From 5c707ecf733c5f366e62a70b88e3724affc36f44 Mon Sep 17 00:00:00 2001
From: Zejun Li <bobotu@users.noreply.github.com>
Date: Tue, 25 Apr 2017 22:41:14 +0800
Subject: [PATCH] ddl, util/types: make converter correctly convert string to
 hex or bit. (#3115)

---
 ddl/ddl_api.go             |  7 +++++++
 ddl/ddl_db_test.go         | 18 ++++++++++++++++++
 util/types/bit.go          | 31 +++++++++++++++++++++++++++++++
 util/types/bit_test.go     |  4 ++++
 util/types/convert_test.go |  5 +++--
 util/types/datum.go        | 12 +++++++++++-
 6 files changed, 74 insertions(+), 3 deletions(-)

diff --git a/ddl/ddl_api.go b/ddl/ddl_api.go
index 21cc9bc47056a..35a196993afaa 100644
--- a/ddl/ddl_api.go
+++ b/ddl/ddl_api.go
@@ -19,6 +19,7 @@ package ddl
 
 import (
 	"fmt"
+	"strconv"
 	"strings"
 	"time"
 
@@ -353,9 +354,15 @@ func getDefaultValue(ctx context.Context, c *ast.ColumnOption, tp byte, fsp int)
 	if err != nil {
 		return nil, errors.Trace(err)
 	}
+
 	if v.IsNull() {
 		return nil, nil
 	}
+
+	if v.Kind() == types.KindMysqlHex {
+		return strconv.FormatInt(v.GetMysqlHex().Value, 10), nil
+	}
+
 	return v.ToString()
 }
 
diff --git a/ddl/ddl_db_test.go b/ddl/ddl_db_test.go
index 4ff59884c0bd3..2d7c068e5cd65 100644
--- a/ddl/ddl_db_test.go
+++ b/ddl/ddl_db_test.go
@@ -1093,3 +1093,21 @@ out:
 	expected := fmt.Sprintf("%d %d", updateCnt, 3)
 	s.tk.MustQuery("select c2, c3 from tnn where c1 = 99").Check(testkit.Rows(expected))
 }
+
+func (s *testDBSuite) TestIssue2858And2717(c *C) {
+	defer testleak.AfterTest(c)()
+	s.tk = testkit.NewTestKit(c, s.store)
+	s.tk.MustExec("use " + s.schemaName)
+
+	s.tk.MustExec("create table t_issue_2858_bit (a bit(64) default b'0')")
+	s.tk.MustExec("insert into t_issue_2858_bit value ()")
+	s.tk.MustExec(`insert into t_issue_2858_bit values (100), ('10'), ('\0')`)
+	s.tk.MustQuery("select a+0 from t_issue_2858_bit").Check([][]interface{}{{0}, {100}, {0x3130}, {0}})
+	s.tk.MustExec(`alter table t_issue_2858_bit alter column a set default '\0'`)
+
+	s.tk.MustExec("create table t_issue_2858_hex (a int default 0x123)")
+	s.tk.MustExec("insert into t_issue_2858_hex value ()")
+	s.tk.MustExec("insert into t_issue_2858_hex values (123), (0x321)")
+	s.tk.MustQuery("select a from t_issue_2858_hex").Check([][]interface{}{{0x123}, {123}, {0x321}})
+	s.tk.MustExec(`alter table t_issue_2858_hex alter column a set default 0x321`)
+}
diff --git a/util/types/bit.go b/util/types/bit.go
index 8fbcd80e10b9f..9247c921c7ddd 100644
--- a/util/types/bit.go
+++ b/util/types/bit.go
@@ -19,6 +19,7 @@ import (
 	"strings"
 
 	"github.com/juju/errors"
+	"github.com/pingcap/tidb/util/hack"
 )
 
 // Bit is for mysql bit type.
@@ -104,3 +105,33 @@ func ParseBit(s string, width int) (Bit, error) {
 
 	return Bit{Value: n, Width: width}, nil
 }
+
+// ParseStringToBitValue parses the string for bit type into uint64.
+func ParseStringToBitValue(s string, width int) (uint64, error) {
+	if len(s) == 0 {
+		return 0, errors.Errorf("invalid empty string for parsing bit value")
+	}
+
+	b := hack.Slice(s)
+	if width == UnspecifiedBitWidth {
+		width = len(b) * 8
+	}
+	if width == 0 {
+		width = MinBitWidth
+	}
+	if width < MinBitWidth || width > MaxBitWidth {
+		return 0, errors.Errorf("invalid display width for bit type, must in [1, 64], but %d", width)
+	}
+
+	var n uint64
+	l := len(b)
+	for i := range b {
+		n += uint64(b[l-i-1]) << uint(i*8)
+	}
+
+	if n > (uint64(1)<<uint64(width))-1 {
+		return 0, errors.Errorf("bit %s is too long for width %d", s, width)
+	}
+
+	return n, nil
+}
diff --git a/util/types/bit_test.go b/util/types/bit_test.go
index af71ea9a211c8..e4e0b6aef18c0 100644
--- a/util/types/bit_test.go
+++ b/util/types/bit_test.go
@@ -43,6 +43,10 @@ func (s *testBitSuite) TestBit(c *C) {
 		c.Assert(b.ToNumber(), Equals, float64(t.Number))
 		c.Assert(b.String(), Equals, t.String)
 		c.Assert(b.ToString(), Equals, t.BitString)
+
+		n, err := ParseStringToBitValue(t.BitString, t.Width)
+		c.Assert(err, IsNil)
+		c.Assert(n, Equals, uint64(t.Number))
 	}
 
 	tblErr := []struct {
diff --git a/util/types/convert_test.go b/util/types/convert_test.go
index 10d2333e3d01f..0fd3616f730db 100644
--- a/util/types/convert_test.go
+++ b/util/types/convert_test.go
@@ -192,11 +192,12 @@ func (s *testTypeConvertSuite) TestConvertType(c *C) {
 
 	// For TypeBit
 	ft = NewFieldType(mysql.TypeBit)
-	ft.Flen = 8
+	ft.Flen = 24
 	v, err = Convert("100", ft)
 	c.Assert(err, IsNil)
-	c.Assert(v, Equals, Bit{Value: 100, Width: 8})
+	c.Assert(v, Equals, Bit{Value: 3223600, Width: 24})
 
+	ft.Flen = 8
 	v, err = Convert(Hex{Value: 100}, ft)
 	c.Assert(err, IsNil)
 	c.Assert(v, Equals, Bit{Value: 100, Width: 8})
diff --git a/util/types/datum.go b/util/types/datum.go
index 7a1b1cdd73321..540cd0d1ba8d6 100644
--- a/util/types/datum.go
+++ b/util/types/datum.go
@@ -1044,7 +1044,17 @@ func (d *Datum) convertToMysqlYear(sc *variable.StatementContext, target *FieldT
 }
 
 func (d *Datum) convertToMysqlBit(sc *variable.StatementContext, target *FieldType) (Datum, error) {
-	x, err := d.convertToUint(sc, target)
+	var (
+		x   Datum
+		err error
+	)
+	if d.Kind() == KindString {
+		var n uint64
+		n, err = ParseStringToBitValue(d.GetString(), target.Flen)
+		x = NewUintDatum(n)
+	} else {
+		x, err = d.convertToUint(sc, target)
+	}
 	if err != nil {
 		return x, errors.Trace(err)
 	}