how to force manual merge with git instead of fast forward

Question

I created a branch to solve an issue. In this branch I put many debug lines to identify the problem and I fixed it. So I have:

* (issue_b47)    Without the bug but with a lot of useless debug things
* (HEAD, master) With the bug

If I simply write this

git checkout master
git merge issu_b47

git will do a fast forward merge and I will then inherit all the debug things I don't want.

What I would like to do is to do a manual merge with my difftool . How to do it?

I think it easier to clearly see on the left panel of my difftool the issue_b47 branch and on the right panel the master branch. I can just decide to keep what is relevant to solve the issue, save the diff and finalize the merge. Is there any to do it so with git?

Answer 1

it sounds like you want the commit on the branch to be altered a bit. There's many ways to do that. Here are a couple common ones:

1. Fix up the contents (get rid of the debug stuff), then git add -A; git commit --amend git add -A; git commit --amend on your branch, then merge as normal.

2. git reset --soft HEAD~1 while on the branch, then git reset HEAD . , will pull everything back out and let you start the commit over again. You will have unstaged changes.

Answer 2

通过使用此命令，可以避免快进

git merge --no-ff branchname

Answer 3

From iss_b47 branch

git difftool HEAD~1 -- <file>

Presuming you have a suitable difftool configured you will get a side by side pane where you can move changes back and forth and then save the result. At that point you can git commit --amend and then git merge.

In the off change you happened to do git commit on just your debug changes and then did git commit --amend with the bug fix then you can use the reflog to extract the changes automatically.

Answer 4

Use --no-commit to force no commit, and --squash to create it's own commit rather than the same commit as (issue_b47)

git merge --no-commit --squash issu_b47

After this command, git will do the auto-merge and put the modified files in INDEX. You can find the modified files by git status .

At this stage you can use whatever tool to do your manual merge. After that git add + git commit to finish your merge. You will get a separate commit from the issue_b47 as it used to be in fast forward (which is normal because they have different changes in both commits)