Bug: Assertion failed: function prefix_pathspec, file pathspec.c, line 317.

The following error happens when I'm running "git add ." in the submodule dir:

$ GIT_TRACE=1 git add . 23:25:18.313575 git.c:350 trace: built-in: git 'add' '.' Assertion failed: (item->nowildcard_len <= item->len && item->prefix <= item->len), function prefix_pathspec, file pathspec.c, line 317. Abort trap: 6

Then git crashes, so I've to remove index.lock manually (.git/modules/Foo/index.lock).

This is what I did before it start doing this:
1. I've renamed GitHub repository to different name.
2. Created new repository in place of the old one (which consist other
submodules).
3. In previously cloned submodule dir (which was pointing to previous
repo before rename) I did: git fetch origin
4. Then I did: git reset origin/master --hard
5. 'git status' looks ok
6. Moved some of the files into submodule dir of the current submodule
and entered that dir.
7. From now on, the git add crashes with trap 6:  git add .

Probably there are some easier steps to reproduce the issue, but this is what I did.

OS: macOS Sierra
git version 2.8.4

(lldb) bt
* thread #1: tid = 0x2338e, 0x00007fffbe6a1dda
libsystem_kernel.dylib`__pthread_kill + 10, queue =
'com.apple.main-thread', stop reason = signal SIGABRT
  * frame #0: 0x00007fffbe6a1dda libsystem_kernel.dylib`__pthread_kill + 10
    frame #1: 0x00007fffbe78c797 libsystem_pthread.dylib`pthread_kill + 90
    frame #2: 0x00007fffbe607440 libsystem_c.dylib`abort + 129
    frame #3: 0x00007fffbe5ce8b3 libsystem_c.dylib`__assert_rtn + 320
    frame #4: 0x00000001000d83f9 git`parse_pathspec + 2917
    frame #5: 0x0000000100002ded git`cmd_add + 991
    frame #6: 0x0000000100001e64 git`handle_builtin + 357
    frame #7: 0x0000000100001877 git`main + 288

Other people could reproduce the same thing, also on Mac, see: http://stackoverflow.com/q/23205961

Kind regards, kenorb