Resolves #45 (#48)

Invalid EXIF support

Author: bigcat88

pillow_heif/misc.py

@@ -34,25 +34,28 @@ def set_orientation(info: dict, orientation: int = 1) -> Union[int, None]:
 
     original_orientation = None
     if info.get("exif", None):
-        tif_tag = info["exif"]
-        if tif_tag.startswith(b"Exif\x00\x00"):
-            tif_tag = tif_tag[6:]
-        endian_mark = "<" if tif_tag[0:2] == b"\x49\x49" else ">"
-        pointer = unpack(endian_mark + "L", tif_tag[4:8])[0]
-        tag_count = unpack(endian_mark + "H", tif_tag[pointer : pointer + 2])[0]
-        offset = pointer + 2
-        for tag_n in range(tag_count):
-            pointer = offset + 12 * tag_n
-            if unpack(endian_mark + "H", tif_tag[pointer : pointer + 2])[0] != 274:
-                continue
-            value = tif_tag[pointer + 8 : pointer + 12]
-            _original_orientation = unpack(endian_mark + "H", value[0:2])[0]
-            if _original_orientation != 1:
-                original_orientation = _original_orientation
-                p_value = 6 + pointer + 8
-                new_orientation = pack(endian_mark + "H", orientation)
-                info["exif"] = info["exif"][:p_value] + new_orientation + info["exif"][p_value + 2 :]
-                break
+        try:
+            tif_tag = info["exif"]
+            if tif_tag.startswith(b"Exif\x00\x00"):
+                tif_tag = tif_tag[6:]
+            endian_mark = "<" if tif_tag[0:2] == b"\x49\x49" else ">"
+            pointer = unpack(endian_mark + "L", tif_tag[4:8])[0]
+            tag_count = unpack(endian_mark + "H", tif_tag[pointer : pointer + 2])[0]
+            offset = pointer + 2
+            for tag_n in range(tag_count):
+                pointer = offset + 12 * tag_n
+                if unpack(endian_mark + "H", tif_tag[pointer : pointer + 2])[0] != 274:
+                    continue
+                value = tif_tag[pointer + 8 : pointer + 12]
+                _original_orientation = unpack(endian_mark + "H", value[0:2])[0]
+                if _original_orientation != 1:
+                    original_orientation = _original_orientation
+                    p_value = 6 + pointer + 8
+                    new_orientation = pack(endian_mark + "H", orientation)
+                    info["exif"] = info["exif"][:p_value] + new_orientation + info["exif"][p_value + 2 :]
+                    break
+        except Exception:  # noqa # pylint: disable=broad-except
+            pass
     if info.get("xmp", None):
         xmp_data = info["xmp"].decode("utf-8")
         match = re.search(r'tiff:Orientation(="|>)([0-9])', xmp_data)

tests/metadata_exif_test.py

@@ -40,12 +40,17 @@ def pil_image_with_exif():
     exif = im.getexif()  # noqa
     assert exif[0x010E] == exif_desc_value
     out_im_heif = BytesIO()
-    im.save(out_im_heif, format=save_format)
+    im.save(out_im_heif, format=save_format)  # saving to HEIF(AVIF)
     im_heif = Image.open(out_im_heif)
     assert im_heif.info["exif"]
     assert isinstance(im_heif.info["exif"], bytes)
     exif = im_heif.getexif()  # noqa
     assert exif[0x010E] == exif_desc_value
+    out_im = BytesIO()
+    im_heif.save(out_im, format=im_format, exif=im_heif.getexif())  # saving back to original format
+    im = Image.open(out_im)
+    exif = im.getexif()  # noqa
+    assert exif[0x010E] == exif_desc_value
 
 
 @pytest.mark.skipif(not helpers.hevc_enc(), reason="Requires HEIF encoder.")
@@ -159,3 +164,14 @@ def test_heif_multi_frame_exif_add_remove():
     im_heif_no_exif = pillow_heif.open_heif(out_heif_no_exif)
     assert "exif" not in im_heif_no_exif[0].info or im_heif_no_exif[0].info["exif"] is None
     assert "exif" not in im_heif_no_exif[1].info or im_heif_no_exif[1].info["exif"] is None
+
+
+@pytest.mark.skipif(not helpers.hevc_enc(), reason="Requires HEIF encoder.")
+def test_corrupted_exif():
+    exif_data = b"This_is_not_valid_EXIF_data"
+    out_im = BytesIO()
+    helpers.gradient_rgb().save(out_im, format="HEIF", exif=exif_data)
+    im = Image.open(out_im)
+    with pytest.raises(SyntaxError):
+        im.getexif()
+    assert im.info["exif"] == exif_data