Prevent Draftail from crashing on links to missing pages

wagtail/admin/rich_text/converters/html_to_contentstate.py

@@ -206,7 +206,12 @@ class PageLinkElementHandler(LinkElementHandler):
         try:
             page = Page.objects.get(id=attrs['id']).specific
         except Page.DoesNotExist:
-            return {}
+            # retain ID so that it's still identified as a page link (albeit a broken one)
+            return {
+                'id': int(attrs['id']),
+                'url': None,
+                'parentId': None
+            }
 
         parent_page = page.get_parent()
 

wagtail/admin/tests/test_contentstate.py

@@ -326,7 +326,9 @@ class TestHtmlToContentState(TestCase):
             'entityMap': {
                 '0': {
                     'mutability': 'MUTABLE', 'type': 'LINK',
-                    'data': {}
+                    'data': {
+                        'id': 9999, 'url': None, 'parentId': None,
+                    }
                 }
             },
             'blocks': [