Question

Can I perform ‘merge’ that updates only existing files in current branch?

For example, I have branch1: /file1, /x/file2, /file3. And branch2: /file1, /x/file2, /z/file4. I want to update files file1 and file2 in second branch with files from first.

As a solution I see creating separate commits in branch1 for that files, and than use chery-pick in second branch.

UPD:
Thanks to @fge, I’ve founded that solution (not so simple as I had expected):

git co branch2
git co branch1 -- ./
git reset ./
git ci -a
git clean -f

Answer 1

You can proceed as such while on branch2:

git checkout branch1 -- file1 x/file2

Then git add the modified files and commit the result.

If you want to have the commit message of branch1 as well, you could commit with git commit -c branch1.

Note that branch1 really is a refspec. A branch in git is nothing but a commit, but as a commit has links to its parent(s), it is, in effect, a “branch”.