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I'm trying to merge a few subdirectories from a remote git repository to my repository. Both Remote and Local Repositories include the whole kernel repository and I'm interested only in the wireless relevant files. I tried to follow the instructions under "How to use the subtree merge strategy", but since most of the files exist both in local repository and in remote repository the git read-tree --prefix=dir-B/ -u Bproject/master command fails. I could not use -m option and --prefix in the same command line.

This merge actually should update (merge/pull) all relevant wireless directories/files according to the files in the remote repository where conflicts should be solve by preferring the remote files.

To make my question general -- say you have repository A and B. both have the folder wireless_dir: A/wireless_dir, B/wireless_dir. I'm working on repository B and would like to update all its files in B/wireless_dir from A/wireless_dir where changes in A/wireless_dir are preferred when merge conflicts occur.

Jonathan Leffler
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Nisim
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  • Is this the Linux kernel? Doesn't it use submodules for components like that - meaning they'd already be separate repositories? – Cascabel Mar 20 '11 at 18:56

2 Answers2

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From what Jeformi commented, it appears you already have the situation where the folder is a separate repository, which if that's the case all you have to do is a git pull.

However, if the commits you're looking for have files from other folders that you don't want, Git allows you to "unsqaush" commits in a round about way as mentioned here: redhatmagazine

The steps to do this (a bit more generalized to your situation) are:

1) Make note of the commit your HEAD is currently at, let's call it <OLD_HEAD> for fun. This can be obtained from the log and looking at the most recent commit's sha1 by using:

git log

2) Pull in the changes from repo A into your branch (this will include any that you might not want):

git pull <repo A> <branch_name>

3) Now's it's time to use <OLD_HEAD> (in a non-vulgar way)... this is done by a reset

git reset --mixed <OLD_HEAD>

4) With everything you've done you're HEAD is back at <OLD_HEAD> and your index is as well, but in your working directory you now have the changes from repo A that you've been looking for, as well as the potential for files outside of the wireless_dir folder. To interactively merge these files in your working directory into your index use (only on the files from wireless_dir if that's all you want):

git add --patch <filename>

5) And finally:

git commit -m “Selectively merged my files”

Note: If you don't want to chance screwing up your branch, make a new branch before trying the above.

Hazok
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  • @Karl Still not enough rep to comment on other answers, but what you described is what I already answered in explicit steps, except that you don't have to manually copy the folder outside the tree. – Hazok Apr 06 '11 at 04:18
  • Argh, no newlines for whitespace in comments... @Karl again ;) That is a good point about the dependencies, but doing a cherry-pick doesn't guarantee pulling in dependencies, especially if the commits aren't organized well. Also, since the questioner is asking about pulling in the specific wireless_dir folder without pulling in anything else, then my guess is he's made changes outside of that wireless_dir folder that he doesn't want to be modified when pulling in the changes from wireless_dir, of which the commits grabbed with cherry-pick could merge into his changes. – Hazok Apr 06 '11 at 04:22
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The easiest way to do it is to merge the entire branch, copy that folder outside of your git tree, undo or abort the merge, then copy the folder back in.

However, you're going to have problems if any of the changes have dependencies outside that folder. You probably want to cherry-pick the entire commits of anything that touches that folder (from git log subdir) to pull in the dependencies.

Karl Bielefeldt
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