Seek past the data when skipping a PSD layer

Tests/test_file_psd.py

@@ -111,6 +111,11 @@ def test_rgba():
         assert_image_equal_tofile(im, "Tests/images/imagedraw_square.png")
 
 
+def test_layer_skip():
+    with Image.open("Tests/images/five_channels.psd") as im:
+        assert im.n_frames == 1
+
+
 def test_icc_profile():
     with Image.open(test_file) as im:
         assert "icc_profile" in im.info

src/PIL/PsdImagePlugin.py

@@ -186,6 +186,9 @@ def read(size):
         ct_types = i16(read(2))
         types = list(range(ct_types))
         if len(types) > 4:
+            fp.seek(len(types) * 6 + 12, io.SEEK_CUR)
+            size = i32(read(4))
+            fp.seek(size, io.SEEK_CUR)
             continue
 
         for _ in types: