From 2b35fee8ab4bce7c40b95cb6b3b3593bd0960546 Mon Sep 17 00:00:00 2001 From: unknown Date: Mon, 6 Nov 2006 17:13:19 -0500 Subject: Bug#23411: ... MOD-ing zero returns strange result The Item_func_mod objects never had maybe_null set, so users had no reason to expect that they can be NULL, and may therefore deduce wrong results. Now, set maybe_null. mysql-test/r/func_test.result: Verify that the predictions are true. mysql-test/t/func_test.test: Verify that the predictions are true. sql/item_func.cc: MOD functions may be NULL. --- mysql-test/t/func_test.test | 32 ++++++++++++++++++++++++++++++++ 1 file changed, 32 insertions(+) (limited to 'mysql-test/t/func_test.test') diff --git a/mysql-test/t/func_test.test b/mysql-test/t/func_test.test index 2ad64b6c5a6..99519b54ca6 100644 --- a/mysql-test/t/func_test.test +++ b/mysql-test/t/func_test.test @@ -108,4 +108,36 @@ select 5.1 mod 3, 5.1 mod -3, -5.1 mod 3, -5.1 mod -3; select 5 mod 3, 5 mod -3, -5 mod 3, -5 mod -3; +# +# Bug#23411: The "%" (MOD) operator is not documented; MOD-ing zero returns strange result +# Manual: "Division by zero produces a NULL result" +# +select (12%0) <=> null as '1'; +select (12%0) is null as '1'; +select 12%0 as 'NULL'; +select 12%2 as '0'; +select 12%NULL as 'NULL'; +select 12 % null as 'NULL'; +select null % 12 as 'NULL'; +select null % 0 as 'NULL'; +select 0 % null as 'NULL'; +select null % null as 'NULL'; + +select (12 mod 0) <=> null as '1'; +select (12 mod 0) is null as '1'; +select 12 mod 0 as 'NULL'; +select 12 mod 2 as '0'; +select 12 mod null as 'NULL'; +select null mod 12 as 'NULL'; +select null mod 0 as 'NULL'; +select 0 mod null as 'NULL'; +select null mod null as 'NULL'; + +select mod(12.0, 0) as 'NULL'; +select mod(12, 0.0) as 'NULL'; +select mod(12, NULL) as 'NULL'; +select mod(12.0, NULL) as 'NULL'; +select mod(NULL, 2) as 'NULL'; +select mod(NULL, 2.0) as 'NULL'; + # End of 4.1 tests -- cgit v1.2.1