Implementing --allow-missing-torrc CLI option.

changes/ticket10060

@@ -0,0 +1,6 @@
+  o Minor features:
+    - Adding --allow-missing-torrc commandline option 
+      that allows Tor to run if configuration file specified
+      by -f is not available, but default torrc is. 
+      Implements ticket 10060.
+

doc/tor.1.txt

@@ -45,6 +45,10 @@ COMMAND-LINE OPTIONS
     options. (Default: $HOME/.torrc, or @CONFDIR@/torrc if that file is not
     found)
 
+[[opt-allow-missing-torrc]] **--allow-missing-torrc**::
+    Do not require that configuration file specified by **-f** exist if 
+    default torrc can be accessed.
+
 [[opt-defaults-torrc]] **--defaults-torrc** __FILE__::
     Specify a file in which to find default values for Tor options.  The
     contents of this file are overridden by those in the regular

src/or/config.c

@@ -1816,6 +1816,7 @@ static const struct {
   int takes_argument;
 } CMDLINE_ONLY_OPTIONS[] = {
   { "-f",                     1 },
+  { "--allow-missing-torrc",  0 },
   { "--defaults-torrc",       1 },
   { "--hash-password",        1 },
   { "--dump-config",          1 },
@@ -4016,8 +4017,13 @@ options_init_from_torrc(int argc, char **argv)
   } else {
     cf_defaults = load_torrc_from_disk(cmdline_only_options, 1);
     cf = load_torrc_from_disk(cmdline_only_options, 0);
-    if (!cf)
-      goto err;
+    if (!cf) {
+      if (config_line_find(cmdline_only_options, "--allow-missing-torrc")) {
+        cf = tor_strdup("");
+      } else {
+        goto err;
+      }
+    }
   }
 
   retval = options_init_from_string(cf_defaults, cf, command, command_arg,