Bug #20924: CAST(expr as UNSIGNED) returns SIGNED value when used in various functions

- Honor unsigned_flag in the corresponding functions
- Use compare_int_signed_unsigned()/compare_int_unsigned_signed() instead of explicit comparison in GREATEST() and LEAST()


mysql-test/r/case.result:
  Added test case for bug #20924
mysql-test/r/func_if.result:
  Added test case for bug #20924
mysql-test/r/func_test.result:
  Added test case for bug #20924
mysql-test/r/user_var.result:
  Added test case for bug #20924
mysql-test/t/case.test:
  Added test case for bug #20924
mysql-test/t/func_if.test:
  Added test case for bug #20924
mysql-test/t/func_test.test:
  Added test case for bug #20924
mysql-test/t/user_var.test:
  Added test case for bug #20924
sql/item_cmpfunc.cc:
  Bug #20924: CAST(expr as UNSIGNED) returns SIGNED value when used in various functions
  
  - Moved some code out of Arg_comparator to external functions to be reused in Item_func_min_max
  - Fixed IFNULL(), IF(), CASE() and COALESCE()
sql/item_cmpfunc.h:
  Bug #20924: CAST(expr as UNSIGNED) returns SIGNED value when used in various functions
  
  - Moved some code out of Arg_comparator to external functions to be reused in Item_func_min_max
sql/item_func.cc:
  Bug #20924: CAST(expr as UNSIGNED) returns SIGNED value when used in various functions
  
  Fixed LEAST(), GREATEST() and "SET @a=..." parts
sql/item_func.h:
  Bug #20924: CAST(expr as UNSIGNED) returns SIGNED value when used in various functions
  
  Fixed "SET @a=..." part
sql/sql_class.h:
  Bug #20924: CAST(expr as UNSIGNED) returns SIGNED value when used in various functions
  
  Fixed "SET @a=..." part

4 files changed, 28 insertions, 0 deletions

diff --git a/mysql-test/t/case.test b/mysql-test/t/case.test
index fd1b6e5247f..b868ae12b69 100644
--- a/mysql-test/t/case.test
+++ b/mysql-test/t/case.test
@@ -130,4 +130,10 @@ select min(a), min(case when 1=1 then a else NULL end),
 from t1 where b=3 group by b;
 drop table t1;
 
+#
+# Bug #20924: UNSIGNED values in CASE and COALESCE are treated as SIGNED
+#
+SELECT CASE 1 WHEN 1 THEN 18446744073709551615 ELSE 1 END;
+SELECT COALESCE(18446744073709551615);
+
 # End of 4.1 tests
diff --git a/mysql-test/t/func_if.test b/mysql-test/t/func_if.test
index 5756793c673..17117b07437 100644
--- a/mysql-test/t/func_if.test
+++ b/mysql-test/t/func_if.test
@@ -73,4 +73,14 @@ SELECT a, NULLIF(a,'') FROM t1 WHERE NULLIF(a,'') IS NULL;
 
 DROP TABLE t1;
 
+#
+# Bug #20924: UNSIGNED values in IF() are treated as SIGNED
+#
+SELECT IF(1 != 0, 18446744073709551615, 1);
+
+#
+# Bug #20924: UNSIGNED values in IFNULL() are treated as SIGNED
+#
+SELECT IFNULL(NULL, 18446744073709551615);
+
 # End of 4.1 tests
diff --git a/mysql-test/t/func_test.test b/mysql-test/t/func_test.test
index 2ad64b6c5a6..631639c7a74 100644
--- a/mysql-test/t/func_test.test
+++ b/mysql-test/t/func_test.test
@@ -108,4 +108,10 @@ 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 #20924: UNSIGNED values in GREATEST() and LEAST() are treated as SIGNED
+#
+SELECT GREATEST(1, 18446744073709551615);
+SELECT LEAST(1, 18446744073709551615);
+
 # End of 4.1 tests
diff --git a/mysql-test/t/user_var.test b/mysql-test/t/user_var.test
index 7691a574a2a..810d5e96da5 100644
--- a/mysql-test/t/user_var.test
+++ b/mysql-test/t/user_var.test
@@ -141,4 +141,10 @@ select @@global.version;
 --replace_column 1 #
 select @@session.VERSION;
 
+#
+# Bug #20924 SET on a user variable saves UNSIGNED as SIGNED
+#
+set @a=18446744073709551615;
+select @a;
+
 # End of 4.1 tests