fixes in thumbnails and watermarks

batiskaf/jinja2_ext/thumbnails.py

@@ -1,7 +1,11 @@
 from easy_thumbnails.files import get_thumbnailer
+from easy_thumbnails.exceptions import InvalidImageFormatError
 
 
 def thumbnail(img, size='420x420'):
     weight, height = size.split('x')
     options = {'size': (int(weight), int(height)), 'background': '#fff'}
-    return get_thumbnailer(img).get_thumbnail(options)
+    try:
+        return get_thumbnailer(img).get_thumbnail(options)
+    except (ValueError, InvalidImageFormatError):
+        return {'url': ''}

batiskaf/jinja2_ext/watermarks.py

@@ -3,4 +3,6 @@ from watermarker import core
 
 
 def watermark(url, wm):
+    if url is None:
+        url = ''
     return core.watermark(url, wm)

store/models.py

@@ -209,7 +209,7 @@ class Product(models.Model):
         try:
             return self.images.order_by('-is_main')[0].image
         except:
-            return None
+            return {'url': ''}
 
     def in_stock(self):
         return self.variations.filter(in_stock__gt=0).count()