1 files changed, 42 insertions, 15 deletions
diff --git a/libgo/go/image/png/reader_test.go b/libgo/go/image/png/reader_test.go
index fefceee3a5d..8314a833877 100644
--- a/libgo/go/image/png/reader_test.go
+++ b/libgo/go/image/png/reader_test.go
@@ -13,23 +13,23 @@ import (
 	"testing"
 )
 
-// The go PNG library currently supports only a subset of the full PNG specification.
-// In particular, bit depths other than 8 or 16 are not supported, nor are grayscale-
-// alpha images.
 var filenames = []string{
-	//"basn0g01",	// bit depth is not 8 or 16
-	//"basn0g02",	// bit depth is not 8 or 16
-	//"basn0g04",	// bit depth is not 8 or 16
+	"basn0g01",
+	"basn0g01-30",
+	"basn0g02",
+	"basn0g02-29",
+	"basn0g04",
+	"basn0g04-31",
 	"basn0g08",
 	"basn0g16",
 	"basn2c08",
 	"basn2c16",
-	//"basn3p01",	// bit depth is not 8 or 16
-	//"basn3p02",	// bit depth is not 8 or 16
-	//"basn3p04",	// bit depth is not 8 or 16
+	"basn3p01",
+	"basn3p02",
+	"basn3p04",
 	"basn3p08",
-	//"basn4a08",	// grayscale-alpha color model
-	//"basn4a16",	// grayscale-alpha color model
+	"basn4a08",
+	"basn4a16",
 	"basn6a08",
 	"basn6a16",
 }
@@ -58,7 +58,16 @@ func sng(w io.WriteCloser, filename string, png image.Image) {
 	cpm, _ := cm.(image.PalettedColorModel)
 	var paletted *image.Paletted
 	if cpm != nil {
-		bitdepth = 8
+		switch {
+		case len(cpm) <= 2:
+			bitdepth = 1
+		case len(cpm) <= 4:
+			bitdepth = 2
+		case len(cpm) <= 16:
+			bitdepth = 4
+		default:
+			bitdepth = 8
+		}
 		paletted = png.(*image.Paletted)
 	}
 
@@ -131,8 +140,15 @@ func sng(w io.WriteCloser, filename string, png image.Image) {
 				fmt.Fprintf(w, "%04x%04x%04x%04x ", nrgba64.R, nrgba64.G, nrgba64.B, nrgba64.A)
 			}
 		case cpm != nil:
+			var b, c int
 			for x := bounds.Min.X; x < bounds.Max.X; x++ {
-				fmt.Fprintf(w, "%02x", paletted.ColorIndexAt(x, y))
+				b = b<<uint(bitdepth) | int(paletted.ColorIndexAt(x, y))
+				c++
+				if c == 8/bitdepth {
+					fmt.Fprintf(w, "%02x", b)
+					b = 0
+					c = 0
+				}
 			}
 		}
 		io.WriteString(w, "\n")
@@ -143,14 +159,25 @@ func sng(w io.WriteCloser, filename string, png image.Image) {
 func TestReader(t *testing.T) {
 	for _, fn := range filenames {
 		// Read the .png file.
-		image, err := readPng("testdata/pngsuite/" + fn + ".png")
+		img, err := readPng("testdata/pngsuite/" + fn + ".png")
 		if err != nil {
 			t.Error(fn, err)
 			continue
 		}
+
+		if fn == "basn4a16" {
+			// basn4a16.sng is gray + alpha but sng() will produce true color + alpha
+			// so we just check a single random pixel.
+			c := img.At(2, 1).(image.NRGBA64Color)
+			if c.R != 0x11a7 || c.G != 0x11a7 || c.B != 0x11a7 || c.A != 0x1085 {
+				t.Error(fn, fmt.Errorf("wrong pixel value at (2, 1): %x", c))
+			}
+			continue
+		}
+
 		piper, pipew := io.Pipe()
 		pb := bufio.NewReader(piper)
-		go sng(pipew, fn, image)
+		go sng(pipew, fn, img)
 		defer piper.Close()
 
 		// Read the .sng file.