FIX: Couldn't like staff when allow_flagging_staff was set

lib/guardian/post_guardian.rb

@@ -22,7 +22,9 @@ module PostGuardian
     result = if authenticated? && post && !@user.anonymous?
 
       # post made by staff, but we don't allow staff flags
-      return false if !SiteSetting.allow_flagging_staff? && post.user.staff?
+      return false if is_flag &&
+        (!SiteSetting.allow_flagging_staff?) &&
+        post.user.staff?
 
       return false if [:notify_user, :notify_moderators].include?(action_key) &&
         !SiteSetting.enable_personal_messages?

spec/components/guardian_spec.rb

@@ -83,6 +83,12 @@ describe Guardian do
       expect(Guardian.new(user).post_can_act?(staff_post, :spam)).to eq(false)
     end
 
+    it "allows liking of staff when allow_flagging_staff is false" do
+      SiteSetting.allow_flagging_staff = false
+      staff_post = Fabricate(:post, user: Fabricate(:moderator))
+      expect(Guardian.new(user).post_can_act?(staff_post, :like)).to eq(true)
+    end
+
     it "returns false when liking yourself" do
       expect(Guardian.new(post.user).post_can_act?(post, :like)).to be_falsey
     end