How do I commit case-sensitive only filename changes in Git?

Git has a configuration setting that tells it whether to be case sensitive or insensitive: core.ignorecase. To tell Git to be case-senstive, simply set this setting to false:

git config core.ignorecase false

Documentation

From the git config documentation:

core.ignorecase

If true, this option enables various workarounds to enable git to work better on filesystems that are not case sensitive, like FAT. For example, if a directory listing finds makefile when git expects Makefile, git will assume it is really the same file, and continue to remember it as Makefile.

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

Case-insensitive file-systems

The two most popular operating systems that have case-insensitive file systems that I know of are

• Windows
• OS X

Using SourceTree I was able to do this all from the UI

1. Rename FILE.ext to whatever.ext
2. Stage that file
3. Now rename whatever.ext to file.ext
4. Stage that file again

It's a bit tedious, but if you only need to do it to a few files it's pretty quick

This is what I did on OS X:

git mv File file.tmp
git mv file.tmp file

Two steps because otherwise I got a “file exists” error. Perhaps it can be done in one step by adding --cached or such.

Sometimes it is useful to temporarily change Git's case sensitivity.

Method #1 - Change case sensitivity for a single command:

git -c core.ignorecase=true checkout mybranch to turn off case-sensitivity for a single checkout command. Or more generally: git -c core.ignorecase= <<true or false>> <<command>>. (Credit to VonC for suggesting this in the comments.)

Method #2 - Change case sensitivity for multiple commands:

To change the setting for longer (e.g. if multiple commands need to be run before changing it back):

1. git config core.ignorecase (this returns the current setting, e.g. false).
2. git config core.ignorecase <<true or false>> - set the desired new setting.
3. ...Run multiple other commands...
4. git config core.ignorecase <<false or true>> - set config value back to its previous setting.

Under OSX, to avoid this issue and avoid other problems with developing on a case-insensitive filesystem, you can use Disk Utility to create a case sensitive virtual drive / disk image.

Run disk utility, create new disk image, and use the following settings (or change as you like, but keep it case sensitive):

Make sure to tell git it is now on a case sensitive FS:

git config core.ignorecase false