'git status' shows changed files, but 'git diff' doesn't

Question

I\'ve had a look at all similar questions. However, I\'ve double checked and something strange is definitely happening.

On one server (Solaris with Git 1.8.1) I clon

Answer 1

Short Answer

Running git add sometimes helps.

Example

Git status is showing changed files and git diff is showing nothing...

> git status
On branch master
Changes not staged for commit:
  (use "git add ..." to update what will be committed)
  (use "git checkout -- ..." to discard changes in working directory)

        modified:   package.json

no changes added to commit (use "git add" and/or "git commit -a")
> git diff
> 

...running git add resolves the inconsistency.

> git add
> git status
On branch master
nothing to commit, working directory clean
>