Restore creation of test databases and the anonymous user which

were accidentally removed during a previous rototill of this
code.  Fixes bug#27692.
  
While it can be argued we should strive to provide a 'secure by
default' installation, this happens to be the setup currently
documented in the manual as the default, so defer changes that
improve security out of the box to a co-ordinated effort later
on.
  
For now, make a note about the test databases and anonymous user
in mysql_install_db and recommend that mysql_secure_installation
be ran for users wishing to remove these defaults.

[..re-commit of previously lost change..]


scripts/mysql_system_tables_data.sql:
  Add anonymous accounts.
scripts/mysql_install_db.sh:
  Point users at the mysql_secure_installation script.
mysql-test/mysql-test-run.pl:
  Add a comment where removing anonymous users.

mysql-test/mysql-test-run.pl

@@ -3059,6 +3059,7 @@ sub install_db ($$) {
   mtr_appendfile_to_file("$path_sql_dir/fill_help_tables.sql",
 			 $bootstrap_sql_file);
 
+  # Remove anonymous users
   mtr_tofile($bootstrap_sql_file,
 	     "DELETE FROM mysql.user where user= '';");
 

scripts/mysql_install_db.sh

@@ -371,7 +371,16 @@ then
     echo "To do so, start the server, then issue the following commands:"
     echo "$bindir/mysqladmin -u root password 'new-password'"
     echo "$bindir/mysqladmin -u root -h $hostname password 'new-password'"
+    echo
+    echo "Alternatively you can run:"
+    echo "$bindir/mysql_secure_installation"
+    echo
+    echo "which will also give you the option of removing the test"
+    echo "databases and anonymous user created by default.  This is"
+    echo "strongly recommended for production servers."
+    echo
     echo "See the manual for more instructions."
+    echo
 
     if test "$in_rpm" -eq 0
     then

scripts/mysql_system_tables_data.sql

@@ -17,5 +17,7 @@ CREATE TEMPORARY TABLE tmp_user LIKE user;
 INSERT INTO tmp_user VALUES ('localhost','root','','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','','','','',0,0,0,0);
 REPLACE INTO tmp_user VALUES (@@hostname,'root','','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','','','','',0,0,0,0);
 REPLACE INTO tmp_user VALUES ('127.0.0.1','root','','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','','','','',0,0,0,0);
+INSERT INTO tmp_user (host,user) VALUES ('localhost','');
+INSERT INTO tmp_user (host,user) VALUES (@@hostname,'');
 INSERT INTO user SELECT * FROM tmp_user WHERE @had_user_table=0;
 DROP TABLE tmp_user;