Encode HTML string before passing to storage

Works around an issue with boto3:

  https://github.com/jschneier/django-storages/issues/708

CHANGELOG.rst

@@ -9,6 +9,11 @@ and this project adheres to `Semantic Versioning`_.
 Unreleased
 ----------
 
+Fixed
+~~~~~
+
+* PDF generation failed with S3 storage due to incompatibility with boto3
+
 `2.7`_ - 2022-01-24
 -------------------
 

aleksis/core/util/pdf.py

@@ -79,7 +79,9 @@ def generate_pdf_from_template(
         processed_context = context
     html_template = render_to_string(template_name, processed_context, request)
 
-    file_object = PDFFile.objects.create(html_file=ContentFile(html_template, name="source.html"))
+    file_object = PDFFile.objects.create(
+        html_file=ContentFile(html_template.encode(), name="source.html")
+    )
 
     # As this method may be run in background and there is no request available,
     # we have to use a predefined URL from settings then