fixup! cache available recipe list in craft menu

src/character.h

@@ -3517,7 +3517,7 @@ class Character : public Creature, public visitable
         /**
           * Return all available recipes for any member of `this` crafter's group. Using `this` inventory.
           */
-        recipe_subset get_group_available_recipes() const;
+        recipe_subset &get_group_available_recipes() const;
         /**
           * Returns the set of book types in crafting_inv that provide the
           * given recipe.
@@ -4124,7 +4124,9 @@ class Character : public Creature, public visitable
         // is recalculated every turn in Character::recalculate_enchantment_cache
         pimpl<enchant_cache> enchantment_cache;
 
-    public:
+    private:
+        /* cached recipes, which are invalidated if the turn changes */
+        mutable time_point cached_recipe_turn;
         pimpl<recipe_subset> cached_recipe_subset;
 };
 

src/character_crafting.cpp

@@ -6,6 +6,7 @@
 #include <utility>
 #include <vector>
 
+#include "cached_options.h"
 #include "character.h"
 #include "inventory.h"
 #include "item.h"
@@ -181,21 +182,20 @@ recipe_subset Character::get_available_recipes( const inventory &crafting_inv,
     return res;
 }
 
-recipe_subset Character::get_group_available_recipes() const
+recipe_subset &Character::get_group_available_recipes() const
 {
-    recipe_subset res;
-
-    if( cached_recipe_subset->size() > 0 ) {
+    if( !test_mode && calendar::turn == cached_recipe_turn && cached_recipe_subset->size() > 0 ) {
         return *cached_recipe_subset;
     }
 
+    cached_recipe_turn = calendar::turn;
+    cached_recipe_subset->clear();
+
     for( const Character *guy : get_crafting_group() ) {
-        res.include( guy->get_available_recipes( crafting_inventory() ) );
+        cached_recipe_subset->include( guy->get_available_recipes( crafting_inventory() ) );
     }
 
-    cached_recipe_subset->include( res );
-
-    return res;
+    return *cached_recipe_subset;
 }
 
 std::set<itype_id> Character::get_books_for_recipe( const inventory &crafting_inv,

src/crafting_gui.cpp

@@ -2031,8 +2031,6 @@ std::pair<Character *, const recipe *> select_crafter_and_crafting_recipe( int &
         }
     } while( !done );
 
-    crafter->cached_recipe_subset->clear();
-
     return { crafter, chosen };
 }