Bug #31887: DML Select statement not returning same results

when executed in version 5

Zero fill is a field attribute only. So we can't always 
propagate  constants for zerofill fields : the values and 
expression results don't have that flag.

Fixed by converting the const value to a string and 
using that in const propagation when the context allows it. 
Disable const propagation for fields with ZEROFILL flag in
all the other cases.


mysql-test/r/compare.result:
  Bug #31887: test case
mysql-test/t/compare.test:
  Bug #31887: test case
sql/item.cc:
  Bug #31887: If the context allows conversion
  of an int constant to a zero-filled string constant
  put the string constant instead of the int constant
  when doing const propagation
sql/mysql_priv.h:
  Bug #31887: a macro to get all the Field_num
  descendant fields.

1 files changed, 31 insertions, 0 deletions

diff --git a/mysql-test/t/compare.test b/mysql-test/t/compare.test
index 337035a8095..8863ed825c2 100644
--- a/mysql-test/t/compare.test
+++ b/mysql-test/t/compare.test
@@ -46,3 +46,34 @@ insert into t1 values (0x01,0x01);
 select * from t1 where a=b;
 select * from t1 where a=b and b=0x01;
 drop table if exists t1;
+
+#
+# Bug #31887: DML Select statement not returning same results when executed
+# in version 5
+#
+
+CREATE TABLE  t1 (b int(2) zerofill, c int(2) zerofill);
+INSERT INTO t1 (b,c) VALUES (1,2), (1,1), (2,2);
+
+SELECT CONCAT(b,c), CONCAT(b,c) = '0101' FROM t1;
+
+EXPLAIN EXTENDED SELECT b,c FROM t1 WHERE b = 1 AND CONCAT(b,c) = '0101';
+SELECT b,c FROM t1 WHERE b = 1 AND CONCAT(b,c) = '0101';
+
+CREATE TABLE t2 (a int);
+INSERT INTO t2 VALUES (1),(2);
+
+SELECT a, 
+  (SELECT COUNT(*) FROM t1 
+   WHERE b = t2.a AND CONCAT(b,c) = CONCAT('0',t2.a,'01')) x 
+FROM t2 ORDER BY a;
+
+EXPLAIN EXTENDED 
+SELECT a, 
+  (SELECT COUNT(*) FROM t1 
+   WHERE b = t2.a AND CONCAT(b,c) = CONCAT('0',t2.a,'01')) x 
+FROM t2 ORDER BY a;
+
+DROP TABLE t1,t2;
+
+--echo End of 5.0 tests