port-line broken?

[hjstein@bfr.co.il (Harvey J. Stein)]

The guile docs say:

 - primitive: port-line [INPUT-PORT]
     Return the current column number or line number of INPUT-PORT,
     using the current input port if none is specified.  If the number
     is unknown, the result is #f.  Otherwise, the result is a 0-origin
     integer - i.e. the first character of the first line is line 0,
     column 0.  (However, when you display a file position, for example
     in an error message, we recommand you add 1 to get 1-origin
     integers.  This is because lines and column numbers traditionally
     start with 1, and that is what non-programmers will find most
     natural.)
 

However, it doesn't seem to work:

   guile> (define p (open-input-file "extract.scm"))
   guile> (port-line p)
   0
   guile> (read-line p)
   "#!/bin/sh"
   guile> (read-line p)
   "exec guile -l $0 -- --run-from-shell \"$@\""
   guile> (read-line p)
   "!#"
   guile> (read-line p)
   ";;; extract.scm"
   guile> (read-line p)
   ";;; Copyright (C) 1998, Harvey J. Stein, hjstein@bfr.co.il"
   guile> (port-line p)
   0

Is this broken, or is it me?

-- 
Harvey J. Stein
BFM Financial Research
hjstein@bfr.co.il