X-Git-Url: https://git.mdrn.pl/librarian.git/blobdiff_plain/d8393802a7cb8d84a3b3c989ea30b4ba21d9a8da..aeb2a02ce8d5bc789e8e23f5859c7e96afa6da0b:/librarian/formats/cover/evens/__init__.py

diff --git a/librarian/formats/cover/evens/__init__.py b/librarian/formats/cover/evens/__init__.py
index e07f78b..35ef84a 100644
--- a/librarian/formats/cover/evens/__init__.py
+++ b/librarian/formats/cover/evens/__init__.py
@@ -27,6 +27,9 @@ class EvensCover(Cover):
             raise BuildError('No cover specified (metadata field relation.coverimage.url empty)')
         if cover_url.startswith('file://'):
             cover_url = ctx.files_path + urllib.quote(cover_url[7:])
+        IMG_EXT = ('png', 'jpg', 'jpeg')
+        if '.' not in self.background_img or self.background_img.rsplit('.')[1].lower() not in IMG_EXT:
+            raise BuildError('Wrong cover format, should be PNG or JPG')
         try:
             self.background_img = urlopen(cover_url)
         except URLError: