Allow more then one --conf-file on the command line.

man/dnsmasq.8

@@ -1942,8 +1942,9 @@ cannot be lower than 1025 unless dnsmasq is running as root. The number
 of concurrent TFTP connections is limited by the size of the port range. 
 .TP  
 .B \-C, --conf-file=<file>
-Specify a different configuration file. The \fB--conf-file\fP option is also allowed in
+Specify a configuration file. The presence of this option stops dnsmasq from reading the default configuration
-configuration files, to include multiple configuration files. A
+file (normally /etc/dnsmasq.conf). Multiple files may be specified by repeating the option
+either on the command line or in configuration files. A
 filename of "-" causes dnsmasq to read configuration from stdin.
 .TP
 .B \-7, --conf-dir=<directory>[,<file-extension>......],

src/option.c

@@ -5012,9 +5012,14 @@ void read_opts(int argc, char **argv, char *compile_opts)
         }
       else if (option == 'C')
 	{
-          if (conffile)
+          if (!conffile)
-            free(conffile);
 	    conffile = opt_string_alloc(arg);
+	  else
+	    {
+	      char *extra = opt_string_alloc(arg);
+	      one_file(extra, 0);
+	      free(extra);
+	    }
 	}
       else
 	{