table/tables: fix panic (#1952)

fix panic

table/tables/index.go

@@ -278,8 +278,9 @@ func (c *index) Exist(rm kv.RetrieverMutator, indexedValues []types.Datum, h int
 func (c *index) FetchValues(r []types.Datum) ([]types.Datum, error) {
 	vals := make([]types.Datum, len(c.idxInfo.Columns))
 	for i, ic := range c.idxInfo.Columns {
-		if ic.Offset < 0 || ic.Offset > len(r) {
-			return nil, table.ErrIndexOutBound.Gen("Index column offset out of bound")
+		if ic.Offset < 0 || ic.Offset >= len(r) {
+			return nil, table.ErrIndexOutBound.Gen("Index column %s offset out of bound, offset: %d, row: %v",
+				ic.Name, ic.Offset, r)
 		}
 		vals[i] = r[ic.Offset]
 	}

table/tables/index_test.go

@@ -169,6 +169,9 @@ func (s *testIndexSuite) TestIndex(c *C) {
 
 	err = txn.Commit()
 	c.Assert(err, IsNil)
+
+	_, err = index.FetchValues(make([]types.Datum, 0))
+	c.Assert(err, NotNil)
 }
 
 func (s *testIndexSuite) TestCombineIndexSeek(c *C) {

table/tables/tables.go

@@ -418,7 +418,10 @@ func (t *Table) addIndices(ctx context.Context, recordID int64, r []types.Datum,
 			// if index is in delete only or delete reorganization state, we can't add it.
 			continue
 		}
-		colVals, _ := v.FetchValues(r)
+		colVals, err2 := v.FetchValues(r)
+		if err2 != nil {
+			return 0, errors.Trace(err2)
+		}
 		var dupKeyErr error
 		if v.Meta().Unique || v.Meta().Primary {
 			entryKey, err1 := t.genIndexKeyStr(colVals)