resources/image: Fix nilpointer for images with no Exif

E.g. PNG files.

Fixes #7688

4 files changed, 16 insertions, 11 deletions

diff --git a/resources/image.go b/resources/image.go
index d1d9f650d..e999c5d96 100644
--- a/resources/image.go
+++ b/resources/image.go
@@ -71,11 +71,11 @@ type imageMeta struct {
 	Exif *exif.Exif
 }
 
-func (i *imageResource) Exif() (*exif.Exif, error) {
+func (i *imageResource) Exif() *exif.Exif {
 	return i.root.getExif()
 }
 
-func (i *imageResource) getExif() (*exif.Exif, error) {
+func (i *imageResource) getExif() *exif.Exif {
 
 	i.metaInit.Do(func() {
 
@@ -131,10 +131,14 @@ func (i *imageResource) getExif() (*exif.Exif, error) {
 	})
 
 	if i.metaInitErr != nil {
-		return nil, i.metaInitErr
+		panic(fmt.Sprintf("metadata init failed: %s", i.metaInitErr))
 	}
 
-	return i.meta.Exif, nil
+	if i.meta == nil {
+		return nil
+	}
+
+	return i.meta.Exif
 }
 
 func (i *imageResource) Clone() resource.Resource {
diff --git a/resources/image_test.go b/resources/image_test.go
index f98d9f4bb..1be9a5f8d 100644
--- a/resources/image_test.go
+++ b/resources/image_test.go
@@ -321,6 +321,7 @@ func TestImageResize8BitPNG(t *testing.T) {
 	c.Assert(image.MediaType().Type(), qt.Equals, "image/png")
 	c.Assert(image.RelPermalink(), qt.Equals, "/a/gohugoio.png")
 	c.Assert(image.ResourceType(), qt.Equals, "image")
+	c.Assert(image.Exif(), qt.IsNil)
 
 	resized, err := image.Resize("800x")
 	c.Assert(err, qt.IsNil)
@@ -337,12 +338,14 @@ func TestImageResizeInSubPath(t *testing.T) {
 	c.Assert(image.MediaType(), eq, media.PNGType)
 	c.Assert(image.RelPermalink(), qt.Equals, "/a/sub/gohugoio2.png")
 	c.Assert(image.ResourceType(), qt.Equals, "image")
+	c.Assert(image.Exif(), qt.IsNil)
 
 	resized, err := image.Resize("101x101")
 	c.Assert(err, qt.IsNil)
 	c.Assert(resized.MediaType().Type(), qt.Equals, "image/png")
 	c.Assert(resized.RelPermalink(), qt.Equals, "/a/sub/gohugoio2_hu0e1b9e4a4be4d6f86c7b37b9ccce3fbc_73886_101x101_resize_linear_2.png")
 	c.Assert(resized.Width(), qt.Equals, 101)
+	c.Assert(resized.Exif(), qt.IsNil)
 
 	publishedImageFilename := filepath.Clean(resized.RelPermalink())
 
@@ -387,8 +390,7 @@ func TestImageExif(t *testing.T) {
 	image := fetchResourceForSpec(spec, c, "sunset.jpg").(resource.Image)
 
 	getAndCheckExif := func(c *qt.C, image resource.Image) {
-		x, err := image.Exif()
-		c.Assert(err, qt.IsNil)
+		x := image.Exif()
 		c.Assert(x, qt.Not(qt.IsNil))
 
 		c.Assert(x.Date.Format("2006-01-02"), qt.Equals, "2017-10-27")
@@ -403,7 +405,7 @@ func TestImageExif(t *testing.T) {
 		c.Assert(ok, qt.Equals, true)
 		c.Assert(lensModel, qt.Equals, "smc PENTAX-DA* 16-50mm F2.8 ED AL [IF] SDM")
 		resized, _ := image.Resize("300x200")
-		x2, _ := resized.Exif()
+		x2 := resized.Exif()
 		c.Assert(x2, eq, x)
 	}
 
@@ -426,8 +428,7 @@ func BenchmarkImageExif(b *testing.B) {
 	}
 
 	getAndCheckExif := func(c *qt.C, image resource.Image) {
-		x, err := image.Exif()
-		c.Assert(err, qt.IsNil)
+		x := image.Exif()
 		c.Assert(x, qt.Not(qt.IsNil))
 		c.Assert(x.Long, qt.Equals, float64(-4.50846))
 
diff --git a/resources/resource/resourcetypes.go b/resources/resource/resourcetypes.go
index 13ffc5ae3..f42372fa3 100644
--- a/resources/resource/resourcetypes.go
+++ b/resources/resource/resourcetypes.go
@@ -58,7 +58,7 @@ type ImageOps interface {
 	Fit(spec string) (Image, error)
 	Resize(spec string) (Image, error)
 	Filter(filters ...interface{}) (Image, error)
-	Exif() (*exif.Exif, error)
+	Exif() *exif.Exif
 }
 
 type ResourceTypeProvider interface {
diff --git a/resources/transform.go b/resources/transform.go
index 98aee3c2a..7793d3e0e 100644
--- a/resources/transform.go
+++ b/resources/transform.go
@@ -183,7 +183,7 @@ func (r *resourceAdapter) Height() int {
 	return r.getImageOps().Height()
 }
 
-func (r *resourceAdapter) Exif() (*exif.Exif, error) {
+func (r *resourceAdapter) Exif() *exif.Exif {
 	return r.getImageOps().Exif()
 }