Expand variable contents when passing \KeyValue content (fixes #1486)

base/changes.txt

@@ -5,6 +5,11 @@ hotfixes). It is provided for convenience only. It therefore makes no claims
 to completeness or accuracy and it contains some references to files that are
 not part of the distribution.
 ================================================================================
+
+2024-10-07 Joseph Wright <[email protected]>
+ * lttemplates.dtx
+ Correct passing of token list content using \KeyValue
+
 2024-10-02 Ulrike Fischer <[email protected]>
  * lttagging.dtx: restore also paratagging in the para/restore socket, 
  see https://github.com/latex3/tagging-project/issues/723
@@ -17,7 +22,6 @@ not part of the distribution.
  * lttagging.dtx: declare tagging sockets for floats and caption.
 
 2024-09-15 Joseph Wright <[email protected]>
-
  * lttemplates-doc.tex, lttemplates-code.tex:
  New files
  * clsguide.tex

base/lttemplates.dtx

@@ -2098,30 +2098,43 @@
 % \end{macro}
 %
 % \begin{macro}{\@@_assign_variable:}
-% \begin{macro}{\@@_assign_variable:N, \@@_assign_variable:c}
+% \begin{macro}{\@@_assign_variable:n}
 % A general-purpose function for all of the other assignments.
 % As long as the value is not coming from another variable, the stored
-% value is simply transferred for output.
+% value is simply transferred for output. We use \texttt{V}-type expansion
+% for the \cs{KeyValue} case: for token lists this is essential, whilst
+% for register-based variables, it does no harm and avoids needing a
+% low-level test.
 % \begin{macrocode}
 \cs_new_protected:Npn \@@_assign_variable:
  {
- \@@_assign_variable:c
+ \exp_args:Ne \@@_assign_variable:n
  {
- \@@_map_var_type: _
- \bool_if:NT \l_@@_global_bool { g } set:Nn
+ \@@_map_var_type:
+ _
+ \bool_if:NT \l_@@_global_bool { g } 
+ set:N
  }
  }
-\cs_new_protected:Npn \@@_assign_variable:N #1
+\cs_new_protected:Npn \@@_assign_variable:n #1
  {
- \@@_if_key_value:VT \l_@@_value_tl
- { \@@_key_to_value: }
- \tl_put_right:Ne \l_@@_assignments_tl
+ \@@_if_key_value:VTF \l_@@_value_tl
  {
- #1 \exp_not:V \l_@@_var_tl
- { \exp_not:V \l_@@_value_tl }
+ \@@_key_to_value:
+ \tl_put_right:Ne \l_@@_assignments_tl
+ {
+ \exp_not:c { #1 V } \exp_not:V \l_@@_var_tl
+ \exp_not:V \l_@@_value_tl
+ }
+ }
+ {
+ \tl_put_right:Ne \l_@@_assignments_tl
+ {
+ \exp_not:c { #1 n } \exp_not:V \l_@@_var_tl
+ { \exp_not:V \l_@@_value_tl }
+ }
  }
  }
-\cs_generate_variant:Nn \@@_assign_variable:N { c }
 % \end{macrocode}
 % \end{macro}
 % \end{macro}

base/testfiles-lttemplates/lttemplates005.lvt

@@ -52,17 +52,20 @@
  dim-b : length = \KeyValue { dim-a } ,
  tl-a : tokenlist = abc ,
  tl-b : tokenlist = \KeyValue { tl-a } ,
+ tl-c : tokenlist = \KeyValue { tl-a } ,
  }
  \DeclareTemplateCode { test } { std2 } { 0 }
  {
  dim-a = global \g_tmpa_dim ,
  dim-b = \l_tmpb_dim ,
  tl-a = \l_tmpa_tl ,
- tl-b = \l_tmpb_tl
+ tl-b = \l_tmpb_tl ,
+ tl-c = \l_tmpa_tl
  }
  {
  \typeout { \dim_use:N \l_tmpb_dim }
  \typeout { \tl_use:N \l_tmpb_tl }
+ \typeout { \tl_use:N \l_tmpa_tl }
  }
  \DeclareInstance { test } { run } { std2 } { }
 

base/testfiles-lttemplates/lttemplates005.tlg

@@ -16,6 +16,7 @@ TEST 2: Key values with global
 ============================================================
 10.0pt
 abc
+abc
 ============================================================
 ============================================================
 TEST 3: Key values for booleans