Correct behaviour of reversed and pair declarations

latex3 · Mar 30, 2023 · c0a0908 · c0a0908
1 parent 33ad404
commit c0a0908
Showing 1 changed file with 24 additions and 13 deletions.
diff --git a/base/lthooks.dtx b/base/lthooks.dtx
@@ -2891,13 +2891,12 @@
   { \@@_normalize_hook_args:Nn \@@_new_reversed:nn {#1} {#2} }
 \cs_new_protected:Npn \@@_new_reversed:nn #1 #2
   {
-    \@@_new:nn {#1} {#2}
-%    \end{macrocode}
-%    If the hook already exists the above will generate an error
-%    message, so the next line should be executed (but it is --- too
-%    bad).
-%    \begin{macrocode}
-    \tl_gset:cn { g_@@_#1_reversed_tl } { - }
+    \@@_if_declared:nTF {#1}
+      { \msg_error:nnn { hooks } { exists } {#1} }
+      {
+        \@@_new:nn {#1} {#2}
+        \tl_gset:cn { g_@@_#1_reversed_tl } { - }
+      }
   }
 %<latexrelease>\EndIncludeInRelease
 %    \end{macrocode}
@@ -2926,21 +2925,33 @@
 %<latexrelease>\IncludeInRelease{2023/06/01}{\hook_new_pair_with_args:nnn}
 %<latexrelease>                 {Hooks~with~args}
 \cs_new_protected:Npn \hook_new_pair:nn #1#2
-  {
-    \hook_new:n {#1}
-    \hook_new_reversed:n {#2}
-  }
+  { \@@_normalize_hook_args:Nnn \@@_new_pair:nnn {#1} {#2} { 0 } }
 \cs_new_protected:Npn \hook_new_pair_with_args:nnn #1#2#3
+  { \@@_normalize_hook_args:Nnn \@@_new_pair:nnn {#1} {#2} {#3} }
+\cs_new_protected:Npn \@@_new_pair:nnn #1 #2 #3
   {
-    \hook_new_with_args:nn {#1} {#3}
-    \hook_new_reversed_with_args:nn {#2} {#3}
+    \@@_if_declared:nTF {#1}
+      { \msg_error:nnn { hooks } { exists } {#1} }
+      {
+        \@@_if_declared:nTF {#2}
+          { \msg_error:nnn { hooks } { exists } {#2} }
+          {
+            \@@_new:nn {#1} {#3}
+            \@@_new_reversed:nn {#2} {#3}
+          }
+      }
   }
 %<latexrelease>\EndIncludeInRelease
 %    \end{macrocode}
 %
 %    \begin{macrocode}
 %<latexrelease>\IncludeInRelease{2020/10/01}{\hook_new_pair_with_args:nnn}
 %<latexrelease>                 {Hooks~with~args}
+%<latexrelease>\cs_gset_protected:Npn \hook_new_pair:nn #1#2
+%<latexrelease>  {
+%<latexrelease>    \hook_new:n {#1}
+%<latexrelease>    \hook_new_reversed:n {#2}
+%<latexrelease>  }
 %<latexrelease>\cs_gset_protected:Npn \hook_new_pair_with_args:nnn #1#2#3
 %<latexrelease>  { }
 %<latexrelease>\EndIncludeInRelease