Changeset - r14077:8447889ed7f9
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master
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rubidium - 14 years ago 2009-12-25 23:14:12
rubidium@openttd.org
(svn r18634) -Revert (r16808): the fix doesn't work in all cases
-Fix [FS#3421] (r16838): crash when invalid pointers are left due to saveload failing at e.g. decompressing the savegame
1 file changed with 50 insertions and 29 deletions:
0 comments (0 inline, 0 general)
src/saveload/saveload.cpp
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@@ -64,6 +64,7 @@ enum SaveLoadAction {
 
	SLA_LOAD, ///< loading
 
	SLA_SAVE, ///< saving
 
	SLA_PTRS, ///< fixing pointers
 
	SLA_NULL, ///< null all pointers (on loading error)
 
};
 

	
 
enum NeedLength {
 
@@ -106,6 +107,32 @@ struct SaveLoadParams {
 

	
 
static SaveLoadParams _sl;
 

	
 
/** Null all pointers (convert index -> NULL) */
 
static void SlNullPointers()
 
{
 
	const ChunkHandler *ch;
 
	const ChunkHandler * const *chsc;
 

	
 
	_sl.action = SLA_NULL;
 

	
 
	DEBUG(sl, 1, "Nulling pointers");
 

	
 
	for (chsc = _sl.chs; (ch = *chsc++) != NULL;) {
 
		while (true) {
 
			if (ch->ptrs_proc != NULL) {
 
				DEBUG(sl, 2, "Nulling pointers for %c%c%c%c", ch->id >> 24, ch->id >> 16, ch->id >> 8, ch->id);
 
				ch->ptrs_proc();
 
			}
 
			if (ch->flags & CH_LAST) break;
 
			ch++;
 
		}
 
	}
 

	
 
	DEBUG(sl, 1, "All pointers nulled");
 

	
 
	assert(_sl.action == SLA_NULL);
 
}
 

	
 
/** Error handler, calls longjmp to simulate an exception.
 
 * @todo this was used to have a central place to handle errors, but it is
 
 * pretty ugly, and seriously interferes with any multithreaded approaches */
 
@@ -114,6 +141,11 @@ static void NORETURN SlError(StringID st
 
	_sl.error_str = string;
 
	free(_sl.extra_msg);
 
	_sl.extra_msg = (extra_msg == NULL) ? NULL : strdup(extra_msg);
 
	/* We have to NULL all pointers here; we might be in a state where
 
	 * the pointers are actually filled with indices, which means that
 
	 * when we access them during cleaning the pool dereferences of
 
	 * those indices will be made with segmentation faults as result. */
 
	SlNullPointers();
 
	throw std::exception();
 
}
 

	
 
@@ -570,6 +602,7 @@ static void SlSaveLoadConv(void *ptr, Va
 
			break;
 
		}
 
		case SLA_PTRS: break;
 
		case SLA_NULL: break;
 
		default: NOT_REACHED();
 
	}
 
}
 
@@ -678,6 +711,7 @@ static void SlString(void *ptr, size_t l
 
			break;
 
		}
 
		case SLA_PTRS: break;
 
		case SLA_NULL: break;
 
		default: NOT_REACHED();
 
	}
 
}
 
@@ -700,7 +734,7 @@ static inline size_t SlCalcArrayLen(size
 
 */
 
void SlArray(void *array, size_t length, VarType conv)
 
{
 
	if (_sl.action == SLA_PTRS) return;
 
	if (_sl.action == SLA_PTRS || _sl.action == SLA_NULL) return;
 

	
 
	/* Automatically calculate the length? */
 
	if (_sl.need_length != NL_NONE) {
 
@@ -811,6 +845,9 @@ static void SlList(void *list, SLRefType
 
			}
 
			break;
 
		}
 
		case SLA_NULL:
 
			l->clear();
 
			break;
 
		default: NOT_REACHED();
 
	}
 
}
 
@@ -912,6 +949,9 @@ bool SlObjectMember(void *ptr, const Sav
 
						case SLA_PTRS:
 
							*(void **)ptr = IntToReference(*(size_t *)ptr, (SLRefType)conv);
 
							break;
 
						case SLA_NULL:
 
							*(void **)ptr = NULL;
 
							break;
 
						default: NOT_REACHED();
 
					}
 
					break;
 
@@ -932,6 +972,7 @@ bool SlObjectMember(void *ptr, const Sav
 
				case SLA_SAVE: SlWriteByte(sld->version_to); break;
 
				case SLA_LOAD: *(byte *)ptr = sld->version_from; break;
 
				case SLA_PTRS: break;
 
				case SLA_NULL: break;
 
				default: NOT_REACHED();
 
			}
 
			break;
 
