#4621 describe how the mysql-test program finds tests to run refs[t:4621]

git-svn-id: file:///svn/mysql/tests/mysql-test@41288 c7de825b-a66e-492c-adef-691d508d4ae1

mysql-test/README.tokudb

-The mysql tests for TokuDB consist of tests that are common to all MySQL distributions
-and tests that are specific to each MySQL distribtion. 
+The MySQL tests for TokuDB consists of two sets of tests.  
 
-The common mysql tests are stored in the svn:tokudb/mysql/tests/mysql-test directory.
+The tests that are common for all MySQL distributions can be found in the
+svn:tokudb/mysql/tests/mysql-test directory.
 
-The distribution specifc tests are stored with each MySQL distribution.  For example,
-tests specific to MySQL 5.1.61 can be found in the svn:tokudb/mysql.com/mysql-5.1.61/mysql-test
-directory.
+The tests that are specific to a particular distribution can be found in that
+distribution's mysql-test directory.  For example, tests that are specific to
+MySQL 5.5.21 are found in the svn:tokudb/mysql.com/mysql-5.5.21/mysql-test directory.
 
-We assemble tests from these places in the following order.  First, the common mysql tests 
-are checked out of the subversion repository.  Then, the distribution specific tests are 
-overlayed onto the common tests.  This allows a distribution specific test to replace the
-behaviour captured in a common test.  Please see the run.mysql.tests.bash script for
-an example of how this works.
+When we run tests on a particular MySQL distribution, we run the union of the common
+tests and the tests that are in that distributions mysql-test directory.  The union
+is formed by overlaying the common tests with the distribution specific tests.  
 
+Here is an example.  There are a bunch of alter table tests in that should be common
+to all MySQL distributions.  These tests are in the 
+svn:tokudb/mysql/tests/mysql-test/suite/tokudb.alter_table directory.
+However, the ai_di.test has behaviour that is different on MySQL 5.5 than previous 
+MySQL distributions.  There is another version of this test in the MySQL 5.5.21 source
+directory.  This version replaces the common test since it has the same test name.
 
+It is easy to disable a test.  Just add the test name to the "disabled.def" file in the
+test directory.