move has_rotten_away from map to item

src/item.cpp

@@ -8305,6 +8305,39 @@ bool item::detonate( const tripoint &p, std::vector<item> &drops )
     return false;
 }
 
+bool item::has_rotten_away( const tripoint &pnt )
+{
+    if( is_corpse() && goes_bad() ) {
+        process_temperature_rot( 1, pnt, nullptr );
+        return get_rot() > 10_days && !can_revive();
+    } else if( goes_bad() ) {
+        process_temperature_rot( 1, pnt, nullptr );
+        return has_rotten_away();
+    } else if( type->container && type->container->preserves ) {
+        // Containers like tin cans preserves all items inside, they do not rot at all.
+        return false;
+    } else if( type->container && type->container->seals ) {
+        // Items inside rot but do not vanish as the container seals them in.
+        for( auto &c : contents ) {
+            if( c.goes_bad() ) {
+                c.process_temperature_rot( 1, pnt, nullptr );
+            }
+        }
+        return false;
+    } else {
+        // Check and remove rotten contents, but always keep the container.
+        for( auto it = contents.begin(); it != contents.end(); ) {
+            if( it->has_rotten_away( pnt ) ) {
+                it = contents.erase( it );
+            } else {
+                ++it;
+            }
+        }
+
+        return false;
+    }
+}
+
 bool item_ptr_compare_by_charges( const item *left, const item *right )
 {
     if( left->contents.empty() ) {

src/item.h

@@ -720,6 +720,13 @@ class item : public visitable<item>
          * @param mod How many charges should be removed.
          */
         void mod_charges( int mod );
+        /**
+         * Whether the item has to be removed as it has rotten away completely. May change the item as it calls process_temperature_rot()
+         * @param pnt The *absolute* position of the item in the world (see @ref map::getabs),
+         * used for rot calculation.
+         * @return true if the item has rotten away and should be removed, false otherwise.
+         */
+        bool has_rotten_away( const tripoint &pnt );
 
         /**
          * Accumulate rot of the item since last rot calculation.

src/map.cpp

@@ -6687,45 +6687,12 @@ void map::loadn( const tripoint &grid, const bool update_vehicles )
     abs_sub.z = old_abs_z;
 }
 
-bool map::has_rotten_away( item &itm, const tripoint &pnt ) const
-{
-    if( itm.is_corpse() && itm.goes_bad() ) {
-        itm.process_temperature_rot( 1, pnt, nullptr );
-        return itm.get_rot() > 10_days && !itm.can_revive();
-    } else if( itm.goes_bad() ) {
-        itm.process_temperature_rot( 1, pnt, nullptr );
-        return itm.has_rotten_away();
-    } else if( itm.type->container && itm.type->container->preserves ) {
-        // Containers like tin cans preserves all items inside, they do not rot at all.
-        return false;
-    } else if( itm.type->container && itm.type->container->seals ) {
-        // Items inside rot but do not vanish as the container seals them in.
-        for( auto &c : itm.contents ) {
-            if( c.goes_bad() ) {
-                c.process_temperature_rot( 1, pnt, nullptr );
-            }
-        }
-        return false;
-    } else {
-        // Check and remove rotten contents, but always keep the container.
-        for( auto it = itm.contents.begin(); it != itm.contents.end(); ) {
-            if( has_rotten_away( *it, pnt ) ) {
-                it = itm.contents.erase( it );
-            } else {
-                ++it;
-            }
-        }
-
-        return false;
-    }
-}
-
 template <typename Container>
 void map::remove_rotten_items( Container &items, const tripoint &pnt )
 {
     const tripoint abs_pnt = getabs( pnt );
     for( auto it = items.begin(); it != items.end(); ) {
-        if( has_rotten_away( *it, abs_pnt ) ) {
+        if( it->has_rotten_away( abs_pnt ) ) {
             if( it->is_comestible() ) {
                 rotten_item_spawn( *it, pnt );
             }

src/map.h

@@ -1481,14 +1481,6 @@ class map
          * Hacks in missing roofs. Should be removed when 3D mapgen is done.
          */
         void add_roofs( const tripoint &grid );
-        /**
-         * Whether the item has to be removed as it has rotten away completely.
-         * @param itm Item to check for rotting
-         * @param pnt The *absolute* position of the item in the world (not just on this map!),
-         * used for rot calculation.
-         * @return true if the item has rotten away and should be removed, false otherwise.
-         */
-        bool has_rotten_away( item &itm, const tripoint &pnt ) const;
         /**
          * Go through the list of items, update their rotten status and remove items
          * that have rotten away completely.