Fix for Bug #1595 "mysqlbinlog can't read a password from the console".

Make mysqlbinlog prompt for the password if
mysqlbinlog -p
instead of printing the usage().
This makes mysqlbinlog behave like other clients, which is the reason
why we fix this in 3.23.
This new code was almost copied from mysqldump.
Note that before, one could use
mysqlbinlog -p pass
and now one must use
mysqlbinlog -ppass
(putting a space will ask for the password).

client/mysqlbinlog.cc

@@ -54,7 +54,7 @@ static struct option long_options[] =
   {"help", 	  no_argument, 		0, '?'},
   {"host", 	  required_argument,	0, 'h'},
   {"offset", 	  required_argument,	0, 'o'},
-  {"password",	  required_argument,	0, 'p'},
+  {"password",	  optional_argument,	0, 'p'},
   {"port", 	  required_argument,	0, 'P'},
   {"position",	  required_argument,	0, 'j'},
   {"result-file", required_argument,    0, 'r'},
@@ -71,7 +71,7 @@ static ulonglong offset = 0;
 static const char* host = "localhost";
 static int port = MYSQL_PORT;
 static const char* user = "test";
-static const char* pass = "";
+static char* pass = 0;
 static ulonglong position = 0;
 static bool use_remote = 0;
 static short binlog_flags = 0; 
@@ -84,6 +84,7 @@ static void dump_log_entries(const char* logname);
 static void dump_remote_file(NET* net, const char* fname);
 static void dump_remote_table(NET* net, const char* db, const char* table);
 static void die(const char* fmt, ...);
+static void cleanup();
 static MYSQL* safe_connect();
 
 
@@ -97,6 +98,11 @@ void sql_print_error(const char *format,...)
   va_end(args);
 }
 
+static void cleanup()
+{
+  my_free(pass,MYF(MY_ALLOW_ZERO_PTR));
+}
+
 static void die(const char* fmt, ...)
 {
   va_list args;
@@ -105,6 +111,7 @@ static void die(const char* fmt, ...)
   vfprintf(stderr, fmt, args);
   fprintf(stderr, "\n");
   va_end(args);
+  cleanup();
   exit(1);
 }
 
@@ -177,9 +184,10 @@ static void dump_remote_file(NET* net, const char* fname)
 static int parse_args(int *argc, char*** argv)
 {
   int c, opt_index = 0;
+  bool tty_password= 0;
 
   result_file = stdout;
-  while((c = getopt_long(*argc, *argv, "so:#::h:j:u:p:P:r:t:?V", long_options,
+  while((c = getopt_long(*argc, *argv, "so:#::h:j:u:p::P:r:t:?V", long_options,
 			 &opt_index)) != EOF)
   {
     switch(c)
@@ -213,7 +221,17 @@ static int parse_args(int *argc, char*** argv)
       
     case 'p':
       use_remote = 1;
-      pass = my_strdup(optarg, MYF(0));
+      if (optarg)
+      {
+	char *start=optarg;
+	my_free(pass,MYF(MY_ALLOW_ZERO_PTR));        
+	pass= my_strdup(optarg,MYF(MY_FAE));
+	while (*optarg) *optarg++= 'x';		/* Destroy argument */
+	if (*start)
+	  start[1]=0;				/* Cut length of argument */
+      }
+      else
+	tty_password=1;
       break;
 
     case 'r':
@@ -244,6 +262,8 @@ static int parse_args(int *argc, char*** argv)
 
   (*argc)-=optind;
   (*argv)+=optind;
+  if (tty_password)
+    pass= get_tty_password(NullS);
 
   return 0;
 }
@@ -457,6 +477,7 @@ int main(int argc, char** argv)
     my_fclose(result_file, MYF(0));
   if (use_remote)
     mysql_close(mysql);
+  cleanup();
   return 0;
 }