select IF ( 1 = 0 , '<--- 17 CHAR --->',
                    '<### 17 CHAR ###>aaaaaaaaaaaaaaaaaaaaaaaa')
    as "my_column"
union select        'here is the union line';
# Here I get wrong output. The server must return:
# '<### 17 CHAR ###>aaaaaaaaaaaaaaaaaaaaaaaa'

# The bug seems to depend on the length of expr1 and the line caused by UNION
select IF ( 1 = 0 , '<------- 26 CHAR -------->',
                    '<####### 26 CHAR ########>aaaaaaaaaaaaaaa')
    as "my_column"
union        select 'here is the union line';
# Here I get wrong output. The server must return:
# '<## 16 CHAR ###>aaaaaaaaaaaaaaaaaaaaaaaaa'

# The bug disappears, when UNION is omitted
select IF ( 1 = 0 , '<--- 17 CHAR --->',
                    '<### 17 CHAR ###>aaaaaaaaaaaaaaaaaaaaaaaa')
    as "my_column";
# Here I get the expected output:
# '<### 17 CHAR ###>aaaaaaaaaaaaaaaaaaaaaaaa'

# The control flow function CASE + UNION give the expected output
SELECT CASE 2 WHEN 1 THEN '<--- 17 CHAR --->'
              WHEN 2 THEN '<### 17 CHAR ###>aaaaaaaaaaaaaaaaaaaaaaaa' END
    as "my_column"
union              select 'here is the union line';

###############################################################################
# My original test case slightly modified
set sql_mode='PIPES_AS_CONCAT';

let $my_errno= 1;
let $exp_val=  0;
eval select IF ( $my_errno = $exp_val , 'TEST-INFO: passed',
                'TEST-INFO: failed, wrong return code got:' || $my_errno
                || ' expected: ' || CAST($exp_val as CHAR)) as ""
union
select '';
# Must return:
# 'TEST-INFO: failed, wrong return code got:1 expected: 0'