Merge pull request #31 from jaddison/exif-fixes

Explicit error handling fixes

.travis.yml

@@ -9,10 +9,10 @@ python:
  - 3.3
  - 3.4
  - 3.5
- - 3.6-dev
+ - 3.6
 
 install:
- - pip install pillow==2.9.0
+ - pip install pillow==4.0.0
  - pip install coveralls
 
 script:

doc/appendices.rst

@@ -82,3 +82,21 @@ On GoogleAppEngine, it can't save files on disk. Therefore files must be handled
 
     # transplant
     piexif.transplant(jpg_data1, jpg_data2, output)
+
+Invalid EXIF Thumbnails
+-----------------------
+
+EXIF data will sometimes be either corrupted or written by non-compliant software. When this happens, it's possible
+that the thumbnail stored in EXIF cannot be found when attempting to dump the EXIF dictionary.
+
+A good solution would be to remove the thumbnail from the EXIF dictionary and then re-attempt the dump:
+
+::
+
+    try:
+        exif_bytes = piexif.dump(exif_dict)
+    except InvalidImageDataError:
+        del exif_dict["1st"]
+        del exif_dict["thumbnail"]
+        exif_bytes = piexif.dump(exif_dict)
+

doc/changes.rst

@@ -1,6 +1,14 @@
 Changelog
 =========
 
+1.0.12
+------
+
+- Added explicit InvalidImageDataError exception to aid users. Related to https://github.com/hMatoba/Piexif/issues/30.
+- Fixed minor issue with tests.
+- Removed minor amounts of unused logic.
+- Updated .travis.yml for Python and Pillow versions.
+
 1.0.11
 ------
 

piexif/__init__.py

@@ -4,6 +4,7 @@
 from ._transplant import transplant
 from ._insert import insert
 from ._exif import *
+from ._exeptions import *
 
 
-VERSION = '1.0.11'
+VERSION = '1.0.12'

piexif/_common.py

@@ -1,11 +1,13 @@
 import struct
 
+from ._exeptions import InvalidImageDataError
+
 
 def split_into_segments(data):
     """Slices JPEG meta data into a list from JPEG binary data.
     """
     if data[0:2] != b"\xff\xd8":
-        raise ValueError("Given data isn't JPEG.")
+        raise InvalidImageDataError("Given data isn't JPEG.")
 
     head = 2
     segments = [b"\xff\xd8"]
@@ -21,7 +23,7 @@ def split_into_segments(data):
             head = endPoint
 
         if (head >= len(data)):
-            raise ValueError("Wrong JPEG data.")
+            raise InvalidImageDataError("Wrong JPEG data.")
     return segments
 
 def read_exif_from_file(filename):
@@ -31,10 +33,9 @@ def read_exif_from_file(filename):
     data = f.read(6)
 
     if data[0:2] != b"\xff\xd8":
-        raise ValueError("Given data isn't JPEG.")
+        raise InvalidImageDataError("Given data isn't JPEG.")
 
     head = data[2:6]
-    head_pos = 2
     HEAD_LENGTH = 4
     exif = None
     while 1:

piexif/_exeptions.py

@@ -0,0 +1,2 @@
+class InvalidImageDataError(ValueError):
+    pass

piexif/_insert.py

@@ -2,6 +2,7 @@
 import struct
 
 from ._common import *
+from ._exeptions import InvalidImageDataError
 
 
 def insert(exif, image, new_file=None):
@@ -24,10 +25,9 @@ def insert(exif, image, new_file=None):
         with open(image, 'rb') as f:
             image_data = f.read()
         if image_data[0:2] != b"\xff\xd8":
-            raise ValueError
+            raise InvalidImageDataError
         output_file = True
     segments = split_into_segments(image_data)
-    image_exif = get_exif_seg(segments)
     new_data = merge_segments(segments, exif)
 
     if isinstance(new_file, io.BytesIO):

piexif/_load.py

@@ -1,6 +1,7 @@
 import struct
 
 from ._common import *
+from ._exeptions import InvalidImageDataError
 from ._exif import *
 
 
@@ -90,7 +91,7 @@ def __init__(self, data):
                 with open(data, 'rb') as f:
                     self.tiftag = f.read()
             else:
-                raise ValueError("Given file is neither JPEG nor TIFF.")
+                raise InvalidImageDataError("Given file is neither JPEG nor TIFF.")
 
     def get_ifd_dict(self, pointer, ifd_name, read_unknown=False):
         ifd_dict = {}

piexif/_transplant.py

@@ -30,7 +30,6 @@ def transplant(exif_src, image, new_file=None):
             image_data = f.read()
         output_file = True
     segments = split_into_segments(image_data)
-    image_exif = get_exif_seg(segments)
     new_data = merge_segments(segments, exif)
 
     if isinstance(new_file, io.BytesIO):

tests/s_test.py

@@ -9,7 +9,7 @@
 
 from PIL import Image
 import piexif
-from piexif import _common, ImageIFD, ExifIFD, GPSIFD, TAGS
+from piexif import _common, ImageIFD, ExifIFD, GPSIFD, TAGS, InvalidImageDataError
 
 
 print("piexif version: {0}".format(piexif.VERSION))
@@ -596,7 +596,7 @@ def test_ExifReader_return_unknown(self):
         b2 = b"\x00\x01" + b"\xff\xff\x00\x00\x00\x00" + b"\x00\x00\x00\x00"
         er = piexif._load._ExifReader(b1 + b2)
         if er.tiftag[0:2] == b"II":
-            exifReader.endian_mark = "<"
+            er.endian_mark = "<"
         else:
             er.endian_mark = ">"
         ifd = er.get_ifd_dict(8, "0th", True)
@@ -610,7 +610,7 @@ def test_ExifReader_convert_value_fail(self):
             er.convert_value((None, None, None, None))
 
     def test_split_into_segments_fail1(self):
-        with self.assertRaises(ValueError):
+        with self.assertRaises(InvalidImageDataError):
             _common.split_into_segments(b"I'm not JPEG")
 
     def test_split_into_segments_fail2(self):