By default, Mac OS X uses a case insensitive file system, and Git seems to honor that. The problem is, most programming languages, especially Java, are case sensitive. Class "JavaScriptSupport" needs to be in file "JavaScriptSupport.java" and not "JavascriptSupport.java". This is even worse when sharing code via a repository since some other developers may check out code on a case sensitive file system.
I was just renaming some classes, from things like "JavascriptStack" to "JavaScriptStack" (because the language is called "JavaScript" not "Javascript") ... and I was dismayed that Git saw that as an in-place update to a file, not a rename of the file.
Unfortunately, it's not as simple as git config core.ignorecase false to make Git do the right thing. That's an essential part of it, but Git still sees changes to the original naming of the file as a change, not a deletion.
I had to use the trick of one commit renaming JavascriptStack.java --> JSStack.java, then a second commit renaming JSStack.java --> JavaScriptStack.java.
