How to apply a patch(copy only some lines from experimental to suggestFix branch) from experimental branch(local) onto suggestFix branch(local)?

Question

So I have 3 branches: master, suggestFix and experimental. suggestFix points at the same place as master because I want to use master as a starting point to create pull request on GitHub. Experimental has different commits, and I want to move to suggestFix branch only some lines of code from experimental.

I'll provide a concrete example. Here's final file on experimental branch:

And here are master and suggestFix branches:

I want my suggestFix branch to look like this after I do whatever is needed with git tools:

I don't care how history looks like as long as I can make a pull request and it will look like I modified master and got from master to suggestFix with line insertions(as it usually shows in pull requests on GitHub).

I understand that I will need to review every single line of every single file and either accept or reject edits of lines or how they are also called hunks of code. That's what I want. I use a mix of Atlassian Sourcetree and MINGW64. I managed to start some kind of diff on Sourcetree:

But I don't understand how to do per-line patch and get to a file that I need(that you can see above on the third picture). Please help, I've been trying to do it for hours.

Here's a GitHub repository with that specific example:

https://github.com/KulaGGin/GitPatch

Answer 1

So I have 3 branches: master, suggestFix and experimental. suggestFix points at the same place as master because I want to use master as a starting point to create pull request on GitHub. Experimental has different commits, and I want to move to suggestFix branch only some lines of code from experimental.

Answer to this is to switch to suggestFix branch, then run git merge experimental --squash. This will squash all the commits from experimental into a single commit and stage them. So unstage all the changes first and then run git add --patch <filename> to pick hunks of code you want to commit. Detailed explanation. Or you can more easily do it in a tool with UI like Sourcetree:

Then you just commit the changes you staged on the suggestFix branch. Then you can remove all unstaged changes with git reset --hard.