item_location: add a parent_pocket() helper

that caches the parent pocket so you don't have to run
contained_where() everytime

src/avatar_action.cpp

@@ -1150,7 +1150,7 @@ void avatar_action::use_item( avatar &you, item_location &loc, std::string const
 
         // Get the parent pocket before the item is obtained.
         if( loc.has_parent() ) {
-            parent_pocket = loc.parent_item().get_item()->contained_where( *loc );
+            parent_pocket = loc.parent_pocket();
         }
 
         loc = loc.obtain( you, 1 );

src/character.cpp

@@ -9102,7 +9102,7 @@ ret_val<crush_tool_type> Character::can_crush_frozen_liquid( item_location loc )
 {
     crush_tool_type tool_type = CRUSH_NO_TOOL;
     bool success = false;
-    if( !loc.has_parent() || !loc.parent_item()->contained_where( *loc )->get_pocket_data()->rigid ) {
+    if( !loc.has_parent() || !loc.parent_pocket()->get_pocket_data()->rigid ) {
         tool_type = CRUSH_HAMMER;
         success = has_quality( qual_HAMMER );
     } else {

src/character_inventory.cpp

@@ -89,7 +89,7 @@ void Character::handle_contents_changed( const std::vector<item_location> &conta
         if( loc.has_parent() ) {
             item_location parent_loc = loc.parent_item();
             item_loc_with_depth parent( parent_loc );
-            item_pocket *const pocket = parent_loc->contained_where( *loc );
+            item_pocket *const pocket = loc.parent_pocket();
             pocket->unseal();
             bool exists = false;
             auto it = sorted_containers.lower_bound( parent );

src/contents_change_handler.cpp

@@ -12,7 +12,7 @@ void contents_change_handler::unseal_pocket_containing( const item_location &loc
 {
     if( loc.has_parent() ) {
         item_location parent = loc.parent_item();
-        item_pocket *const pocket = parent->contained_where( *loc );
+        item_pocket *const pocket = loc.parent_pocket();
         if( pocket ) {
             // on_contents_changed restacks the pocket and should be called later
             // in Character::handle_contents_changed

src/game.cpp

@@ -2135,7 +2135,7 @@ int game::inventory_item_menu( item_location locThisItem,
                     oThisItem.is_favorite = !oThisItem.is_favorite;
                     if( locThisItem.has_parent() ) {
                         item_location parent = locThisItem.parent_item();
-                        item_pocket *const pocket = parent->contained_where( oThisItem );
+                        item_pocket *const pocket = locThisItem.parent_pocket();
                         if( pocket ) {
                             pocket->restack();
                         } else {

src/game_inventory.cpp

@@ -707,7 +707,7 @@ class comestible_inventory_preset : public inventory_selector_preset
                 item_location temp = loc;
                 // check if at least one parent container is sealed
                 while( temp.has_parent() ) {
-                    item_pocket *pocket = temp.parent_item()->contained_where( *temp.get_item() );
+                    item_pocket *pocket = temp.parent_pocket();
                     if( pocket->sealed() ) {
                         sealed = _( "sealed" );
                         break;
@@ -795,7 +795,7 @@ class comestible_inventory_preset : public inventory_selector_preset
             } else if( time == 0_turns ) {
                 return 4;
             } else if( loc.has_parent() &&
-                       loc.parent_item()->contained_where( *loc )->spoil_multiplier() == 0.0f ) {
+                       loc.parent_pocket()->spoil_multiplier() == 0.0f ) {
                 return 3;
             } else {
                 return 2;

src/handle_action.cpp

@@ -2380,7 +2380,6 @@ bool game::do_regular_action( action_id &act, avatar &player_character,
                 } else {
                     drop_in_direction( *pnt );
                 }
-                drop_in_direction( *pnt );
             }
             break;
         case ACTION_BIONICS:

src/inventory_ui.cpp

@@ -177,7 +177,7 @@ bool is_worn_ablative( item_location const &container, item_location const &chil
     // if the item is in an ablative pocket then put it with the item it is in
     // first do a short circuit test if the parent has ablative pockets at all
     return container->is_ablative() && container->is_worn_by_player() &&
-           container->contained_where( *child )->get_pocket_data()->ablative;
+           child.parent_pocket()->get_pocket_data()->ablative;
 }
 
