fix(2447): avoid failed validation of a section form to clear the rest of forms

Author: ycanales

users/tests/test_v3_profile_edit.py

@@ -146,7 +146,12 @@ def test_v3_update_details_blank_country_clears_it(user, tp):
 
 @waffle.testutils.override_flag("v3", active=True)
 def test_v3_update_details_duplicate_username_shows_inline_error(user, tp):
+    """Only the details section is submitted, so hide_github (owned by a
+    different section's form) is absent from the POST. A validation failure
+    here must not blank out that other section's displayed state."""
     baker.make("users.User", display_name="taken-name")
+    user.hide_github_activity = True
+    user.save()
     with tp.login(user):
         response = tp.post(
             f"{tp.reverse('profile-account')}?edit=true",
@@ -159,6 +164,7 @@ def test_v3_update_details_duplicate_username_shows_inline_error(user, tp):
         tp.response_200(response)
         form = response.context["user_profile_form"]
         assert "This username is already taken" in form.errors["username"]
+        assert form["hide_github"].value() is True
     user.refresh_from_db()
     assert user.display_name != "taken-name"
 

users/views.py

@@ -587,11 +587,39 @@ def post_v3(self, request, *args, **kwargs):
             return HttpResponseRedirect(edit_url)
         section_fields, save_method_name = self.V3_EDIT_SECTIONS[section_key]
 
+        # Each section is submitted independently, so request.POST only
+        # carries this section's fields; every other field on the shared
+        # form would otherwise be treated as blank/unchecked when
+        # re-rendering after a validation error. Fill those in from the
+        # user's current values so a failed save on one section doesn't
+        # wipe the displayed state of the others.
+        initial = self.get_v3_edit_initial()
+        data = request.POST.copy()
+        for field_name, value in initial.items():
+            if field_name in data or field_name in section_fields:
+                continue
+            if value is True:
+                data[field_name] = "on"
+            elif value in (False, None):
+                continue
+            elif isinstance(value, (list, tuple)):
+                valid_choices = {
+                    choice
+                    for choice, _ in getattr(
+                        V3UserProfileForm.base_fields.get(field_name), "choices", []
+                    )
+                }
+                values = [v for v in value if v in valid_choices]
+                if values:
+                    data.setlist(field_name, values)
+            else:
+                data[field_name] = value
+
         form = V3UserProfileForm(
-            request.POST,
+            data,
             user=request.user,
             user_links=request.user.profile_links,
-            initial=self.get_v3_edit_initial(),
+            initial=initial,
         )
         # Only the submitted section's fields are validated; the other fields
         # share this form but have no save handler yet, so neither their