JPEG: Call Seek(0, 0) before opening image #2462 #2463

Found this here, although I'm really not sure how this should fix it:
- https://github.com/golang/go/issues/45902#issuecomment-1007953723

According to the tests I added, the error "unexpected EOF" remains!
At least this change shouldn't break anything either.... Help is more
than welcome if someone has more time to read through all the issue
comments.

internal/photoprism/mediafile.go

@@ -942,10 +942,19 @@ func (m *MediaFile) DecodeConfig() (_ *image.Config, err error) {
 
 	defer file.Close()
 
+	// Reset file offset.
+	// see https://github.com/golang/go/issues/45902#issuecomment-1007953723
+	_, err = file.Seek(0, 0)
+
+	if err != nil {
+		return nil, fmt.Errorf("%s on seek", err)
+	}
+
+	// Decode image config (dimensions).
 	cfg, _, err := image.DecodeConfig(file)
 
 	if err != nil {
-		return nil, err
+		return nil, fmt.Errorf("%s while decoding", err)
 	}
 
 	m.imageConfig = &cfg
@@ -1254,6 +1263,15 @@ func (m *MediaFile) ColorProfile() string {
 
 	defer fileReader.Close()
 
+	// Reset file offset.
+	// see https://github.com/golang/go/issues/45902#issuecomment-1007953723
+	_, err = fileReader.Seek(0, 0)
+
+	if err != nil {
+		log.Warnf("media: %s in %s on seek [%s]", err, logName, time.Since(start))
+		return ""
+	}
+
 	// Read color metadata.
 	md, _, err := autometa.Load(fileReader)
 

internal/thumb/open_jpeg.go

@@ -30,9 +30,18 @@ func OpenJpeg(fileName string, orientation int) (result image.Image, err error)
 
 	defer fileReader.Close()
 
+	// Reset file offset.
+	// see https://github.com/golang/go/issues/45902#issuecomment-1007953723
+	_, err = fileReader.Seek(0, 0)
+
+	if err != nil {
+		return result, fmt.Errorf("%s on seek", err)
+	}
+
 	// Read color metadata.
 	md, imgStream, err := autometa.Load(fileReader)
 
+	// Decode image.
 	var img image.Image
 
 	if err != nil {
@@ -43,7 +52,7 @@ func OpenJpeg(fileName string, orientation int) (result image.Image, err error)
 	}
 
 	if err != nil {
-		return result, err
+		return result, fmt.Errorf("%s while decoding", err)
 	}
 
 	// Read ICC profile and convert colors if possible.

internal/thumb/open_jpeg_test.go

@@ -0,0 +1,35 @@
+package thumb
+
+import (
+	"testing"
+)
+
+func TestOpenJpeg(t *testing.T) {
+	t.Run("testdata/example.jpg", func(t *testing.T) {
+		img, err := OpenJpeg("testdata/example.jpg", 0)
+
+		if err != nil {
+			t.Fatal(err)
+		}
+
+		if img == nil {
+			t.Error("img must not be nil")
+		}
+	})
+	t.Run("testdata/broken.jpg", func(t *testing.T) {
+		if _, err := OpenJpeg("testdata/broken.jpg", 0); err == nil {
+			t.Error("unexpected EOF while decoding error expected")
+		}
+	})
+	t.Run("testdata/fixed.jpg", func(t *testing.T) {
+		img, err := OpenJpeg("testdata/fixed.jpg", 0)
+
+		if err != nil {
+			t.Fatal(err)
+		}
+
+		if img == nil {
+			t.Error("img must not be nil")
+		}
+	})
+}