1 files changed, 4 insertions, 1 deletions
diff --git a/sql/sql_parse.cc b/sql/sql_parse.cc
index 659926bdea3..4e84bc9d046 100644
--- a/sql/sql_parse.cc
+++ b/sql/sql_parse.cc
@@ -909,9 +909,12 @@ static int check_connection(THD *thd)
     Old clients send null-terminated string as password; new clients send
     the size (1 byte) + string (not null-terminated). Hence in case of empty
     password both send '\0'.
+
+    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.
   */
   uint passwd_len= thd->client_capabilities & CLIENT_SECURE_CONNECTION ?
-    *passwd++ : strlen(passwd);
+    (uchar)(*passwd++) : strlen(passwd);
   db= thd->client_capabilities & CLIENT_CONNECT_WITH_DB ?
     db + passwd_len + 1 : 0;
   uint db_len= db ? strlen(db) : 0;