refactoring (*textRows).readRow in a more clear way

Fix error returns use utf8mb4 instead of utf8 in TestCharset (#1228) From MySQL 8.0.24, `SELECT @@character_set_connection` reports utf8mb3 or utf8mb4 instead of utf8. Because utf8 is currently an alias for utf8mb3, however at some point utf8 is expected to become a reference to utf8mb4. > ref. https://dev.mysql.com/doc/relnotes/mysql/8.0/en/news-8-0-24.html#mysqld-8-0-24-bug > Important Note: When a utf8mb3 collation was specified in a CREATE TABLE statement, SHOW CREATE TABLE, DEFAULT CHARSET, > the values of system variables containing character set names, > and the binary log all subsequently displayed the character set as utf8 which is becoming a synonym for utf8mb4. > Now in such cases, utf8mb3 is shown instead, and CREATE TABLE raises the warning 'collation_name' is a collation of the deprecated character set UTF8MB3. > Please consider using UTF8MB4 with an appropriate collation instead. (Bug #27225287, Bug #32085357, Bug #32122844) > > References: See also: Bug #30624990. The document says that we should use utf8mb4 instead of utf8, so we should follow it.

driver_test.go

@@ -1450,11 +1450,11 @@ func TestCharset(t *testing.T){
  mustSetCharset("charset=ascii", "ascii")
 
  // when the first charset is invalid, use the second
- mustSetCharset("charset=none,utf8", "utf8")
+ mustSetCharset("charset=none,utf8mb4", "utf8mb4")
 
  // when the first charset is valid, use it
- mustSetCharset("charset=ascii,utf8", "ascii")
- mustSetCharset("charset=utf8,ascii", "utf8")
+ mustSetCharset("charset=ascii,utf8mb4", "ascii")
+ mustSetCharset("charset=utf8mb4,ascii", "utf8mb4")
 }
 
 func TestFailingCharset(t *testing.T){

packets.go

@@ -761,40 +761,40 @@ func (rows *textRows) readRow(dest []driver.Value) error{
  }
 
  // RowSet Packet
- var n int
- var isNull bool
- pos := 0
+ var (
+ n int
+ isNull bool
+ pos int = 0
+ )
 
  for i := range dest{
  // Read bytes and convert to string
  dest[i], isNull, n, err = readLengthEncodedString(data[pos:])
  pos += n
- if err == nil{
- if !isNull{
- if !mc.parseTime{
- continue
- } else{
- switch rows.rs.columns[i].fieldType{
- case fieldTypeTimestamp, fieldTypeDateTime,
- fieldTypeDate, fieldTypeNewDate:
- dest[i], err = parseDateTime(
- dest[i].([]byte),
- mc.cfg.Loc,
- )
- if err == nil{
- continue
- }
- default:
- continue
- }
- }
 
- } else{
- dest[i] = nil
- continue
+ if err != nil{
+ return err
+ }
+
+ if isNull{
+ dest[i] = nil
+ continue
+ }
+
+ if !mc.parseTime{
+ continue
+ }
+
+ // Parse time field
+ switch rows.rs.columns[i].fieldType{
+ case fieldTypeTimestamp,
+ fieldTypeDateTime,
+ fieldTypeDate,
+ fieldTypeNewDate:
+ if dest[i], err = parseDateTime(dest[i].([]byte), mc.cfg.Loc); err != nil{
+ return err
  }
  }
- return err // err != nil
  }
 
  return nil