lint - fix all errcheck

canal/canal.go

@@ -249,7 +249,7 @@ func (c *Canal) Close() {
 	c.conn = nil
 	c.connLock.Unlock()
 
-	c.eventHandler.OnPosSynced(c.master.Position(), c.master.GTIDSet(), true)
+	_ = c.eventHandler.OnPosSynced(c.master.Position(), c.master.GTIDSet(), true)
 }
 
 func (c *Canal) WaitDumpDone() <-chan struct{} {

client/resp.go

@@ -142,7 +142,7 @@ func (c *Conn) handleAuthResult() error {
 				}
 			}
 		} else {
-			errors.Errorf("invalid packet")
+			return errors.Errorf("invalid packet %x", data[0])
 		}
 	} else if c.authPluginName == AUTH_SHA256_PASSWORD {
 		if len(data) == 0 {

dump/dump.go

@@ -232,7 +232,10 @@ func (d *Dumper) Dump(w io.Writer) error {
 		// If we only dump some tables, the dump data will not have database name
 		// which makes us hard to parse, so here we add it manually.
 
-		w.Write([]byte(fmt.Sprintf("USE `%s`;\n", d.TableDB)))
+		_, err := w.Write([]byte(fmt.Sprintf("USE `%s`;\n", d.TableDB)))
+		if err != nil {
+			return fmt.Errorf(`could not write USE command: %w`, err)
+		}
 	}
 
 	log.Infof("exec mysqldump with %v", args)
@@ -251,12 +254,12 @@ func (d *Dumper) DumpAndParse(h ParseHandler) error {
 	done := make(chan error, 1)
 	go func() {
 		err := Parse(r, h, !d.masterDataSkipped)
-		r.CloseWithError(err)
+		_ = r.CloseWithError(err)
 		done <- err
 	}()
 
 	err := d.Dump(w)
-	w.CloseWithError(err)
+	_ = w.CloseWithError(err)
 
 	err = <-done
 

dump/dump_test.go

@@ -180,7 +180,8 @@ e7574090-b123-11e8-8bb4-005056a29643:1-12'
 		reader := strings.NewReader(tt.input)
 		var handler = new(testParseHandler)
 
-		Parse(reader, handler, true)
+		err := Parse(reader, handler, true)
+		c.Assert(err, IsNil)
 
 		if tt.expected == "" {
 			if handler.gset != nil {

mysql/mysql_gtid.go

@@ -232,14 +232,14 @@ func (s *UUIDSet) String() string {
 }
 
 func (s *UUIDSet) encode(w io.Writer) {
-	w.Write(s.SID.Bytes())
+	_, _ = w.Write(s.SID.Bytes())
 	n := int64(len(s.Intervals))
 
-	binary.Write(w, binary.LittleEndian, n)
+	_ = binary.Write(w, binary.LittleEndian, n)
 
 	for _, i := range s.Intervals {
-		binary.Write(w, binary.LittleEndian, i.Start)
-		binary.Write(w, binary.LittleEndian, i.Stop)
+		_ = binary.Write(w, binary.LittleEndian, i.Start)
+		_ = binary.Write(w, binary.LittleEndian, i.Stop)
 	}
 }
 
@@ -448,7 +448,7 @@ func (s *MysqlGTIDSet) String() string {
 func (s *MysqlGTIDSet) Encode() []byte {
 	var buf bytes.Buffer
 
-	binary.Write(&buf, binary.LittleEndian, uint64(len(s.Sets)))
+	_ = binary.Write(&buf, binary.LittleEndian, uint64(len(s.Sets)))
 
 	for i := range s.Sets {
 		s.Sets[i].encode(&buf)

mysql/mysql_test.go

@@ -102,7 +102,8 @@ func (t *mysqlTestSuite) TestMysqlUpdate(c *check.C) {
 	g1, err := ParseMysqlGTIDSet("3E11FA47-71CA-11E1-9E33-C80AA9429562:21-57")
 	c.Assert(err, check.IsNil)
 
-	g1.Update("3E11FA47-71CA-11E1-9E33-C80AA9429562:21-58")
+	err = g1.Update("3E11FA47-71CA-11E1-9E33-C80AA9429562:21-58")
+	c.Assert(err, check.IsNil)
 
 	c.Assert(strings.ToUpper(g1.String()), check.Equals, "3E11FA47-71CA-11E1-9E33-C80AA9429562:21-58")
 }

