How to restore the permissions of files and directories within git if they have been modified?

Git keeps track of filepermission and exposes permission changes when creating patches using git diff -p. So all we need is:

1. create a reverse patch
2. include only the permission changes
3. apply the patch to our working copy

As a one-liner:

git diff -p -R --no-ext-diff --no-color \    | grep -E "^(diff|(old|new) mode)" --color=never  \    | git apply

you can also add it as an alias to your git config...

git config --global --add alias.permission-reset '!git diff -p -R --no-ext-diff --no-color | grep -E "^(diff|(old|new) mode)" --color=never | git apply'

...and you can invoke it via:

git permission-reset

Note, if you shell is bash, make sure to use ' instead of " quotes around the !git, otherwise it gets substituted with the last git command you ran.

Thx to @Mixologic for pointing out that by simply using -R on git diff, the cumbersome sed command is no longer required.

Try git config core.fileMode false

From the git config man page:

core.fileMode

If false, the executable bit differences between the index and the working copy are ignored; useful on broken filesystems like FAT. See git-update-index(1).

The default is true, except git-clone(1) or git-init(1) will probe and set core.fileMode false if appropriate when the repository is created.

Git doesn't store file permissions other than executable scripts. Consider using something like git-cache-meta to save file ownership and permissions.

Git can only store two types of modes: 755 (executable) and 644 (not executable). If your file was 444 git would store it has 644.