From 586bbe3b8ca2babfc7b4f02a6e5887b47e2cc9cd Mon Sep 17 00:00:00 2001
From: Joseph Wright <joseph.wright@morningstar2.co.uk>
Date: Tue, 7 Jun 2022 09:54:29 +0100
Subject: [PATCH] More space work

---
 base/lttemplate.dtx | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/base/lttemplate.dtx b/base/lttemplate.dtx
index 898415fe8..d3e2f0af6 100644
--- a/base/lttemplate.dtx
+++ b/base/lttemplate.dtx
@@ -720,7 +720,11 @@
                   {
                     \tl_set:Nx \l_@@_keytype_tl
                       { \tl_trim_spaces:n {##1} }
-                    \tl_set:Nx \l_@@_keytype_arg_tl { \use:n ####2 }
+                    \tl_if_blank:nF {####2}
+                      {
+                        \tl_set:Nx \l_@@_keytype_arg_tl
+                          { \use:n ####2 }
+                      }
                     \seq_map_break:
                   }
               }