From b2a6e97aac6e967b8d1ade8ba1aae4074935b914 Mon Sep 17 00:00:00 2001
From: Alexander Peresypkin <7003484@gmail.com>
Date: Sun, 4 Aug 2019 17:14:06 +0200
Subject: [PATCH] Fix cast unsigned. Version 8.0

https://bugs.mysql.com/bug.php?id=95954
---
 mysql-test/r/cast_unsigned.result | 19 +++++++++++++++++++
 mysql-test/t/cast_unsigned.test   | 14 ++++++++++++++
 sql/item_func.cc                  |  2 +-
 3 files changed, 34 insertions(+), 1 deletion(-)
 create mode 100644 mysql-test/r/cast_unsigned.result
 create mode 100644 mysql-test/t/cast_unsigned.test

diff --git a/mysql-test/r/cast_unsigned.result b/mysql-test/r/cast_unsigned.result
new file mode 100644
index 00000000000..53d56ae0864
--- /dev/null
+++ b/mysql-test/r/cast_unsigned.result
@@ -0,0 +1,19 @@
+DROP TABLE IF EXISTS t0;
+CREATE TABLE t0(c0 BIGINT UNSIGNED);
+INSERT INTO t0(c0) VALUES(NULL);
+SELECT * FROM t0 WHERE CAST(COALESCE(t0.c0, -1) AS UNSIGNED);
+c0
+NULL
+SELECT * FROM t0 WHERE CAST(IFNULL(t0.c0, -1) AS UNSIGNED);
+c0
+NULL
+SELECT CAST(COALESCE(t0.c0, -1) AS UNSIGNED) IS TRUE FROM t0;
+CAST(COALESCE(t0.c0, -1) AS UNSIGNED) IS TRUE
+1
+SELECT CAST(COALESCE(t0.c0, -1) AS UNSIGNED) FROM t0;
+CAST(COALESCE(t0.c0, -1) AS UNSIGNED)
+18446744073709551615
+DROP TABLE t0;
+SELECT CAST(-1.1 AS UNSIGNED);
+CAST(-1.1 AS UNSIGNED)
+18446744073709551615
diff --git a/mysql-test/t/cast_unsigned.test b/mysql-test/t/cast_unsigned.test
new file mode 100644
index 00000000000..3a909bb54ae
--- /dev/null
+++ b/mysql-test/t/cast_unsigned.test
@@ -0,0 +1,14 @@
+--disable_warnings
+DROP TABLE IF EXISTS t0;
+--enable_warnings
+
+CREATE TABLE t0(c0 BIGINT UNSIGNED);
+INSERT INTO t0(c0) VALUES(NULL);
+SELECT * FROM t0 WHERE CAST(COALESCE(t0.c0, -1) AS UNSIGNED);
+SELECT * FROM t0 WHERE CAST(IFNULL(t0.c0, -1) AS UNSIGNED);
+SELECT CAST(COALESCE(t0.c0, -1) AS UNSIGNED) IS TRUE FROM t0;
+SELECT CAST(COALESCE(t0.c0, -1) AS UNSIGNED) FROM t0;
+
+DROP TABLE t0;
+
+SELECT CAST(-1.1 AS UNSIGNED);
diff --git a/sql/item_func.cc b/sql/item_func.cc
index 08daf8681ab..352b584530c 100644
--- a/sql/item_func.cc
+++ b/sql/item_func.cc
@@ -1577,7 +1577,7 @@ longlong Item_typecast_unsigned::val_int() {
   if (args[0]->cast_to_int_type() == DECIMAL_RESULT) {
     my_decimal tmp, *dec = args[0]->val_decimal(&tmp);
     if (!(null_value = args[0]->null_value))
-      my_decimal2int(E_DEC_FATAL_ERROR, dec, 1, &value);
+      my_decimal2int(E_DEC_FATAL_ERROR, dec, args[0]->unsigned_flag, &value);
     else
       value = 0;
     return value;