fix(zone): read a zone's paths as the chunk the client reads

The client reads a zone file's paths as a chunk of its own
(LuzFile::ReadLUZFile copies the u32-sized chunk, ReadLUZPaths reads
it, 1.10.64) and drops every path when it refuses any of it:
- a chunk version of 2 or more, or 10000 paths or more (ReadLUZPaths);
- a path of version 19 or more, 10000 waypoints or more, or a
  waypoint with more than 99 name/value pairs (LevelPath::FromBuffer).

The reader read the paths straight from the file, trusting the chunk to
be well formed. It now reads the chunk by its size, reads the paths
from it with the client's limits, and when one is refused the zone has
no paths (logged), while the rest of the zone file still reads.

Every zone file on disk reads the same paths as before.

The unit tests' sample zones now give the path chunk its real length.

Check in game: moving platforms, NPC patrols and spawners work as
before on every world.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

dCommon/ZoneFile.cpp

@@ -4,6 +4,8 @@
 #include <cctype>
 #include <cstdint>
 #include <istream>
+#include <sstream>
+#include <stdexcept>
 #include <string>
 
 #include "BinaryIO.h"
@@ -60,15 +62,38 @@ void ZoneFile::Read(std::istream& file) {
 	}
 
 	if (fileFormatVersion >= FileFormatVersion::EarlyAlpha) {
+		// The paths are a chunk of their own (LuzFile::ReadLUZFile copies it, ReadLUZPaths reads it)
 		BinaryIO::BinaryRead(file, pathDataLength);
-		BinaryIO::BinaryRead(file, pathChunkVersion); // always should be 1
+		std::string chunk(pathDataLength, '\0');
+		file.read(chunk.data(), static_cast<std::streamsize>(chunk.size()));
+		if (!file) throw std::runtime_error("Failed to read from istream.");
+		std::istringstream pathChunk(chunk);
+		if (!ReadPaths(pathChunk)) {
+			LOG("The zone file's paths are not ones the client reads; the zone has no paths, as in the client");
+			paths.clear();
+		}
+	}
+}
+
+bool ZoneFile::ReadPaths(std::istream& file) {
+	// ReadLUZPaths: a chunk version from 2 on, 10000 paths or more, or any path LevelPath::FromBuffer refuses (it reads
+	// no further than the chunk's end here) leaves the zone with no paths
+	try {
+		BinaryIO::BinaryRead(file, pathChunkVersion);
+		if (pathChunkVersion >= 2) return false;
 
 		uint32_t pathCount;
 		BinaryIO::BinaryRead(file, pathCount);
+		if (pathCount >= 10000) return false;
 
 		paths.reserve(pathCount);
-		for (uint32_t i = 0; i < pathCount; ++i) ReadPath(file);
+		for (uint32_t i = 0; i < pathCount; ++i) {
+			if (!ReadPath(file)) return false;
+		}
+	} catch (const std::runtime_error&) {
+		return false;
 	}
+	return true;
 }
 
 void ZoneFile::ReadScene(std::istream& file, uint32_t index) {
@@ -187,9 +212,10 @@ SceneTransitionInfo ZoneFile::ReadSceneTransitionInfo(std::istream& file) {
 	return info;
 }
 
-void ZoneFile::ReadLdfConfig(std::istream& file, PathType pathType, PathWaypoint& waypoint) {
+bool ZoneFile::ReadLdfConfig(std::istream& file, PathType pathType, PathWaypoint& waypoint) {
 	uint32_t count;
 	BinaryIO::BinaryRead(file, count);
+	if (count > 99) return false; // LevelPath::FromBuffer refuses the path
 	for (uint32_t i = 0; i < count; ++i) {
 		std::string parameter;
 		BinaryIO::ReadString<uint8_t>(file, parameter, BinaryIO::ReadType::WideString);
@@ -211,12 +237,14 @@ void ZoneFile::ReadLdfConfig(std::istream& file, PathType pathType, PathWaypoint
 			waypoint.config.ParseInsert(parameter + "=" + value);
 		}
 	}
+	return true;
 }
 
-void ZoneFile::ReadPath(std::istream& file) {
+bool ZoneFile::ReadPath(std::istream& file) {
 	Path path = Path();
 
 	BinaryIO::BinaryRead(file, path.pathVersion);
+	if (path.pathVersion >= 19) return false; // LevelPath::FromBuffer refuses it
 
 	BinaryIO::ReadString<uint8_t>(file, path.pathName, BinaryIO::ReadType::WideString);
 
@@ -277,6 +305,7 @@ void ZoneFile::ReadPath(std::istream& file) {
 	// Read waypoints
 
 	BinaryIO::BinaryRead(file, path.waypointCount);
+	if (path.waypointCount >= 10000) return false; // LevelPath::FromBuffer refuses it
 	path.pathWaypoints.reserve(path.waypointCount);
 	for (uint32_t i = 0; i < path.waypointCount; ++i) {
 		PathWaypoint waypoint = PathWaypoint();
@@ -294,7 +323,7 @@ void ZoneFile::ReadPath(std::istream& file) {
 			BinaryIO::BinaryRead(file, waypoint.movingPlatform.lockPlayer);
 			BinaryIO::BinaryRead(file, waypoint.speed);
 			BinaryIO::BinaryRead(file, waypoint.movingPlatform.wait);
-			ReadLdfConfig(file, path.pathType, waypoint);
+			if (!ReadLdfConfig(file, path.pathType, waypoint)) return false;
 			path.pathWaypoints.push_back(waypoint);
 			continue;
 		}
@@ -332,10 +361,11 @@ void ZoneFile::ReadPath(std::istream& file) {
 
 		// object LDF configs
 		if (path.pathType == PathType::Movement || path.pathType == PathType::Spawner || path.pathType == PathType::Rail) {
-			ReadLdfConfig(file, path.pathType, waypoint);
+			if (!ReadLdfConfig(file, path.pathType, waypoint)) return false;
 		}
 
 		path.pathWaypoints.push_back(waypoint);
 	}
 	paths.push_back(path);
+	return true;
 }

dCommon/ZoneFile.h

@@ -260,7 +260,8 @@ private:
 	void ReadZoneBoundaries(std::istream& file);
 	void ReadSceneTransition(std::istream& file);
 	SceneTransitionInfo ReadSceneTransitionInfo(std::istream& file);
-	void ReadPath(std::istream& file);
+	bool ReadPaths(std::istream& file);
+	bool ReadPath(std::istream& file);
 	// A waypoint's name/value pairs: waypoint commands on movement and rail paths, LDF config on the others
-	static void ReadLdfConfig(std::istream& file, PathType pathType, PathWaypoint& waypoint);
+	static bool ReadLdfConfig(std::istream& file, PathType pathType, PathWaypoint& waypoint);
 };