Handles different locales

app/controllers/groups_controller.rb

@@ -460,7 +460,10 @@ def handle_membership_request
     # find original membership request PM
     request_topic =
       Topic.find_by(
-        title: I18n.t("groups.request_membership_pm.title", group_name: group.name),
+        title:
+          (
+            I18n.t "groups.request_membership_pm.title", group_name: group.name, locale: user.locale
+          ),
         archetype: "private_message",
         user_id: user.id,
       )
@@ -479,7 +482,8 @@ def handle_membership_request
         current_user,
         post_type: Post.types[:regular],
         topic_id: request_topic.id,
-        raw: I18n.t("groups.request_accepted_pm.body", group_name: group.name),
+        raw:
+          (I18n.t "groups.request_accepted_pm.body", group_name: group.name, locale: user.locale),
         reply_to_post_number: 1,
         target_usernames: user.username,
         skip_validations: true,

spec/requests/groups_controller_spec.rb

@@ -2200,6 +2200,50 @@ def expect_type_to_return_right_groups(type, expected_group_ids)
         I18n.t("groups.request_accepted_pm.body", group_name: group.name).strip,
       )
     end
+
+    it "sends accepted membership request reply even if request is in another language" do
+      SiteSetting.allow_user_locale = true
+      other_user.update!(locale: "fr")
+
+      GroupRequest.create!(group: group, user: other_user)
+
+      # send the initial request PM
+      PostCreator.new(
+        other_user,
+        title:
+          (
+            I18n.t "groups.request_membership_pm.title",
+                   group_name: group.name,
+                   locale: other_user.locale
+          ),
+        raw: "*French accent* Please let me in!",
+        archetype: Archetype.private_message,
+        target_usernames: "#{user.username}",
+        skip_validations: true,
+      ).create!
+
+      topic = Topic.last
+
+      expect {
+        put "/groups/#{group.id}/handle_membership_request.json",
+            params: {
+              user_id: other_user.id,
+              accept: true,
+            }
+      }.to_not change { Topic.count }
+
+      expect(topic.archetype).to eq(Archetype.private_message)
+      expect(Topic.first.title).to eq(
+        I18n.t("groups.request_membership_pm.title", group_name: group.name),
+      )
+
+      post = Post.last
+      expect(post.topic_id).to eq(Topic.last.id)
+      expect(topic.posts.count).to eq(2)
+      expect(post.raw).to eq(
+        I18n.t("groups.request_accepted_pm.body", group_name: group.name).strip,
+      )
+    end
   end
 
   describe "#histories" do