Core: Actually take item from pool when plandoing from_pool

Fill.py

@@ -921,15 +921,32 @@ def failed(warning: str, force: typing.Union[bool, str]) -> None:
             multiworld.random.shuffle(items)
             count = 0
             err: typing.List[str] = []
-            successful_pairs: typing.List[typing.Tuple[Item, Location]] = []
+            successful_pairs: typing.List[typing.Tuple[int, Item, Location]] = []
+            claimed_indices: typing.Set[typing.Optional[int]] = set()
             for item_name in items:
-                item = multiworld.worlds[player].create_item(item_name)
+                index_to_delete: typing.Optional[int] = None
+                if from_pool:
+                    try:
+                        # If from_pool, try to find an existing item with this name & player in the itempool and use it
+                        index_to_delete, item = next(
+                            (i, item) for i, item in enumerate(multiworld.itempool)
+                            if item.player == player and item.name == item_name and i not in claimed_indices
+                        )
+                    except StopIteration:
+                        warn(
+                        f"Could not remove {item_name} from pool for {multiworld.player_name[player]} as it's already missing from it.",
+                        placement['force'])
+                        item = multiworld.worlds[player].create_item(item_name)
+                else:
+                    item = multiworld.worlds[player].create_item(item_name)
+
                 for location in reversed(candidates):
                     if (location.address is None) == (item.code is None):  # either both None or both not None
                         if not location.item:
                             if location.item_rule(item):
                                 if location.can_fill(multiworld.state, item, False):
-                                    successful_pairs.append((item, location))
+                                    successful_pairs.append((index_to_delete, item, location))
+                                    claimed_indices.add(index_to_delete)
                                     candidates.remove(location)
                                     count = count + 1
                                     break
@@ -941,25 +958,25 @@ def failed(warning: str, force: typing.Union[bool, str]) -> None:
                             err.append(f"Cannot place {item_name} into already filled location {location}.")
                     else:
                         err.append(f"Mismatch between {item_name} and {location}, only one is an event.")
+
                 if count == maxcount:
                     break
             if count < placement['count']['min']:
                 m = placement['count']['min']
                 failed(
                     f"Plando block failed to place {m - count} of {m} item(s) for {multiworld.player_name[player]}, error(s): {' '.join(err)}",
                     placement['force'])
-            for (item, location) in successful_pairs:
+
+            # Sort indices in reverse so we can remove them one by one
+            successful_pairs = sorted(successful_pairs, key=lambda successful_pair: successful_pair[0] or 0, reverse=True)
+
+            for (index, item, location) in successful_pairs:
                 multiworld.push_item(location, item, collect=False)
                 location.event = True  # flag location to be checked during fill
                 location.locked = True
                 logging.debug(f"Plando placed {item} at {location}")
-                if from_pool:
-                    try:
-                        multiworld.itempool.remove(item)
-                    except ValueError:
-                        warn(
-                            f"Could not remove {item} from pool for {multiworld.player_name[player]} as it's already missing from it.",
-                            placement['force'])
+                if index is not None:  # If this item is from_pool and was found in the pool, remove it.
+                    multiworld.itempool.pop(index)
 
         except Exception as e:
             raise Exception(