Bug #39987 main.partition_not_windows fails under debug build

Description:
Regression from Bug#32167

With a debug build, main.partition_not_windows dies with:

mysqltest: At line 40: query 'ALTER TABLE t1 REORGANIZE PARTITION p0 INTO
(partition p1 VALUES LESS THAN (1) $data_directory $inx_directory
(SUBPARTITION subpart10, SUBPARTITION subpart11),
partition p2 VALUES LESS THAN (2) $data_directory $inx_directory
(SUBPARTITION subpart20, SUBPARTITION subpart21))' failed: 1030: Got error 140 from storage engine

How to repeat:
BUILD/compile-pentium64-valgrind-max
mysql-test-run main.partition_not_windows

Suggested fix:
mysqld.cc:

@@ -7473,6 +7487,10 @@ static void mysql_init_variables(void)
   /* Things reset to zero */
   opt_skip_slave_start= opt_reckless_slave = 0;
   mysql_home[0]= pidfile_name[0]= log_error_file[0]= 0;
+#if defined(HAVE_REALPATH) && !defined(HAVE_purify) && !defined(HAVE_BROKEN_REALPATH)
+  /*  We can only test for sub paths if my_symlink.c is using realpath */
+  myisam_test_invalid_symlink= test_if_data_home_dir;
+#endif

This is a duplicate of bug#39102.

Pushed into 6.0.8-alpha  (revid:monty@mysql.com-20081012100952-h39szt1kgq6j0tj4) (version source revid:guilhem@mysql.com-20081020191322-i0e65e3k8044kkce) (pib:5)

Duplicate of bug#39102. (pushed into the 51-bugteam)