fix(email): use a custom engine for plaintext emails

src/sentry/utils/email/message_builder.py

@@ -11,7 +11,9 @@
 
 import lxml.html
 import toronado
+from django.conf import settings
 from django.core.mail import EmailMultiAlternatives
+from django.template.engine import Engine
 from django.utils.encoding import force_str
 
 from sentry import options
@@ -132,8 +134,14 @@ def __render_html_body(self) -> str | None:
         return inline_css(html_body)
 
     def __render_text_body(self) -> str:
+        # Create a clone of the default Django templater with autoescape disabled.
+        # TODO: cache this?
+        params = settings.TEMPLATES[0].copy()
+        params["OPTIONS"]["autoescape"] = False
+        engine = Engine(params["DIRS"], params["APP_DIRS"], **params["OPTIONS"])
+
         if self.template:
-            body: str = render_to_string(self.template, self.context)
+            body: str = render_to_string(self.template, self.context, engine=engine)
             return body
         return self._txt_body
 

src/sentry/web/helpers.py

@@ -5,7 +5,8 @@
 from typing import Any
 
 from django.http import HttpRequest, HttpResponse
-from django.template import loader
+from django.template import Context, loader
+from django.template.engine import Engine
 from django.utils import timezone
 
 from sentry.utils.dates import AVAILABLE_TIMEZONES
@@ -17,6 +18,7 @@ def render_to_string(
     template: Sequence[str] | str,
     context: Mapping[str, Any] | None = None,
     request: HttpRequest | None = None,
+    engine: Engine | None = None,
 ) -> str:
     if context is None:
         context = dict()
@@ -26,7 +28,12 @@ def render_to_string(
     if "timezone" in context and context["timezone"] in AVAILABLE_TIMEZONES:
         timezone.activate(context["timezone"])
 
-    rendered = loader.render_to_string(template, context=context, request=request)
+    if engine is None:
+        rendered = loader.render_to_string(template, context=context, request=request)
+    else:
+        template_compiled = engine.get_template(template)
+        rendered = template_compiled.render(Context(context, autoescape=engine.autoescape))
+
     timezone.deactivate()
 
     return rendered