1 files changed, 51 insertions, 18 deletions

diff --git a/vendor/github.com/rwcarlsen/goexif/exif/exif.go b/vendor/github.com/rwcarlsen/goexif/exif/exif.go
index b420729da..87166ee4e 100644
--- a/vendor/github.com/rwcarlsen/goexif/exif/exif.go
+++ b/vendor/github.com/rwcarlsen/goexif/exif/exif.go
@@ -201,14 +201,16 @@ type Exif struct {
 	Raw  []byte
 }
 
-// Decode parses EXIF-encoded data from r and returns a queryable Exif
-// object. After the exif data section is called and the tiff structure
-// decoded, each registered parser is called (in order of registration). If
-// one parser returns an error, decoding terminates and the remaining
-// parsers are not called.
-// The error can be inspected with functions such as IsCriticalError to
-// determine whether the returned object might still be usable.
+// Decode parses EXIF data from r (a TIFF, JPEG, or raw EXIF block)
+// and returns a queryable Exif object. After the EXIF data section is
+// called and the TIFF structure is decoded, each registered parser is
+// called (in order of registration). If one parser returns an error,
+// decoding terminates and the remaining parsers are not called.
+//
+// The error can be inspected with functions such as IsCriticalError
+// to determine whether the returned object might still be usable.
 func Decode(r io.Reader) (*Exif, error) {
+
 	// EXIF data in JPEG is stored in the APP1 marker. EXIF data uses the TIFF
 	// format to store data.
 	// If we're parsing a TIFF image, we don't need to strip away any data.
@@ -216,15 +218,14 @@ func Decode(r io.Reader) (*Exif, error) {
 	// marker and also the EXIF header.
 
 	header := make([]byte, 4)
-	n, err := r.Read(header)
+	n, err := io.ReadFull(r, header)
 	if err != nil {
-		return nil, err
-	}
-	if n < len(header) {
-		return nil, errors.New("exif: short read on header")
+		return nil, fmt.Errorf("exif: error reading 4 byte header, got %d, %v", n, err)
 	}
 
 	var isTiff bool
+	var isRawExif bool
+	var assumeJPEG bool
 	switch string(header) {
 	case "II*\x00":
 		// TIFF - Little endian (Intel)
@@ -232,8 +233,11 @@ func Decode(r io.Reader) (*Exif, error) {
 	case "MM\x00*":
 		// TIFF - Big endian (Motorola)
 		isTiff = true
+	case "Exif":
+		isRawExif = true
 	default:
 		// Not TIFF, assume JPEG
+		assumeJPEG = true
 	}
 
 	// Put the header bytes back into the reader.
@@ -241,9 +245,20 @@ func Decode(r io.Reader) (*Exif, error) {
 	var (
 		er  *bytes.Reader
 		tif *tiff.Tiff
+		sec *appSec
 	)
 
-	if isTiff {
+	switch {
+	case isRawExif:
+		var header [6]byte
+		if _, err := io.ReadFull(r, header[:]); err != nil {
+			return nil, fmt.Errorf("exif: unexpected raw exif header read error")
+		}
+		if got, want := string(header[:]), "Exif\x00\x00"; got != want {
+			return nil, fmt.Errorf("exif: unexpected raw exif header; got %q, want %q", got, want)
+		}
+		fallthrough
+	case isTiff:
 		// Functions below need the IFDs from the TIFF data to be stored in a
 		// *bytes.Reader.  We use TeeReader to get a copy of the bytes as a
 		// side-effect of tiff.Decode() doing its work.
@@ -251,9 +266,8 @@ func Decode(r io.Reader) (*Exif, error) {
 		tr := io.TeeReader(r, b)
 		tif, err = tiff.Decode(tr)
 		er = bytes.NewReader(b.Bytes())
-	} else {
+	case assumeJPEG:
 		// Locate the JPEG APP1 header.
-		var sec *appSec
 		sec, err = newAppSec(jpeg_APP1, r)
 		if err != nil {
 			return nil, err
@@ -368,8 +382,27 @@ func (x *Exif) DateTime() (time.Time, error) {
 	exifTimeLayout := "2006:01:02 15:04:05"
 	dateStr := strings.TrimRight(string(tag.Val), "\x00")
 	// TODO(bradfitz,mpl): look for timezone offset, GPS time, etc.
-	// For now, just always return the time.Local timezone.
-	return time.ParseInLocation(exifTimeLayout, dateStr, time.Local)
+	timeZone := time.Local
+	if tz, _ := x.TimeZone(); tz != nil {
+		timeZone = tz
+	}
+	return time.ParseInLocation(exifTimeLayout, dateStr, timeZone)
+}
+
+func (x *Exif) TimeZone() (*time.Location, error) {
+	// TODO: parse more timezone fields (e.g. Nikon WorldTime).
+	timeInfo, err := x.Get("Canon.TimeInfo")
+	if err != nil {
+		return nil, err
+	}
+	if timeInfo.Count < 2 {
+		return nil, errors.New("Canon.TimeInfo does not contain timezone")
+	}
+	offsetMinutes, err := timeInfo.Int(1)
+	if err != nil {
+		return nil, err
+	}
+	return time.FixedZone("", offsetMinutes*60), nil
 }
 
 func ratFloat(num, dem int64) float64 {
@@ -574,7 +607,7 @@ func newAppSec(marker byte, r io.Reader) (*appSec, error) {
 		}
 
 		dataLenBytes := make([]byte, 2)
-		for k,_ := range dataLenBytes {
+		for k, _ := range dataLenBytes {
 			c, err := br.ReadByte()
 			if err != nil {
 				return nil, err