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gitgit-cherry-pick

How can I disable git cherry-pick from applying the diff of one file to another?


The steps to reproduce my case,

git init foo
cd foo

# add initial a.txt on "master"
echo hello > a.txt
git add a.txt
git commit -mbase

# create branch "new"
git branch new

# on "master", rename a.txt to b.txt
git mv a.txt b.txt
git commit -m'rename a.txt to b.txt'

# on "master", modify b.txt
echo world >> b.txt
git commit -am'world b'

# on "new" rename a.txt to c.txt
git switch new
git mv a.txt c.txt
git commit -m'rename a.txt to c.txt'   # Anchor 1

# apply the commit in which b.txt is modified
git cherry-pick master

As on branch new, b.txt does not exist and it has only c.txt, I expected git cherry-pick to fail due to conflicts. However, it succeeded and applied the diff of b.txt to c.txt.

I guess it's related to the fact that b.txt and c.txt are considered as being copied from the same origin a.txt, and maybe also some git merge strategy. I had a try to solve the issue,

# remove foo, run the commands again, and pause at # Anchor 1

# introduce b.txt from "master" to "new"
git checkout master -- b.txt
git commit -m'add b.txt from master'

# apply the commit in which b.txt is modified
git cherry-pick master

This way, it complains nothing to commit, working tree clean as expected. But, in one of my projects the situation is very common, and I cannot abandon git cherry-pick in the workflow. As the creation and renaming are not under my control, I cannot ask other team members to always apply all new files to other branches where they are not necessary at all.

Is there any solution to disable git cherry-pick from applying the diff of one file to another without any bad side effect? Thanks.

I tried git 2.19.2, 2.24.1 and 2.39.0 on Ubuntu.


Solution

  • The ‘resolve’ merge strategy…

    […] does not handle renames.

    https://git-scm.com/docs/git-merge#Documentation/git-merge.txt-resolve

    Use --strategy to choose ‘resolve’.

    https://git-scm.com/docs/git-cherry-pick#Documentation/git-cherry-pick.txt---strategyltstrategygt

    Continuing from anchor 1 as an example:

    $ git cherry-pick --strategy=resolve master
    Trying simple merge.
    Simple merge failed, trying Automatic merge.
    ERROR: b.txt: Not handling case … ->  -> …
    fatal: merge program failed
    error: could not apply …... world b
    
    $ git status
    On branch new
    You are currently cherry-picking commit ….
    
    Unmerged paths:
        deleted by us:   b.txt
    
    no changes added to commit