gpgv: New option --enable-special-filenames.

* g10/gpgv.c (oEnableSpecialFilenames): New.
(opts): Add option --enable-special-filenames.
(main): Implement that option.
--

This is the same option we have in gpg.  It allows to use commands
like

 gpgv --enable-special-filenames -- '-&3' - <msg 3<msg.sig

Signed-off-by: Werner Koch <wk@gnupg.org>

doc/gpgv.texi

@@ -128,6 +128,12 @@ supplied multiple times if multiple algorithms should be considered
 weak.  MD5 is always considered weak, and does not need to be listed
 explicitly.
 
+@item --enable-special-filenames
+@opindex enable-special-filenames
+This option enables a mode in which filenames of the form
+@file{-&n}, where n is a non-negative decimal number,
+refer to the file descriptor n and not to a file with that name.
+
 @end table
 
 @mansect return value

g10/gpgv.c

@@ -63,6 +63,7 @@ enum cmd_and_opt_values {
   oLoggerFD,
   oHomedir,
   oWeakDigest,
+  oEnableSpecialFilenames,
   aTest
 };
 
@@ -83,6 +84,7 @@ static ARGPARSE_OPTS opts[] = {
   ARGPARSE_s_s (oHomedir, "homedir", "@"),
   ARGPARSE_s_s (oWeakDigest, "weak-digest",
                 N_("|ALGO|reject signatures made with ALGO")),
+  ARGPARSE_s_n (oEnableSpecialFilenames, "enable-special-filenames", "@"),
 
   ARGPARSE_end ()
 };
@@ -201,6 +203,9 @@ main( int argc, char **argv )
           additional_weak_digest(pargs.r.ret_str);
           break;
         case oIgnoreTimeConflict: opt.ignore_time_conflict = 1; break;
+        case oEnableSpecialFilenames:
+          iobuf_enable_special_filenames (1);
+          break;
         default : pargs.err = ARGPARSE_PRINT_ERROR; break;
 	}
     }