Backport 7297: VStreamer Events: remove preceding zeroes from decimals in Row Events

go/mysql/binlog_event_rbr.go

@@ -22,6 +22,7 @@ import (
 	"fmt"
 	"math"
 	"strconv"
+	"strings"
 	"time"
 
 	"vitess.io/vitess/go/sqltypes"
@@ -764,8 +765,21 @@ func CellValue(data []byte, pos int, typ byte, metadata uint16, styp querypb.Typ
 			}
 		}
 
-		return sqltypes.MakeTrusted(querypb.Type_DECIMAL,
-			txt.Bytes()), l, nil
+		// remove preceding 0s from the integral part, otherwise we get "000000000001.23" instead of "1.23"
+		trimPrecedingZeroes := func(b []byte) []byte {
+			s := string(b)
+			isNegative := false
+			if s[0] == '-' {
+				isNegative = true
+				s = s[1:]
+			}
+			s = strings.TrimLeft(s, "0")
+			if isNegative {
+				s = fmt.Sprintf("-%s", s)
+			}
+			return []byte(s)
+		}
+		return sqltypes.MakeTrusted(querypb.Type_DECIMAL, trimPrecedingZeroes(txt.Bytes())), l, nil
 
 	case TypeEnum:
 		switch metadata & 0xff {

go/mysql/binlog_event_rbr_test.go

@@ -473,7 +473,7 @@ func TestCellLengthAndData(t *testing.T) {
 		metadata: 20<<8 | 2, // DECIMAL(20,2)
 		data:     []byte{0x80, 0x00, 0x00, 0x00, 0x00, 0x00, 0x0, 0x01, 0x0a},
 		out: sqltypes.MakeTrusted(querypb.Type_DECIMAL,
-			[]byte("000000000000000001.10")),
+			[]byte("1.10")),
 	}, {
 		typ:      TypeBlob,
 		metadata: 1,

go/vt/vttablet/tabletserver/vstreamer/vstreamer_test.go

@@ -1512,13 +1512,15 @@ func TestTypes(t *testing.T) {
 		"create table vitess_strings(vb varbinary(16), c char(16), vc varchar(16), b binary(4), tb tinyblob, bl blob, ttx tinytext, tx text, en enum('a','b'), s set('a','b'), primary key(vb))",
 		"create table vitess_misc(id int, b bit(8), d date, dt datetime, t time, g geometry, primary key(id))",
 		"create table vitess_null(id int, val varbinary(128), primary key(id))",
+		"create table vitess_decimal(id int, dec1 decimal(12,4), dec2 decimal(13,4), primary key(id))",
 	})
 	defer execStatements(t, []string{
 		"drop table vitess_ints",
 		"drop table vitess_fracts",
 		"drop table vitess_strings",
 		"drop table vitess_misc",
 		"drop table vitess_null",
+		"drop table vitess_decimal",
 	})
 	engine.se.Reload(context.Background())
 
@@ -1592,6 +1594,35 @@ func TestTypes(t *testing.T) {
 			`gtid`,
 			`commit`,
 		}},
+	}, {
+		input: []string{
+			"insert into vitess_decimal values(1, 1.23, 1.23)",
+			"insert into vitess_decimal values(2, -1.23, -1.23)",
+			"insert into vitess_decimal values(3, 0000000001.23, 0000000001.23)",
+			"insert into vitess_decimal values(4, -0000000001.23, -0000000001.23)",
+		},
+		output: [][]string{{
+			`begin`,
+			`type:FIELD field_event:<table_name:"vitess_decimal" fields:<name:"id" type:INT32 table:"vitess_decimal" org_table:"vitess_decimal" database:"vttest" org_name:"id" column_length:11 charset:63 > fields:<name:"dec1" type:DECIMAL table:"vitess_decimal" org_table:"vitess_decimal" database:"vttest" org_name:"dec1" column_length:14 charset:63 decimals:4 > fields:<name:"dec2" type:DECIMAL table:"vitess_decimal" org_table:"vitess_decimal" database:"vttest" org_name:"dec2" column_length:15 charset:63 decimals:4 > > `,
+			`type:ROW row_event:<table_name:"vitess_decimal" row_changes:<after:<lengths:1 lengths:6 lengths:6 values:"11.23001.2300" > > > `,
+			`gtid`,
+			`commit`,
+		}, {
+			`begin`,
+			`type:ROW row_event:<table_name:"vitess_decimal" row_changes:<after:<lengths:1 lengths:7 lengths:7 values:"2-1.2300-1.2300" > > > `,
+			`gtid`,
+			`commit`,
+		}, {
+			`begin`,
+			`type:ROW row_event:<table_name:"vitess_decimal" row_changes:<after:<lengths:1 lengths:6 lengths:6 values:"31.23001.2300" > > > `,
+			`gtid`,
+			`commit`,
+		}, {
+			`begin`,
+			`type:ROW row_event:<table_name:"vitess_decimal" row_changes:<after:<lengths:1 lengths:7 lengths:7 values:"4-1.2300-1.2300" > > > `,
+			`gtid`,
+			`commit`,
+		}},
 	}}
 	runCases(t, nil, testcases, "", nil)
 }