small note about 'rm' portability

[Bruno Haible]

Seen on NetBSD 2.0.2:

$ rm -rf
usage: rm [-f|-i] [-dPRrvW] file ...
$ type rm
rm is hashed (/bin/rm)

I think this qualifies as a portability pitfall. How about documenting it?


2006-10-24  Bruno Haible  <address@hidden>

        * doc/autoconf.texi (Limitations of Usual Tools): One more note about
        rm.

*** doc/autoconf.texi   23 Oct 2006 06:12:40 -0000      1.1099
--- doc/autoconf.texi   24 Oct 2006 20:39:29 -0000
***************
*** 13597,13602 ****
--- 13597,13605 ----
  @prindex @command{rm}
  The @option{-f} and @option{-r} options are portable.
  
+ @samp{rm -rf} without arguments does nothing on many systems, but fails
+ with an error message on NetBSD 2.0.2.
+ 
  A file might not be removed even if its parent directory is writable
  and searchable.  Many Posix hosts cannot remove a mount point, a named
  stream, a working directory, or a last link to a file that is being