From bfdc09f4eb9954a3937728eb51bd9e7c2d927e14 Mon Sep 17 00:00:00 2001
From: ti-srebot <66930949+ti-srebot@users.noreply.github.com>
Date: Tue, 1 Sep 2020 17:32:52 +0800
Subject: [PATCH] executor: fix the bug: can not join if join keys are type
 bigint and type bit (#19032) (#19215)

Signed-off-by: ti-srebot <ti-srebot@pingcap.com>
---
 executor/join_test.go | 60 ++++++++++++++++++++++++++++++++++++-------
 util/codec/codec.go   | 14 +++++-----
 2 files changed, 57 insertions(+), 17 deletions(-)

diff --git a/executor/join_test.go b/executor/join_test.go
index 47c843d245e46..d6150933928e4 100644
--- a/executor/join_test.go
+++ b/executor/join_test.go
@@ -2171,16 +2171,58 @@ func (s *testSuite9) TestIssue18572_3(c *C) {
 	c.Assert(strings.Contains(err.Error(), "mockIndexHashJoinBuildErr"), IsTrue)
 }
 
-func (s *testSuite9) TestIssue19112(c *C) {
+func (s *testSuiteJoin3) TestIssue11896(c *C) {
 	tk := testkit.NewTestKitWithInit(c, s.store)
-	tk.MustExec("drop table if exists t1, t2")
-	tk.MustExec("create table t1 ( c_int int, c_decimal decimal(12, 6), key(c_int), unique key(c_decimal) )")
-	tk.MustExec("create table t2 like t1")
-	tk.MustExec("insert into t1 (c_int, c_decimal) values (1, 4.064000), (2, 0.257000), (3, 1.010000)")
-	tk.MustExec("insert into t2 (c_int, c_decimal) values (1, 4.064000), (3, 1.010000)")
-	tk.MustQuery("select /*+ HASH_JOIN(t1,t2) */  * from t1 join t2 on t1.c_decimal = t2.c_decimal order by t1.c_int").Check(testkit.Rows(
-		"1 4.064000 1 4.064000",
-		"3 1.010000 3 1.010000"))
+
+	// compare bigint to bit(64)
+	tk.MustExec("drop table if exists t")
+	tk.MustExec("drop table if exists t1")
+	tk.MustExec("create table t(c1 bigint)")
+	tk.MustExec("create table t1(c1 bit(64))")
+	tk.MustExec("insert into t value(1)")
+	tk.MustExec("insert into t1 value(1)")
+	tk.MustQuery("select * from t, t1 where t.c1 = t1.c1").Check(
+		testkit.Rows("1 \x00\x00\x00\x00\x00\x00\x00\x01"))
+
+	// compare int to bit(32)
+	tk.MustExec("drop table if exists t")
+	tk.MustExec("drop table if exists t1")
+	tk.MustExec("create table t(c1 int)")
+	tk.MustExec("create table t1(c1 bit(32))")
+	tk.MustExec("insert into t value(1)")
+	tk.MustExec("insert into t1 value(1)")
+	tk.MustQuery("select * from t, t1 where t.c1 = t1.c1").Check(
+		testkit.Rows("1 \x00\x00\x00\x01"))
+
+	// compare mediumint to bit(24)
+	tk.MustExec("drop table if exists t")
+	tk.MustExec("drop table if exists t1")
+	tk.MustExec("create table t(c1 mediumint)")
+	tk.MustExec("create table t1(c1 bit(24))")
+	tk.MustExec("insert into t value(1)")
+	tk.MustExec("insert into t1 value(1)")
+	tk.MustQuery("select * from t, t1 where t.c1 = t1.c1").Check(
+		testkit.Rows("1 \x00\x00\x01"))
+
+	// compare smallint to bit(16)
+	tk.MustExec("drop table if exists t")
+	tk.MustExec("drop table if exists t1")
+	tk.MustExec("create table t(c1 smallint)")
+	tk.MustExec("create table t1(c1 bit(16))")
+	tk.MustExec("insert into t value(1)")
+	tk.MustExec("insert into t1 value(1)")
+	tk.MustQuery("select * from t, t1 where t.c1 = t1.c1").Check(
+		testkit.Rows("1 \x00\x01"))
+
+	// compare tinyint to bit(8)
+	tk.MustExec("drop table if exists t")
+	tk.MustExec("drop table if exists t1")
+	tk.MustExec("create table t(c1 tinyint)")
+	tk.MustExec("create table t1(c1 bit(8))")
+	tk.MustExec("insert into t value(1)")
+	tk.MustExec("insert into t1 value(1)")
+	tk.MustQuery("select * from t, t1 where t.c1 = t1.c1").Check(
+		testkit.Rows("1 \x01"))
 }
 
 func (s *testSuiteJoin3) TestIssue19498(c *C) {
diff --git a/util/codec/codec.go b/util/codec/codec.go
index 3da99782cc386..597701b04bae3 100644
--- a/util/codec/codec.go
+++ b/util/codec/codec.go
@@ -300,11 +300,9 @@ func encodeHashChunkRowIdx(sc *stmtctx.StatementContext, row chunk.Row, tp *type
 	}
 	switch tp.Tp {
 	case mysql.TypeTiny, mysql.TypeShort, mysql.TypeInt24, mysql.TypeLong, mysql.TypeLonglong, mysql.TypeYear:
-		flag = varintFlag
-		if mysql.HasUnsignedFlag(tp.Flag) {
-			if integer := row.GetInt64(idx); integer < 0 {
-				flag = uvarintFlag
-			}
+		flag = uvarintFlag
+		if !mysql.HasUnsignedFlag(tp.Flag) && row.GetInt64(idx) < 0 {
+			flag = varintFlag
 		}
 		b = row.GetRaw(idx)
 	case mysql.TypeFloat:
@@ -406,9 +404,9 @@ func HashChunkSelected(sc *stmtctx.StatementContext, h []hash.Hash64, chk *chunk
 				buf[0], b = NilFlag, nil
 				isNull[i] = true
 			} else {
-				buf[0] = varintFlag
-				if mysql.HasUnsignedFlag(tp.Flag) && v < 0 {
-					buf[0] = uvarintFlag
+				buf[0] = uvarintFlag
+				if !mysql.HasUnsignedFlag(tp.Flag) && v < 0 {
+					buf[0] = varintFlag
 				}
 				b = column.GetRaw(i)
 			}