Embeds: Fixed crash when no HTML field is sent back from the embed provider

wagtail/wagtailembeds/embeds.py

@@ -162,6 +162,10 @@ def get_embed(url, max_width=None, finder=None):
     except (TypeError, ValueError):
         embed_dict['height'] = None
 
+    # Make sure html field is valid
+    if 'html' not in embed_dict or not embed_dict['html']:
+        embed_dict['html'] = ''
+
     # Create database record
     embed, created = Embed.objects.get_or_create(
         url=url,

wagtail/wagtailembeds/tests.py

@@ -79,6 +79,19 @@ class TestEmbeds(TestCase):
         # Width must be set to None
         self.assertEqual(embed.width, None)
 
+    def test_no_html(self) :
+        def no_html_finder(url, max_width=None):
+            """
+            A finder which returns everything but HTML
+            """
+            embed = self.dummy_finder(url, max_width)
+            embed['html'] = None
+            return embed
+
+        embed = get_embed('www.test.com/1234', max_width=400, finder=no_html_finder)
+
+        self.assertEqual(embed.html, '')
+
 
 class TestChooser(TestCase, WagtailTestUtils):
     def setUp(self):