Merge pull request #199 from thekad/bug/empty-iso-speed-ratings

Empty ISO speed ratings

sigal/image.py

@@ -270,7 +270,7 @@ def get_exif_tags(data):
         else:
             logger.info('Unknown format for ExposureTime: %r', exptime)
 
-    if 'ISOSpeedRatings' in data:
+    if 'ISOSpeedRatings' in data and data['ISOSpeedRatings']:
         if isinstance(data['ISOSpeedRatings'], tuple):
             # Pillow == 3.0
             simple['iso'] = data['ISOSpeedRatings'][0]

tests/test_image.py

@@ -137,6 +137,20 @@ def test_get_exif_tags():
     assert 'gps' not in simple
 
 
+def test_iso_speed_ratings():
+    data = {'ISOSpeedRatings': ()}
+    simple = get_exif_tags(data)
+    assert 'iso' not in simple
+
+    data = {'ISOSpeedRatings': None}
+    simple = get_exif_tags(data)
+    assert 'iso' not in simple
+
+    data = {'ISOSpeedRatings': 125}
+    simple = get_exif_tags(data)
+    assert 'iso' in simple
+
+
 def test_null_exposure_time():
     data = {'ExposureTime': (0, 0)}
     simple = get_exif_tags(data)