*: revert #10124 and remove sql mode PadCharToFullLength (#14007)

executor/distsql.go

@@ -154,9 +154,6 @@ func statementContextToFlags(sc *stmtctx.StatementContext) uint64 {
 	if sc.DividedByZeroAsWarning {
 		flags |= model.FlagDividedByZeroAsWarning
 	}
-	if sc.PadCharToFullLength {
-		flags |= model.FlagPadCharToFullLength
-	}
 	return flags
 }
 

executor/executor.go

@@ -1499,7 +1499,6 @@ func ResetContextOfStmt(ctx sessionctx.Context, s ast.StmtNode) (err error) {
 			sc.Priority = opts.Priority
 			sc.NotFillCache = !opts.SQLCache
 		}
-		sc.PadCharToFullLength = ctx.GetSessionVars().SQLMode.HasPadCharToFullLengthMode()
 		sc.CastStrToIntStrict = true
 	case *ast.ShowStmt:
 		sc.IgnoreTruncate = true

executor/point_get.go

@@ -27,7 +27,6 @@ import (
 	"github.com/pingcap/tidb/types"
 	"github.com/pingcap/tidb/util/chunk"
 	"github.com/pingcap/tidb/util/codec"
-	"github.com/pingcap/tidb/util/ranger"
 )
 
 func (b *executorBuilder) buildPointGet(p *plannercore.PointGetPlan) Executor {
@@ -157,7 +156,9 @@ func (e *PointGetExecutor) encodeIndexKey() (_ []byte, err error) {
 	for i := range e.idxVals {
 		colInfo := e.tblInfo.Columns[e.idxInfo.Columns[i].Offset]
 		if colInfo.Tp == mysql.TypeString || colInfo.Tp == mysql.TypeVarString || colInfo.Tp == mysql.TypeVarchar {
-			e.idxVals[i], err = ranger.HandlePadCharToFullLength(sc, &colInfo.FieldType, e.idxVals[i])
+			var str string
+			str, err = e.idxVals[i].ToString()
+			e.idxVals[i].SetString(str)
 		} else {
 			e.idxVals[i], err = table.CastValue(e.ctx, e.idxVals[i], colInfo)
 		}

expression/column.go

@@ -15,7 +15,6 @@ package expression
 
 import (
 	"fmt"
-	"strings"
 
 	"github.com/pingcap/errors"
 	"github.com/pingcap/parser/model"
@@ -71,10 +70,6 @@ func (col *CorrelatedColumn) EvalString(ctx sessionctx.Context, row chunk.Row) (
 		return "", true, nil
 	}
 	res, err := col.Data.ToString()
-	resLen := len([]rune(res))
-	if resLen < col.RetType.Flen && ctx.GetSessionVars().StmtCtx.PadCharToFullLength {
-		res = res + strings.Repeat(" ", col.RetType.Flen-resLen)
-	}
 	return res, err != nil, err
 }
 
@@ -249,12 +244,6 @@ func (col *Column) EvalString(ctx sessionctx.Context, row chunk.Row) (string, bo
 	}
 
 	val := row.GetString(col.Index)
-	if ctx.GetSessionVars().StmtCtx.PadCharToFullLength && col.GetType().Tp == mysql.TypeString {
-		valLen := len([]rune(val))
-		if valLen < col.RetType.Flen {
-			val = val + strings.Repeat(" ", col.RetType.Flen-valLen)
-		}
-	}
 	return val, false, nil
 }
 

