Bug #13323

Select count(*) returned 2 on empty table where handler
used exact count


mysql-test/r/partition.result:
  New test case for Bug #13323
mysql-test/t/partition.test:
  New test case for Bug #13323
sql/ha_partition.cc:
  Fix for Bug #13323

mysql-test/r/partition.result

@@ -5,6 +5,9 @@ b int not null,
 c int not null,
 primary key(a,b))
 partition by key (a);
+select count(*) from t1;
+count(*)
+0
 drop table t1;
 CREATE TABLE t1 (
 a int not null,

mysql-test/t/partition.test

@@ -18,6 +18,11 @@ c int not null,
 primary key(a,b))
 partition by key (a);
 
+#
+# Bug 13323: Select count(*) on empty table returns 2
+#
+select count(*) from t1;
+
 drop table t1;
 #
 # Partition by key no partition, list of fields

sql/ha_partition.cc

@@ -81,6 +81,9 @@ static handlerton partition_hton = {
   NULL, /* recover */
   NULL, /* commit_by_xid */
   NULL, /* rollback_by_xid */
+  NULL,
+  NULL,
+  NULL,
   HTON_NO_FLAGS
 };
 
@@ -2305,9 +2308,13 @@ void ha_partition::info(uint flag)
       if (file->check_time > check_time)
 	check_time= file->check_time;
     } while (*(++file_array));
-    if (records < 2)
+    if (records < 2 &&
+        m_table_flags & HA_NOT_EXACT_COUNT)
       records= 2;
-    mean_rec_length= (ulong) (data_file_length / records);
+    if (records > 0)
+      mean_rec_length= (ulong) (data_file_length / records);
+    else
+      mean_rec_length= 1; //? What should we set here 
   }
   if (flag & HA_STATUS_CONST)
   {