MDEV-6401 SET ROLE returning ERROR 1959 Invalid role specification for valid role

Use user's ip address when verifying privileges for SET ROLE (just like check_access() does)

mysql-test/suite/roles/ip-6401.result

+create role r1;
+create user foo@'127.0.0.1';
+grant r1 to foo@'127.0.0.1';
+show grants;
+Grants for foo@127.0.0.1
+GRANT r1 TO 'foo'@'127.0.0.1'
+GRANT USAGE ON *.* TO 'foo'@'127.0.0.1'
+set role r1;
+select * from information_schema.enabled_roles;
+ROLE_NAME
+r1
+drop user foo@'127.0.0.1';
+drop role r1;

mysql-test/suite/roles/ip-6401.test

+--source include/not_embedded.inc
+create role r1;
+create user foo@'127.0.0.1';
+grant r1 to foo@'127.0.0.1';
+
+--connect (con1,127.0.0.1,foo,,)
+show grants;
+set role r1;
+select * from information_schema.enabled_roles;
+
+connection default;
+drop user foo@'127.0.0.1';
+drop role r1;

sql/sql_acl.cc

@@ -300,7 +300,7 @@ class ACL_USER :public ACL_USER_BASE
 
   bool eq(const char *user2, const char *host2) { return !cmp(user2, host2); }
 
-  bool wild_eq(const char *user2, const char *host2, const char *ip2 = 0)
+  bool wild_eq(const char *user2, const char *host2, const char *ip2)
   {
     if (strcmp(safe_str(user.str), safe_str(user2)))
       return false;
@@ -1883,7 +1883,7 @@ int acl_check_setrole(THD *thd, char *rolename, ulonglong *access)
     acl_user= (ACL_USER *)acl_user_base;
     /* Yes! priv_user@host. Don't ask why - that's what check_access() does. */
     if (acl_user->wild_eq(thd->security_ctx->priv_user,
-                          thd->security_ctx->host))
+                          thd->security_ctx->host, thd->security_ctx->ip))
     {
       is_granted= TRUE;
       break;