BUG#51307 - widespread corruption with partitions and

            insert...select

Queries following bulk insert into an empty MyISAM table
may break it. This was pure MyISAM problem.

When bulk insert into an empty table is complete, MyISAM
may want to enable indexes via repair by sort. If repair
by sort fails (e.g. insufficient buffer), MyISAM failover
to repair with key cache, requesting repair of data file.

Repair of data file performs data file substitution. This
means that current table instance will point to new data
file. Other cached table instances are still pointing to
an old, deleted data file.

This is fixed by not requesting repair of data file
during enable indexes.

Explicit REPAIR is not affected, since it flushes all
table instances.

mysql-test/r/myisam.result:
  A test case for BUG#51307.
mysql-test/t/myisam.test:
  A test case for BUG#51307.
storage/myisam/ha_myisam.cc:
  When enabling indexes do not attempt to repair data file.

1 files changed, 11 insertions, 3 deletions

diff --git a/storage/myisam/ha_myisam.cc b/storage/myisam/ha_myisam.cc
index 9c913b4f14d..12557b75cc1 100644
--- a/storage/myisam/ha_myisam.cc
+++ b/storage/myisam/ha_myisam.cc
@@ -1448,9 +1448,17 @@ int ha_myisam::enable_indexes(uint mode)
     {
       sql_print_warning("Warning: Enabling keys got errno %d on %s.%s, retrying",
                         my_errno, param.db_name, param.table_name);
-      /* Repairing by sort failed. Now try standard repair method. */
-      param.testflag&= ~(T_REP_BY_SORT | T_QUICK);
-      error= (repair(thd,param,0) != HA_ADMIN_OK);
+      /*
+        Repairing by sort failed. Now try standard repair method.
+        Still we want to fix only index file. If data file corruption
+        was detected (T_RETRY_WITHOUT_QUICK), we shouldn't do much here.
+        Let implicit repair do this job.
+      */
+      if (!(param.testflag & T_RETRY_WITHOUT_QUICK))
+      {
+        param.testflag&= ~T_REP_BY_SORT;
+        error= (repair(thd,param,0) != HA_ADMIN_OK);
+      }
       /*
         If the standard repair succeeded, clear all error messages which
         might have been set by the first repair. They can still be seen