Strange behaviour of git log --follow

Hello.

$ git log include/__vic/mutex.h
commit 9429293f8f8fb0819c77cf1f723567f6edc8fb6a
Merge: 96dd9a2 f484f4e
Author: __vic [off-list ref]
Date:   2017-12-13 10:41:32 +0300

     Merge branch 'generic' into posix

commit f484f4e8aae32041ba56bdce12d1efd8491e94d5
Merge: 86b848a b9bbbe6
Author: __vic [off-list ref]
Date:   2017-12-12 17:35:10 +0300

     waitable_event, thread, mutex
$ git log --follow include/__vic/mutex.h
$

Why --follow makes git produce truncated history for file 
that wasn't renamed?

My repository is available here 
https://github.com/2underscores-vic/__vic