agent: New option --s2k-count.

* agent/agent.h (opt): New field 's2k_count'.
* agent/gpg-agent.c (oS2KCount): New enum value.
(opts): New option --s2k-count.
(parse_rereadable_options): Set opt.s2k_count.
--

This option is useful to speed up the starting of gpg-agent and in
cases where the auto-calibration runs into problems due to a broken
time measurement facility.

Signed-off-by: Werner Koch <wk@gnupg.org>
(cherry picked from commit f7212f1d11)

agent/gpg-agent.c

@@ -134,6 +134,8 @@ enum cmd_and_opt_values
   oPuttySupport,
   oDisableScdaemon,
   oDisableCheckOwnSocket,
+  oS2KCount,
+
   oWriteEnvFile
 };
 
@@ -248,6 +250,8 @@ static ARGPARSE_OPTS opts[] = {
                 ),
   ARGPARSE_s_n (oEnableExtendedKeyFormat, "enable-extended-key-format", "@"),
 
+  ARGPARSE_s_u (oS2KCount, "s2k-count", "@"),
+
   /* Dummy options for backward compatibility.  */
   ARGPARSE_o_s (oWriteEnvFile, "write-env-file", "@"),
   ARGPARSE_s_n (oUseStandardSocket, "use-standard-socket", "@"),
@@ -819,6 +823,7 @@ parse_rereadable_options (ARGPARSE_ARGS *pargs, int reread)
       disable_check_own_socket = 0;
       /* Note: When changing the next line, change also gpgconf_list.  */
       opt.ssh_fingerprint_digest = GCRY_MD_MD5;
+      opt.s2k_count = 0;
       return 1;
     }
 
@@ -910,6 +915,10 @@ parse_rereadable_options (ARGPARSE_ARGS *pargs, int reread)
         opt.ssh_fingerprint_digest = i;
       break;
 
+    case oS2KCount:
+      opt.s2k_count = pargs->r.ret_ulong;
+      break;
+
     default:
       return 0; /* not handled */
     }