DESCRIPTION

===========
When doing an upgrade, you execute mysql_upgrade. If
mysql_upgrade fails to connect or it connects with a user
without the proper privileges, it will return the error:

    FATAL ERROR: Upgrade failed

which is not very informative.

ANALYSIS
========

In main() and check_version_match(), the condition for
errors are clubbed together and throw the same error msg.
The functions need to be splitted up and the corresponding
error msgs have to be displayed.

FIX
===
Splitted the functions and added the specific error msg.

client/mysql_upgrade.c

 /*
-   Copyright (c) 2006, 2013, Oracle and/or its affiliates. All rights reserved.
+   Copyright (c) 2006, 2015, Oracle and/or its affiliates. All rights reserved.
 
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
@@ -862,10 +862,17 @@ static int check_version_match(void)
   if (init_dynamic_string(&ds_version, NULL, NAME_CHAR_LEN, NAME_CHAR_LEN))
     die("Out of memory");
 
-  if (run_query("show variables like 'version'",
-                &ds_version, FALSE) ||
-      extract_variable_from_show(&ds_version, version_str))
+
+  if (run_query("show variables like 'version'", &ds_version, FALSE))
   {
+    fprintf(stderr, "Error: Failed while fetching Server version! Could be"
+            " due to unauthorized access.\n");
+    dynstr_free(&ds_version);
+    return 1;                                   /* Query failed */
+  }
+  if (extract_variable_from_show(&ds_version, version_str))
+  {
+    fprintf(stderr, "Error: Failed while extracting Server version!\n");
     dynstr_free(&ds_version);
     return 1;                                   /* Query failed */
   }
@@ -955,15 +962,20 @@ int main(int argc, char **argv)
   /*
     Run "mysqlcheck" and "mysql_fix_privilege_tables.sql"
   */
-  if ((!opt_systables_only &&
-       (run_mysqlcheck_fixnames() || run_mysqlcheck_upgrade())) ||
-      run_sql_fix_privilege_tables())
+  if (!opt_systables_only)
   {
-    /*
-      The upgrade failed to complete in some way or another,
-      significant error message should have been printed to the screen
-    */
-    die("Upgrade failed" );
+    if (run_mysqlcheck_fixnames())
+      die("Error during call to mysql_check for fixing the db/tables names.");
+
+    if (run_mysqlcheck_upgrade())
+      die("Error during call to mysql_check for upgrading the tables names.");
+  }
+
+  if (run_sql_fix_privilege_tables())
+  {
+    /* Specific error msg (if present) would be printed in the function call
+     * above */
+    die("Upgrade failed");
   }
   verbose("OK");
 

mysql-test/r/mysql_upgrade.result

@@ -86,7 +86,7 @@ mysql.user                                         OK
 DROP USER mysqltest1@'%';
 Run mysql_upgrade with a non existing server socket
 mysqlcheck: Got error: 2005: Unknown MySQL server host 'not_existing_host' (errno) when trying to connect
-FATAL ERROR: Upgrade failed
+FATAL ERROR: Error during call to mysql_check for fixing the db/tables names.
 set GLOBAL sql_mode='STRICT_ALL_TABLES,ANSI_QUOTES,NO_ZERO_DATE';
 mtr.global_suppressions                            OK
 mtr.test_suppressions                              OK
@@ -226,4 +226,10 @@ mysql.time_zone_name                               OK
 mysql.time_zone_transition                         OK
 mysql.time_zone_transition_type                    OK
 mysql.user                                         OK
+#
+# Bug #21489398: MYSQL_UPGRADE: FATAL ERROR: UPGRADE FAILED - IMPROVE ERROR
+#
+Run mysql_upgrade with unauthorized access
+Error: Failed while fetching Server version! Could be due to unauthorized access.
+FATAL ERROR: Upgrade failed
 End of tests

mysql-test/t/mysql_upgrade.test

@@ -124,4 +124,13 @@ let $MYSQLD_DATADIR= `select @@datadir`;
 # so the following command should never fail.
 --remove_file $MYSQLD_DATADIR/mysql_upgrade_info
 
+
+--echo #
+--echo # Bug #21489398: MYSQL_UPGRADE: FATAL ERROR: UPGRADE FAILED - IMPROVE ERROR
+--echo #
+
+--echo Run mysql_upgrade with unauthorized access
+--error 1
+--exec $MYSQL_UPGRADE --skip-verbose --user=root --password=wrong_password 2>&1
+
 --echo End of tests