BUG#23175 - MYISAM crash/repair failed during repair

Repair table could crash a server if there is not sufficient
memory (myisam_sort_buffer_size) to operate. Affects not only
repair, but also all statements that use create index by sort:
repair by sort, parallel repair, bulk insert.

Return an error if there is not sufficient memory to store at
least one key per BUFFPEK.

Also fixed memory leak if thr_find_all_keys returns an error.


myisam/sort.c:
  maxbuffer is number of BUFFPEK-s for repair. It is calculated
  as records / keys. keys is number of keys that can be stored
  in memory (myisam_sort_buffer_size). There must be sufficient
  memory to store both BUFFPEK-s and keys. It was checked
  correctly before this patch. However there is another
  requirement that wasn't checked: there must be sufficient
  memory for at least one key per BUFFPEK, otherwise repair
  by sort/parallel repair cannot operate.
  
  Return an error if there is not sufficient memory to store at
  least one key per BUFFPEK.
  
  Also fixed memory leak if thr_find_all_keys returns an error.
mysql-test/r/repair.result:
  A test case for BUG#23175.
mysql-test/t/repair.test:
  A test case for BUG#23175.

1 files changed, 28 insertions, 0 deletions

diff --git a/mysql-test/t/repair.test b/mysql-test/t/repair.test
index f086d5b0c2a..b192d5c0a64 100644
--- a/mysql-test/t/repair.test
+++ b/mysql-test/t/repair.test
@@ -45,4 +45,32 @@ SHOW INDEX FROM t1;
 SET myisam_repair_threads=@@global.myisam_repair_threads;
 DROP TABLE t1;
 
+#
+# BUG#23175 - MYISAM crash/repair failed during repair
+#
+CREATE TABLE t1(a CHAR(255), KEY(a));
+SET myisam_sort_buffer_size=4096;
+INSERT INTO t1 VALUES
+('0'),('0'),('0'),('0'),('0'),('0'),('0'),('0'),('0'),('0'),
+('0'),('0'),('0'),('0'),('0'),('0'),('0'),('0'),('0'),('0'),
+('0'),('0'),('0'),('0'),('0'),('0'),('0'),('0'),('0'),('0'),
+('0'),('0'),('0'),('0'),('0'),('0'),('0'),('0'),('0'),('0'),
+('0'),('0'),('0'),('0'),('0'),('0'),('0'),('0'),('0'),('0'),
+('0'),('0'),('0'),('0'),('0'),('0'),('0'),('0'),('0'),('0'),
+('0'),('0'),('0'),('0'),('0'),('0'),('0'),('0'),('0'),('0'),
+('0'),('0'),('0'),('0'),('0'),('0'),('0'),('0'),('0'),('0'),
+('0'),('0'),('0'),('0'),('0'),('0'),('0'),('0'),('0'),('0'),
+('0'),('0'),('0'),('0'),('0'),('0'),('0'),('0'),('0'),('0'),
+('0'),('0'),('0'),('0'),('0'),('0'),('0'),('0'),('0'),('0'),
+('0'),('0'),('0'),('0'),('0'),('0'),('0'),('0'),('0'),('0'),
+('0'),('0'),('0'),('0'),('0'),('0'),('0'),('0'),('0'),('0'),
+('0'),('0'),('0'),('0'),('0'),('0'),('0'),('0'),('0'),('0'),
+('0'),('0'),('0'),('0'),('0'),('0'),('0'),('0'),('0'),('0'),
+('0'),('0'),('0'),('0'),('0'),('0'),('0');
+SET myisam_repair_threads=2;
+REPAIR TABLE t1;
+SET myisam_repair_threads=@@global.myisam_repair_threads;
+SET myisam_sort_buffer_size=@@global.myisam_sort_buffer_size;
+DROP TABLE t1;
+
 # End of 4.1 tests