Bug#27029 alter table ... enable keys crashes mysqld on large table

- When creating an index for the sort, the number of rows plus 1 is used 
to allocate a buffer.  In this test case, the number of rows 4294967295 
is the max value of an unsigned integer, so when 1 was added to it, a 
buffer of size 0 was allocated causing the crash.
- Create new test suite for this bug's test suite as per QA.

myisam/sort.c

@@ -138,8 +138,9 @@ int _create_index_by_sort(MI_SORT_PARAM *info,my_bool no_messages,
 
   while (memavl >= MIN_SORT_MEMORY)
   {
-    if ((my_off_t) (records+1)*(sort_length+sizeof(char*)) <=
-	(my_off_t) memavl)
+    if ((records < UINT_MAX32) && 
+       ((my_off_t) (records + 1) * 
+        (sort_length + sizeof(char*)) <= (my_off_t) memavl))
       keys= records+1;
     else
       do

mysql-test/suite/large_tests/README.TXT

+large_test suite
+================
+
+Iggy Galarza 07/20/07
+---------------------
+
+This test suite should include any test that requires:
+1. Longer than the default timeout to complete.
+2. A considerable amount of disk space.
+
+These tests can be completed with the following command:
+
+mysql-test-run.pl --suite=large_tests --big-test --suite-timeout=6360 --testcase-timeout=795

mysql-test/suite/large_tests/r/alter_table.result

+drop table if exists t1;
+create table `t1` (`c1` tinyint unsigned not null, key `c1` (`c1`)) 
+engine=myisam default charset=utf8;
+alter table `t1` disable keys;
+insert into t1 values (1),(2),(3),(4);
+insert into t1 select * from t1;
+insert into t1 select * from t1;
+insert into t1 select * from t1;
+insert into t1 select * from t1;
+insert into t1 select * from t1;
+insert into t1 select * from t1;
+insert into t1 select * from t1;
+insert into t1 select * from t1;
+insert into t1 select * from t1;
+insert into t1 select * from t1;
+insert into t1 select * from t1;
+insert into t1 select * from t1;
+insert into t1 select * from t1;
+insert into t1 select * from t1;
+insert into t1 select * from t1;
+insert into t1 select * from t1;
+insert into t1 select * from t1;
+insert into t1 select * from t1;
+insert into t1 select * from t1;
+insert into t1 select * from t1;
+insert into t1 select * from t1;
+insert into t1 select * from t1;
+insert into t1 select * from t1;
+insert into t1 select * from t1;
+insert into t1 select * from t1;
+insert into t1 select * from t1;
+insert into t1 select * from t1;
+insert into t1 select * from t1;
+insert into t1 select * from t1;
+insert into t1 select * from t1 limit 2147483647;
+alter table t1 enable keys;
+drop table t1;

mysql-test/suite/large_tests/t/alter_table.test

+# The test for bug#27029 requires about 8 hours and 20 minutes on my
+# fastest machine.  This test requires at least 60 GB of disk space.
+--source include/big_test.inc
+
+#
+# Bug#27029 alter table ... enable keys crashes mysqld on large table
+#
+--disable_warnings
+drop table if exists t1;
+--enable_warnings
+
+create table `t1` (`c1` tinyint unsigned not null, key `c1` (`c1`)) 
+engine=myisam default charset=utf8;
+alter table `t1` disable keys;
+insert into t1 values (1),(2),(3),(4);
+insert into t1 select * from t1;
+insert into t1 select * from t1;
+insert into t1 select * from t1;
+insert into t1 select * from t1;
+insert into t1 select * from t1;
+insert into t1 select * from t1;
+insert into t1 select * from t1;
+insert into t1 select * from t1;
+insert into t1 select * from t1;
+insert into t1 select * from t1;
+insert into t1 select * from t1;
+insert into t1 select * from t1;
+insert into t1 select * from t1;
+insert into t1 select * from t1;
+insert into t1 select * from t1;
+insert into t1 select * from t1;
+insert into t1 select * from t1;
+insert into t1 select * from t1;
+insert into t1 select * from t1;
+insert into t1 select * from t1;
+insert into t1 select * from t1;
+insert into t1 select * from t1;
+insert into t1 select * from t1;
+insert into t1 select * from t1;
+insert into t1 select * from t1;
+insert into t1 select * from t1;
+insert into t1 select * from t1;
+insert into t1 select * from t1;
+insert into t1 select * from t1;
+insert into t1 select * from t1 limit 2147483647; #Insert 4294967295 rows.
+alter table t1 enable keys;
+drop table t1;