 /** The maximum distance from the screen edge, to snap a window to it */
@@ -508,11 +508,10 @@ bool inventory_entry::is_hidden( cata::optional<bool> const &hide_entries_overri
         return *hide_entries_override;
     }
     while( item.has_parent() && item != topmost_parent ) {
-        item_location parent = item.parent_item();
-        if( parent.get_item()->contained_where( *item )->settings.is_collapsed() ) {
+        if( item.parent_pocket()->settings.is_collapsed() ) {
             return true;
         }
-        item = parent;
+        item = item.parent_item();
     }
     return false;
 }

src/item_location.cpp

@@ -85,6 +85,9 @@ class item_location::impl
         virtual item_location parent_item() const {
             return item_location();
         }
+        virtual item_pocket *parent_pocket() const {
+            return nullptr;
+        }
         virtual tripoint position() const = 0;
         virtual std::string describe( const Character * ) const = 0;
         virtual item_location obtain( Character &, int ) = 0;
@@ -564,6 +567,7 @@ class item_location::impl::item_in_container : public item_location::impl
 {
     private:
         item_location container;
+        mutable item_pocket *container_pkt = nullptr;
 
         // figures out the index for the item, which is where it is in the total list of contents
         // note: could be a better way of handling this?
@@ -588,6 +592,18 @@ class item_location::impl::item_in_container : public item_location::impl
             return container;
         }
 
+        item_pocket *parent_pocket() const override {
+            if( container_pkt == nullptr ) {
+                std::vector<item_pocket *> const pkts = parent_item()->get_all_standard_pockets();
+                if( pkts.size() == 1 ) {
+                    container_pkt = pkts.front();
+                } else {
+                    container_pkt = parent_item()->contained_where( *target() );
+                }
+            }
+            return container_pkt;
+        }
+
         item_in_container( const item_location &container, item *which ) :
             impl( which ), container( container ) {}
 
@@ -718,11 +734,11 @@ class item_location::impl::item_in_container : public item_location::impl
         }
 
         units::volume volume_capacity() const override {
-            return container->contained_where( *target() )->remaining_volume();
+            return parent_pocket()->remaining_volume();
         }
 
         units::mass weight_capacity() const override {
-            return container->contained_where( *target() )->remaining_weight();
+            return parent_pocket()->remaining_weight();
         }
 
         bool check_parent_capacity_recursive() const override {
@@ -846,6 +862,14 @@ item_location item_location::parent_item() const
     return item_location::nowhere;
 }
 
+item_pocket *item_location::parent_pocket() const
+{
+    if( where() == type::container ) {
+        return ptr->parent_pocket();
+    }
+    return nullptr;
+}
+
 bool item_location::has_parent() const
 {
     if( where() == type::container ) {
@@ -861,7 +885,7 @@ bool item_location::parents_can_contain_recursive( item *it ) const
     }
 
     item_location parent = parent_item();
-    item_pocket *pocket = parent->contained_where( *get_item() );
+    item_pocket *pocket = parent_pocket();
 
     if( pocket->can_contain( *it ).success() ) {
         return parent.parents_can_contain_recursive( it );
@@ -877,7 +901,7 @@ int item_location::max_charges_by_parent_recursive( const item &it ) const
     }
 
     item_location parent = parent_item();
-    item_pocket *pocket = parent->contained_where( *get_item() );
+    item_pocket *pocket = parent_pocket();
 
     return std::min( { it.charges_per_volume( pocket->remaining_volume() ),
                        it.charges_per_weight( pocket->remaining_weight() ),

src/item_location.h

@@ -14,6 +14,7 @@ class character_id;
 class JsonObject;
 class JsonOut;
 class item;
+class item_pocket;
 class map_cursor;
 class vehicle_cursor;
 class talker;
@@ -106,6 +107,7 @@ class item_location
 
         /** returns the parent item, or an invalid location if it has no parent */
         item_location parent_item() const;
+        item_pocket *parent_pocket() const;
 
         /** returns true if the item is in the inventory of the given character **/
         bool held_by( Character const &who ) const;

tests/unseal_and_spill_test.cpp

@@ -256,7 +256,7 @@ void match( Parent &&parent, Container &&contents,
                     match( content_loc, content_result );
                     item_location container = container_from_parent( parent );
                     if( container ) {
-                        item_pocket *pocket = container->contained_where( *content );
+                        item_pocket *pocket = content_loc.parent_pocket();
                         REQUIRE( pocket );
                         CHECK( content_result.parent_pocket_sealed == pocket->sealed() );
                     }