Bug#28984: crasher on connect with out of range password length in \

	protocol

Fixed duplicated code, same as last commit.

One could send a malformed packet that caused the server to SEGV.  In 
recent versions of the password protocol, the client tells the server 
what length the ciphertext is (almost always 20).  If that length was
large enough to overflow a signed char, then the number would jump to 
very large after being casted to unsigned int.

Instead, cast the *passwd char to uchar.

sql/sql_parse.cc

@@ -1445,11 +1445,14 @@ bool dispatch_command(enum enum_server_command command, THD *thd,
       Old clients send null-terminated string ('\0' for empty string) for
       password.  New clients send the size (1 byte) + string (not null
       terminated, so also '\0' for empty string).
+
+      Cast *passwd to an unsigned char, so that it doesn't extend the sign
+      for *passwd > 127 and become 2**32-127 after casting to uint.
     */
     char db_buff[NAME_LEN+1];                 // buffer to store db in utf8 
     char *db= passwd;
     uint passwd_len= thd->client_capabilities & CLIENT_SECURE_CONNECTION ? 
-      *passwd++ : strlen(passwd);
+      (uchar)(*passwd++) : strlen(passwd);
     db+= passwd_len + 1;
 #ifndef EMBEDDED_LIBRARY
     /* Small check for incomming packet */