Bug#40465: mysqldump.test does no checking of dump or restore.

Created new .test file - mysqldump_restore that does this for a limited number
of basic cases.
Created new .inc file - mysqldump.inc - renames original table and uses mysqldump
output to recreate the table, then uses diff_tables.inc to compare the two tables.
Backported include/diff_tables.inc to facilitate this testing.

mysql-test/include/mysqldump.inc

@@ -0,0 +1,41 @@
+################################################################################
+# mysqldump.inc
+# SUMMARY: include file to facilitate testing the quality of mysqldump output
+# INPUTS:  Two variables:
+#          $table_name - the name of the table that was dumped
+#          $mysqldumpfile - the name of the file that captured mysqldump output
+# OUTPUTS: minor echo data:
+#          We 'echo' some stage information to the .result file:
+#          'altering original table', 'restoring from dumpfile', 'comparing'
+# OTHER FILES:  We use include/diff_tables.inc to compare the original, renamed
+#               table with the 'restored' one. 
+# DESCRIPTION: This file works by being fed the name of the original table
+#              and a mysqldump output file.  The original table is then renamed
+#              to <table_name>_orig, the mysqldump file is used to recreate the
+#              table, then diff_tables.inc is called to compare them.
+# LIMITATIONS:  Does *NOT* work with xml output!
+# AUTHOR: pcrews
+# LAST CHANGE: 2009-05-21 
+# PURPOSE: Bug#40465: mysqldump.test does no checking of dump or restore
+################################################################################
+
+--echo # Begin testing mysqldump output + restore
+--echo # Create 'original table name - <table>_orig
+# NOTE: We use SET then let as query_get_value has issues with the extra commas
+#       used in the CONCAT statement.  
+eval SET @orig_table_name = CONCAT('$table_name', '_orig');
+let $orig_table_name = query_get_value(SELECT @orig_table_name,@orig_table_name,1);
+--echo # Rename original table
+eval ALTER TABLE $table_name RENAME to $orig_table_name;
+--echo # Recreate table from mysqldump output
+--exec $MYSQL test < $mysqldumpfile
+--echo # Compare original and recreated tables
+--echo # Recreated table: $table_name
+--echo # Original table: $orig_table_name
+let $diff_table_1 = $table_name;
+let $diff_table_2 = $orig_table_name;
+--source include/diff_tables.inc
+--echo # Cleanup
+--remove_file $mysqldumpfile
+eval DROP TABLE $table_name, $orig_table_name;
+