go.sum

@@ -181,6 +181,7 @@ github.com/prometheus/procfs v0.0.0-20181005140218-185b4288413d h1:GoAlyOgbOEIFd
 github.com/prometheus/procfs v0.0.0-20181005140218-185b4288413d/go.mod h1:c3At6R/oaqEKCNdg8wHV1ftS6bRYblBhIjjI8uT2IGk=
 github.com/remyoudompheng/bigfft v0.0.0-20190512091148-babf20351dd7 h1:FUL3b97ZY2EPqg2NbXKuMHs5pXJB9hjj1fDHnF2vl28=
 github.com/remyoudompheng/bigfft v0.0.0-20190512091148-babf20351dd7/go.mod h1:qqbHyh8v60DhA7CoWK5oRCqLrMHRGoxYCSS9EjAz6Eo=
+github.com/sergi/go-diff v1.0.1-0.20180205163309-da645544ed44 h1:tB9NOR21++IjLyVx3/PCPhWMwqGNCMQEH96A6dMZ/gc=
 github.com/sergi/go-diff v1.0.1-0.20180205163309-da645544ed44/go.mod h1:0CfEIISq7TuYL3j771MWULgwwjU+GofnZX9QAmXWZgo=
 github.com/shirou/gopsutil v2.18.10+incompatible h1:cy84jW6EVRPa5g9HAHrlbxMSIjBhDSX0OFYyMYminYs=
 github.com/shirou/gopsutil v2.18.10+incompatible/go.mod h1:5b4v6he4MtMOwMlS0TUMTu2PcXUg8+E1lC7eC3UO/RA=

sessionctx/stmtctx/stmtctx.go

@@ -65,7 +65,6 @@ type StatementContext struct {
 	OverflowAsWarning      bool
 	InShowWarning          bool
 	UseCache               bool
-	PadCharToFullLength    bool
 	BatchCheck             bool
 	InNullRejectCheck      bool
 	AllowInvalidDate       bool

store/mockstore/mocktikv/cop_handler_dag.go

@@ -417,7 +417,6 @@ func flagsToStatementContext(flags uint64) *stmtctx.StatementContext {
 	sc := new(stmtctx.StatementContext)
 	sc.IgnoreTruncate = (flags & model.FlagIgnoreTruncate) > 0
 	sc.TruncateAsWarning = (flags & model.FlagTruncateAsWarning) > 0
-	sc.PadCharToFullLength = (flags & model.FlagPadCharToFullLength) > 0
 	return sc
 }
 

types/const_test.go

@@ -255,38 +255,6 @@ func (s *testMySQLConstSuite) TestIgnoreSpaceMode(c *C) {
 
 }
 
-func (s *testMySQLConstSuite) TestPadCharToFullLengthMode(c *C) {
-	tk := testkit.NewTestKit(c, s.store)
-	tk.MustExec("use test")
-	// test type `CHAR(n)`
-	tk.MustExec("drop table if exists t1")
-	tk.MustExec("create table t1 (a char(10));")
-	tk.MustExec("insert into t1 values ('xy');")
-	tk.MustExec("set sql_mode='';")
-	r := tk.MustQuery(`SELECT a='xy        ', char_length(a) FROM t1;`)
-	r.Check(testkit.Rows("0 2"))
-	r = tk.MustQuery(`SELECT count(*) FROM t1 WHERE a='xy        ';`)
-	r.Check(testkit.Rows("0"))
-	tk.MustExec("set sql_mode='PAD_CHAR_TO_FULL_LENGTH';")
-	r = tk.MustQuery(`SELECT a='xy        ', char_length(a) FROM t1;`)
-	r.Check(testkit.Rows("1 10"))
-	r = tk.MustQuery(`SELECT count(*) FROM t1 WHERE a='xy        ';`)
-	r.Check(testkit.Rows("1"))
-
-	// test type `VARCHAR(n)`
-	tk.MustExec("drop table if exists t1")
-	tk.MustExec("create table t1 (a varchar(10));")
-	tk.MustExec("insert into t1 values ('xy');")
-	tk.MustExec("set sql_mode='';")
-	r = tk.MustQuery(`SELECT a='xy        ', char_length(a) FROM t1;`)
-	r.Check(testkit.Rows("0 2"))
-	r = tk.MustQuery(`SELECT count(*) FROM t1 WHERE a='xy        ';`)
-	r.Check(testkit.Rows("0"))
-	tk.MustExec("set sql_mode='PAD_CHAR_TO_FULL_LENGTH';")
-	r = tk.MustQuery(`SELECT a='xy        ', char_length(a) FROM t1;`)
-	r.Check(testkit.Rows("0 2"))
-}
-
 func (s *testMySQLConstSuite) TestNoBackslashEscapesMode(c *C) {
 	tk := testkit.NewTestKit(c, s.store)
 	tk.MustExec("set sql_mode=''")

util/ranger/points.go

@@ -17,15 +17,12 @@ import (
 	"fmt"
 	"math"
 	"sort"
-	"strings"
 
