MDEV-22966 Server crashes or hangs with SET ROLE when started with skip-grant-tables

mysql-test/r/skip_grants.result

@@ -99,3 +99,11 @@ Acl_users	0
 #
 # End of 10.1 tests
 #
+#
+# MDEV-22966 Server crashes or hangs with SET ROLE when started with skip-grant-tables
+#
+set role x;
+ERROR HY000: The MariaDB server is running with the --skip-grant-tables option so it cannot execute this statement
+#
+# End of 10.2 tests
+#

mysql-test/t/skip_grants.test

@@ -128,3 +128,14 @@ show global status like 'Acl%';
 --echo #
 --echo # End of 10.1 tests
 --echo #
+
+--echo #
+--echo # MDEV-22966 Server crashes or hangs with SET ROLE when started with skip-grant-tables
+--echo #
+
+--error ER_OPTION_PREVENTS_STATEMENT
+set role x;
+
+--echo #
+--echo # End of 10.2 tests
+--echo #

sql/sql_acl.cc

@@ -2770,6 +2770,12 @@ static int check_user_can_set_role(THD *thd, const char *user, const char *host,
 
 int acl_check_setrole(THD *thd, char *rolename, ulonglong *access)
 {
+  if (!initialized)
+  {
+    my_error(ER_OPTION_PREVENTS_STATEMENT, MYF(0), "--skip-grant-tables");
+    return 1;
+  }
+
   return check_user_can_set_role(thd, thd->security_ctx->priv_user,
            thd->security_ctx->host, thd->security_ctx->ip, rolename, access);
 }