mysql/resultset_helper.go

@@ -146,15 +146,21 @@ func BuildSimpleTextResultset(names []string, values [][]interface{}) (*Resultse
 			}
 			if r.Fields[j] == nil {
 				r.Fields[j] = &Field{Name: hack.Slice(names[j]), Type: typ}
-				formatField(r.Fields[j], value)
+				err = formatField(r.Fields[j], value)
+				if err != nil {
+					return nil, errors.Trace(err)
+				}
 			} else if typ != r.Fields[j].Type {
 				// we got another type in the same column. in general, we treat it as an error, except
 				// the case, when old value was null, and the new one isn't null, so we can update
 				// type info for fields.
 				oldIsNull, newIsNull := r.Fields[j].Type == MYSQL_TYPE_NULL, typ == MYSQL_TYPE_NULL
 				if oldIsNull && !newIsNull { // old is null, new isn't, update type info.
 					r.Fields[j].Type = typ
-					formatField(r.Fields[j], value)
+					err = formatField(r.Fields[j], value)
+					if err != nil {
+						return nil, errors.Trace(err)
+					}
 				} else if !oldIsNull && !newIsNull { // different non-null types, that's an error.
 					return nil, errors.Errorf("row types aren't consistent")
 				}

replication/backup.go

@@ -22,7 +22,9 @@ func (b *BinlogSyncer) StartBackup(backupDir string, p Position, timeout time.Du
 	// Force use raw mode
 	b.parser.SetRawMode(true)
 
-	os.MkdirAll(backupDir, 0755)
+	if err := os.MkdirAll(backupDir, 0755); err != nil {
+		return errors.Trace(err)
+	}
 
 	s, err := b.StartSync(p)
 	if err != nil {

replication/binlogsyncer.go

@@ -183,7 +183,10 @@ func (b *BinlogSyncer) close() {
 	b.cancel()
 
 	if b.c != nil {
-		b.c.SetReadDeadline(time.Now().Add(100 * time.Millisecond))
+		err := b.c.SetReadDeadline(time.Now().Add(100 * time.Millisecond))
+		if err != nil {
+			log.Warnf(`could not set read deadline: %s`, err)
+		}
 	}
 
 	// kill last connection id
@@ -234,17 +237,19 @@ func (b *BinlogSyncer) registerSlave() error {
 	}
 
 	if len(b.cfg.Charset) != 0 {
-		b.c.SetCharset(b.cfg.Charset)
+		if err = b.c.SetCharset(b.cfg.Charset); err != nil {
+			return errors.Trace(err)
+		}
 	}
 
 	//set read timeout
 	if b.cfg.ReadTimeout > 0 {
-		b.c.SetReadDeadline(time.Now().Add(b.cfg.ReadTimeout))
+		_ = b.c.SetReadDeadline(time.Now().Add(b.cfg.ReadTimeout))
 	}
 
 	if b.cfg.RecvBufferSize > 0 {
 		if tcp, ok := b.c.Conn.Conn.(*net.TCPConn); ok {
-			tcp.SetReadBuffer(b.cfg.RecvBufferSize)
+			_ = tcp.SetReadBuffer(b.cfg.RecvBufferSize)
 		}
 	}
 
@@ -707,7 +712,7 @@ func (b *BinlogSyncer) onStream(s *BinlogStreamer) {
 
 		//set read timeout
 		if b.cfg.ReadTimeout > 0 {
-			b.c.SetReadDeadline(time.Now().Add(b.cfg.ReadTimeout))
+			_ = b.c.SetReadDeadline(time.Now().Add(b.cfg.ReadTimeout))
 		}
 
 		// Reset retry count on successful packet receieve

replication/replication_test.go

@@ -309,7 +309,7 @@ func (t *testSyncerSuite) testPositionSync(c *C) {
 
 	// Test re-sync.
 	time.Sleep(100 * time.Millisecond)
-	t.b.c.SetReadDeadline(time.Now().Add(time.Millisecond))
+	_ = t.b.c.SetReadDeadline(time.Now().Add(time.Millisecond))
 	time.Sleep(100 * time.Millisecond)
 
 	t.testSync(c, s)

server/command.go

@@ -110,10 +110,14 @@ func (c *Conn) dispatch(data []byte) interface{} {
 			return r
 		}
 	case COM_STMT_CLOSE:
-		c.handleStmtClose(data)
+		if err := c.handleStmtClose(data); err != nil {
+			return err
+		}
 		return noResponse{}
 	case COM_STMT_SEND_LONG_DATA:
-		c.handleStmtSendLongData(data)
+		if err := c.handleStmtSendLongData(data); err != nil {
+			return err
+		}
 		return noResponse{}
 	case COM_STMT_RESET:
 		if r, err := c.handleStmtReset(data); err != nil {

server/conn.go

@@ -107,7 +107,7 @@ func (c *Conn) handshake() error {
 		if err == ErrAccessDenied {
 			err = NewDefaultError(ER_ACCESS_DENIED_ERROR, c.user, c.LocalAddr().String(), "Yes")
 		}
-		c.writeError(err)
+		_ = c.writeError(err)
 		return err
 	}
 

server/example/server_example.go

@@ -44,7 +44,11 @@ func main() {
 			}
 
 			for {
-				conn.HandleCommand()
+				err = conn.HandleCommand()
+				if err != nil {
+					log.Errorf(`Could not handle command: %v`, err)
+					return
+				}
 			}
 		}()
 	}