FIX: Use default locale for edit reason when owner of post gets changed

app/models/post.rb

@@ -498,16 +498,22 @@ class Post < ActiveRecord::Base
   def set_owner(new_user, actor, skip_revision = false)
     return if user_id == new_user.id
 
-    edit_reason = I18n.t('change_owner.post_revision_text',
+    edit_reason = I18n.with_locale(SiteSetting.default_locale) do
+      I18n.t('change_owner.post_revision_text',
              old_user: (self.user.username_lower rescue nil) || I18n.t('change_owner.deleted_user'),
              new_user: new_user.username_lower
       )
-    revise(actor, { raw: self.raw, user_id: new_user.id, edit_reason: edit_reason }, bypass_bump: true, skip_revision: skip_revision)
+    end
+
+    revise(
+      actor,
+      { raw: self.raw, user_id: new_user.id, edit_reason: edit_reason },
+      bypass_bump: true, skip_revision: skip_revision
+    )
 
     if post_number == topic.highest_post_number
       topic.update_columns(last_post_user_id: new_user.id)
     end
-
   end
 
   before_create do

spec/models/post_spec.rb

@@ -919,6 +919,23 @@ describe Post do
       expect(post.user).to eq(coding_horror)
       expect(post.revisions.size).to eq(0)
     end
+
+    it "uses default locale for edit reason" do
+      I18n.locale = 'de'
+      old_username = post.user.username_lower
+
+      post.set_owner(coding_horror, Discourse.system_user)
+      post.reload
+
+      expected_reason = I18n.with_locale(SiteSetting.default_locale) do
+        I18n.t('change_owner.post_revision_text',
+               old_user: old_username,
+               new_user: coding_horror.username_lower
+        )
+      end
+
+      expect(post.edit_reason).to eq(expected_reason)
+    end
   end
 
   describe ".rebake_old" do