 	"github.com/pingcap/errors"
 	"github.com/pingcap/parser/ast"
-	"github.com/pingcap/parser/charset"
 	"github.com/pingcap/parser/mysql"
 	"github.com/pingcap/parser/terror"
 	"github.com/pingcap/tidb/expression"
-	"github.com/pingcap/tidb/kv"
 	"github.com/pingcap/tidb/sessionctx/stmtctx"
 	"github.com/pingcap/tidb/types"
 	"github.com/pingcap/tidb/util/chunk"
@@ -245,11 +242,6 @@ func (r *builder) buildFormBinOp(expr *expression.ScalarFunction) []point {
 		return nil
 	}
 
-	value, err = HandlePadCharToFullLength(r.sc, ft, value)
-	if err != nil {
-		return nil
-	}
-
 	value, op, isValidRange := handleUnsignedIntCol(ft, value, op)
 	if !isValidRange {
 		return nil
@@ -286,64 +278,6 @@ func (r *builder) buildFormBinOp(expr *expression.ScalarFunction) []point {
 	return nil
 }
 
-// HandlePadCharToFullLength handles the "PAD_CHAR_TO_FULL_LENGTH" sql mode for
-// CHAR[N] index columns.
-// NOTE: kv.ErrNotExist is returned to indicate that this value can not match
-//		 any (key, value) pair in tikv storage. This error should be handled by
-//		 the caller.
-func HandlePadCharToFullLength(sc *stmtctx.StatementContext, ft *types.FieldType, val types.Datum) (types.Datum, error) {
-	isChar := (ft.Tp == mysql.TypeString)
-	isBinary := (isChar && ft.Collate == charset.CollationBin)
-	isVarchar := (ft.Tp == mysql.TypeVarString || ft.Tp == mysql.TypeVarchar)
-	isVarBinary := (isVarchar && ft.Collate == charset.CollationBin)
-
-	if !isChar && !isVarchar && !isBinary && !isVarBinary {
-		return val, nil
-	}
-
-	hasBinaryFlag := mysql.HasBinaryFlag(ft.Flag)
-	targetStr, err := val.ToString()
-	if err != nil {
-		return val, err
-	}
-
-	switch {
-	case isBinary || isVarBinary:
-		val.SetString(targetStr)
-		return val, nil
-	case isVarchar && hasBinaryFlag:
-		noTrailingSpace := strings.TrimRight(targetStr, " ")
-		if numSpacesToFill := ft.Flen - len(noTrailingSpace); numSpacesToFill > 0 {
-			noTrailingSpace += strings.Repeat(" ", numSpacesToFill)
-		}
-		val.SetString(noTrailingSpace)
-		return val, nil
-	case isVarchar && !hasBinaryFlag:
-		val.SetString(targetStr)
-		return val, nil
-	case isChar && hasBinaryFlag:
-		noTrailingSpace := strings.TrimRight(targetStr, " ")
-		val.SetString(noTrailingSpace)
-		return val, nil
-	case isChar && !hasBinaryFlag && !sc.PadCharToFullLength:
-		val.SetString(targetStr)
-		return val, nil
-	case isChar && !hasBinaryFlag && sc.PadCharToFullLength:
-		if len(targetStr) != ft.Flen {
-			// return kv.ErrNotExist to indicate that this value can not match any
-			// (key, value) pair in tikv storage.
-			return val, kv.ErrNotExist
-		}
-		// Trailing spaces of data typed "CHAR[N]" is trimed in the storage, we
-		// need to trim these trailing spaces as well.
-		noTrailingSpace := strings.TrimRight(targetStr, " ")
-		val.SetString(noTrailingSpace)
-		return val, nil
-	default:
-		return val, nil
-	}
-}
-
 // handleUnsignedIntCol handles the case when unsigned column meets negative integer value.
 // The three returned values are: fixed constant value, fixed operator, and a boolean
 // which indicates whether the range is valid or not.