🚀 go-pugleaf

I've been looking at the coffread module and how it processes the 
symbols of ".file".  I'm working with version 3.5.  In the read_coff_symtab
function there is a block of code which calls complete_symtab ("_globals_"...
It seems that the only entry into this block is based upon reading a
bogus ".file" symbol that doesn't have a C_FILE n_sclass.  I haven't 
found any documentation of such a ".file" symbol in the Understanding
and Using COFF book that I am using for reference.  What I have found
(on page 107) is that the .file symbol value is an index which forms
a circular list, with the last .file value having an index to the first
.file symbol.  If implemented this way, the variable "next_file_symnum"
will eventually get set back to a value smaller than the current
symbol number, and the section which calls complete_symtab ("_globals_"...
will never be entered.  So - the code seems to be expecting this
undocumented termination '.file' block.  Can you comment on this?  
Jay Norwood