Fix for bug #35392: Delete all statement does not execute properly

after few delete statements

Problem: changing a file size might require that it must be 
unmapped beforehand.
  
Fix: unmap the file before changing its size.


mysql-test/r/temp_table.result:
  Fix for bug #35392: Delete all statement does not execute properly 
  after few delete statements
    - test result.
mysql-test/t/temp_table.test:
  Fix for bug #35392: Delete all statement does not execute properly 
  after few delete statements
    - test case.
storage/myisam/mi_delete_all.c:
  Fix for bug #35392: Delete all statement does not execute properly 
  after few delete statements
    - unmap file before changing its size as it's required 
      by SetEndOfFile() function (see my_chsize()).
    - as no other threads allowed to perform concurrent inserts 
      when delete_all is called, mmap_lock locking removed.

1 files changed, 14 insertions, 0 deletions

diff --git a/mysql-test/t/temp_table.test b/mysql-test/t/temp_table.test
index d1ad7ab8ffa..4ab8a982e63 100644
--- a/mysql-test/t/temp_table.test
+++ b/mysql-test/t/temp_table.test
@@ -191,3 +191,17 @@ truncate t1;
 insert into t1 values (42);
 select * from t1;
 drop table t1;
+
+#
+# Bug #35392: Delete all statement does not execute properly after 
+# few delete statements
+#
+CREATE TEMPORARY TABLE t1(a INT, b VARCHAR(20));
+INSERT INTO t1 VALUES(1, 'val1'), (2, 'val2'), (3, 'val3');
+DELETE FROM t1 WHERE a=1;
+SELECT count(*) FROM t1;
+DELETE FROM t1;
+SELECT * FROM t1;
+DROP TABLE t1;
+
+--echo End of 5.1 tests