core: Fix translations of --help

* src/argparse.c (show_help): Do not translate the empty string.
--

PO files use the empty string for meta information.  However, to mark
the end of the heder group we also use an empty string and that one
gets translated - boom.  Example of this error:

  [...]
   -u, --local-user USER-ID           [...]

  Project-Id-Version: gnupg-2.3.0
  Report-Msgid-Bugs-To: translations@gnupg.org
  PO-Revision-Date: 2022-10-07 09:52+0200
  Last-Translator: Werner Koch <wk@gnupg.org>
  Language-Team: German <de@li.org>
  Language: de
  MIME-Version: 1.0
  Content-Type: text/plain; charset=UTF-8
  Content-Transfer-Encoding: 8bit
  Plural-Forms: nplurals=2; plural=n != 1;
  :

  (Auf der "man"-Seite ist eine volls[...]

1 files changed, 7 insertions, 2 deletions

diff --git a/src/argparse.c b/src/argparse.c
index ef0c161..8651e00 100644
--- a/src/argparse.c
+++ b/src/argparse.c
@@ -2937,7 +2937,7 @@ cmp_ordtbl (const void *a_v, const void *b_v)
  *    this option
  *  - a description which starts with a '@' and is followed by
  *    any other characters is printed as is; this may be used for examples
- *    and such.  This is a legacy methiod, moder codes uses the flags
+ *    and such.  This is a legacy method, modern code uses the flags
  *    ARGPARSE_OPT_VERBATIM or ARGPARSE_OPT_HEADER.
  *  - A description which starts with a '|' outputs the string between this
  *    bar and the next one as arguments of the long option.
@@ -3000,7 +3000,12 @@ show_help (opttable_t *opts, unsigned int nopts, unsigned int flags)
         writestrings (0, "Options:", "\n", NULL);
       for (i=0; i < nopts; i++ )
         {
-          s = map_fixed_string (_( opts[ordtbl[i]].description ));
+          /* Do not translate the empty string becuase it is used as
+           * the identification of the PO file.  */
+          if (opts[ordtbl[i]].description && *opts[ordtbl[i]].description)
+            s = map_fixed_string (_( opts[ordtbl[i]].description ));
+          else
+            s = "";
           if ( s && *s== '@' && !s[1] ) /* Hide this line.  */
             continue;
           if ( s && (opts[ordtbl[i]].flags & ARGPARSE_OPT_HEADER))