Bug: Enable template tag `richtext` to convert lazy text strings (#11901)

Fixes #11900

CHANGELOG.txt

@@ -8,6 +8,7 @@ Changelog
  * Support a `HOSTNAMES` parameter on `WAGTAILFRONTENDCACHE` to define which hostnames a backend should respond to (Jake Howard, sponsored by Oxfam America)
  * Refactor redirects edit view to use the generic `EditView` and breadcrumbs (Rohit Sharma)
  * Fix: Make `WAGTAILIMAGES_CHOOSER_PAGE_SIZE` setting functional again (Rohit Sharma)
+ * Fix: Enable `richtext` template tag to convert lazy translation values (Benjamin Bach)
 
 
 6.1 (xx.xx.xxxx) - IN DEVELOPMENT

docs/releases/6.2.md

@@ -21,6 +21,7 @@ depth: 1
 ### Bug fixes
 
  * Make `WAGTAILIMAGES_CHOOSER_PAGE_SIZE` setting functional again (Rohit Sharma)
+ * Enable `richtext` template tag to convert lazy translation values (Benjamin Bach)
 
 
 ### Documentation

wagtail/templatetags/wagtailcore_tags.py

@@ -3,6 +3,7 @@ from django.shortcuts import resolve_url
 from django.template.defaulttags import token_kwargs
 from django.template.loader import render_to_string
 from django.utils.encoding import force_str
+from django.utils.functional import Promise
 from django.utils.html import conditional_escape
 
 from wagtail import VERSION, __version__
@@ -120,6 +121,8 @@ def richtext(value):
     elif value is None:
         html = ""
     else:
+        if isinstance(value, Promise):
+            value = str(value)
         if isinstance(value, str):
             html = expand_db_html(value)
         else:

wagtail/tests/tests.py

@@ -9,6 +9,7 @@ from django.test import TestCase
 from django.test.utils import override_settings
 from django.urls.exceptions import NoReverseMatch
 from django.utils.safestring import SafeString
+from django.utils.translation import gettext_lazy
 
 from wagtail.coreutils import (
     get_dummy_request,
@@ -536,6 +537,10 @@ class TestRichtextTag(TestCase):
         self.assertEqual(result, "Hello world!")
         self.assertIsInstance(result, SafeString)
 
+    def test_call_with_lazy(self):
+        result = richtext(gettext_lazy("test"))
+        self.assertEqual(result, "test")
+
     def test_call_with_none(self):
         result = richtext(None)
         self.assertEqual(result, "")