This is a patch for bug#41569.

"mysql_upgrade (ver 5.1) add 3 fields to mysql.proc table but does
not set values".
            
mysql_upgrade (ver 5.1) adds 3 fields (character_set_client, 
collation_connection and db_collation) to the mysql.proc table, but 
does not set any values. When we run stored procedures, which were 
created with mysql 5.0, a warning is logged into the error log.
            
The solution to this is for mysql_upgrade to set default best guess
values for these fields. A warning is also written during upgrade, to
make the user aware that default values are set.

client/mysql_upgrade.c

@@ -778,6 +778,10 @@ static int run_sql_fix_privilege_tables(void)
         found_real_errors++;
         print_line(line);
       }
+      else if (strncmp(line, "WARNING", 7) == 0)
+      {
+        print_line(line);
+      }
     } while ((line= get_line(line)) && *line);
   }