mutt_dotlock.c

[felixs]

Hi mutt developers,

is the file mutt_dotlock.c part of mutt's source code?
What strikes me is the fact that this file is present in my
already existing mutt-1.11.3 directory (installed from a tarball and
built from source), but, as to my checks, it was NOT part of the mutt 
source code repo I cloned days ago.
I manually had to add it to my working copy.

Could someone shed some light on this?

Thanks in advance

felixs