s ours \"$1\" && git branch temp_THEIRS && git reset --hard \"$1\" && git reset --soft temp_THEIRS && git commit --amend && git branch -D temp_THEIRS"

然后你可以“git merge -s their A”通过运行:

git checkout B (optional, just making sure we're on branch B)
git mergetheirs A

这一个使用了git管道命令读树，但是使得整个工作流程更短。

git checkout <base-branch>

git merge --no-commit -s ours <their-branch>
git read-tree -u --reset <their-branch>
git commit

# Check your work!
git diff <their-branch>