Merged in mjpeg-extract-error (pull request #327)

Fixed mjpeg extract.go returning errors when it should not.

Approved-by: Saxon Milton <saxon.milton@gmail.com>

codec/mjpeg/extract.go

@@ -74,6 +74,7 @@ func (e *Extractor) Extract(dst io.Writer, src io.Reader, delay time.Duration) e
 
 		err = ctx.ParsePayload(p, m)
 		switch err {
+		case nil: // Do nothing.
 		case ErrNoFrameStart: // If no frame start then we continue until we get one.
 		default:
 			return fmt.Errorf("could not parse JPEG scan: %w", err)

codec/mjpeg/extract_test.go

@@ -0,0 +1,62 @@
+/*
+DESCRIPTION
+  extract_test.go provides testing for extract.go.
+
+AUTHOR
+  Scott Barnard <scott@ausocean.org>
+
+LICENSE
+  Copyright (C) 2020 the Australian Ocean Lab (AusOcean)
+
+  It is free software: you can redistribute it and/or modify them
+  under the terms of the GNU General Public License as published by the
+  Free Software Foundation, either version 3 of the License, or (at your
+  option) any later version.
+
+  It is distributed in the hope that it will be useful, but WITHOUT
+  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+  FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+  for more details.
+
+  You should have received a copy of the GNU General Public License
+  along with revid in gpl.txt. If not, see http://www.gnu.org/licenses.
+*/
+
+package mjpeg
+
+import (
+	"bytes"
+	"io"
+	"io/ioutil"
+	"testing"
+)
+
+type testReader struct {
+	i int
+}
+
+func (r *testReader) Read(b []byte) (int, error) {
+	if r.i >= len(testPackets) {
+		return 0, io.EOF
+	}
+	copy(b, testPackets[r.i])
+	r.i++
+	return len(testPackets[r.i-1]), nil
+}
+
+func TestExtract(t *testing.T) {
+	got := &bytes.Buffer{}
+	err := NewExtractor().Extract(got, &testReader{}, 0)
+	if err != nil {
+		t.Fatalf("could not extract: %v", err)
+	}
+
+	want, err := ioutil.ReadFile("testdata/expect.mjpeg")
+	if err != nil {
+		t.Fatalf("could not read file for wanted MJPEG data: %v", err)
+	}
+
+	if !bytes.Equal(got.Bytes(), want) {
+		t.Error("did not get expected result")
+	}
+}