@@ -1146,8 +1187,6 @@ static void SlLoadChunks()
 
	}
 
}
 

	
 
static const char *_sl_ptrs_error; ///< error message if there was an error during fixing pointers, NULL otherwise
 

	
 
/** Fix all pointers (convert index -> pointer) */
 
static void SlFixPointers()
 
{
 
@@ -1155,7 +1194,6 @@ static void SlFixPointers()
 
	const ChunkHandler * const *chsc;
 

	
 
	_sl.action = SLA_PTRS;
 
	_sl_ptrs_error = NULL;
 

	
 
	DEBUG(sl, 1, "Fixing pointers");
 

	
 
@@ -1171,9 +1209,6 @@ static void SlFixPointers()
 
		}
 
	}
 

	
 
	/* We need to fix all possible pointers even if there were invalid ones. This way pool cleaning will work fine. */
 
	if (_sl_ptrs_error != NULL) SlError(STR_GAME_SAVELOAD_ERROR_BROKEN_SAVEGAME, _sl_ptrs_error);
 

	
 
	DEBUG(sl, 1, "All pointers fixed");
 

	
 
	assert(_sl.action == SLA_PTRS);
 
@@ -1537,55 +1572,41 @@ static void *IntToReference(size_t index
 
	switch (rt) {
 
		case REF_ORDERLIST:
 
			if (OrderList::IsValidID(index)) return OrderList::Get(index);
 
			_sl_ptrs_error = "Referencing invalid OrderList";
 
			break;
 
			SlError(STR_GAME_SAVELOAD_ERROR_BROKEN_SAVEGAME, "Referencing invalid OrderList");
 

	
 
		case REF_ORDER:
 
			if (Order::IsValidID(index)) return Order::Get(index);
 
			/* in old versions, invalid order was used to mark end of order list */
 
			if (CheckSavegameVersionOldStyle(5, 2)) return NULL;
 
			_sl_ptrs_error = "Referencing invalid Order";
 
			break;
 
			SlError(STR_GAME_SAVELOAD_ERROR_BROKEN_SAVEGAME, "Referencing invalid Order");
 

	
 
		case REF_VEHICLE_OLD:
 
		case REF_VEHICLE:
 
			if (Vehicle::IsValidID(index)) return Vehicle::Get(index);
 
			_sl_ptrs_error = "Referencing invalid Vehicle";
 
			break;
 
			SlError(STR_GAME_SAVELOAD_ERROR_BROKEN_SAVEGAME, "Referencing invalid Vehicle");
 

	
 
		case REF_STATION:
 
			if (Station::IsValidID(index)) return Station::Get(index);
 
			_sl_ptrs_error = "Referencing invalid Station";
 
			break;
 
			SlError(STR_GAME_SAVELOAD_ERROR_BROKEN_SAVEGAME, "Referencing invalid Station");
 

	
 
		case REF_TOWN:
 
			if (Town::IsValidID(index)) return Town::Get(index);
 
			_sl_ptrs_error = "Referencing invalid Town";
 
			break;
 
			SlError(STR_GAME_SAVELOAD_ERROR_BROKEN_SAVEGAME, "Referencing invalid Town");
 

	
 
		case REF_ROADSTOPS:
 
			if (RoadStop::IsValidID(index)) return RoadStop::Get(index);
 
			_sl_ptrs_error = "Referencing invalid RoadStop";
 
			break;
 
			SlError(STR_GAME_SAVELOAD_ERROR_BROKEN_SAVEGAME, "Referencing invalid RoadStop");
 

	
 
		case REF_ENGINE_RENEWS:
 
			if (EngineRenew::IsValidID(index)) return EngineRenew::Get(index);
 
			_sl_ptrs_error = "Referencing invalid EngineRenew";
 
			break;
 
			SlError(STR_GAME_SAVELOAD_ERROR_BROKEN_SAVEGAME, "Referencing invalid EngineRenew");
 

	
 
		case REF_CARGO_PACKET:
 
			if (CargoPacket::IsValidID(index)) return CargoPacket::Get(index);
 
			_sl_ptrs_error = "Referencing invalid CargoPacket";
 
			break;
 
			SlError(STR_GAME_SAVELOAD_ERROR_BROKEN_SAVEGAME, "Referencing invalid CargoPacket");
 

	
 
		default: NOT_REACHED();
 
	}
 

	
 
	/* Print a debug message about each invalid reference */
 
	DEBUG(sl, 1, "%s (index = " PRINTF_SIZE ")", _sl_ptrs_error, index);
 

	
 
	/* Return NULL for broken savegames */
 
	return NULL;
 
}
 

	
 
/** The format for a reader/writer type of a savegame */
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