From d746282206486223da841605e5798b7eb1359752 Mon Sep 17 00:00:00 2001
From: Matthew Jimenez <matthew.jimenez@outlook.com>
Date: Sun, 17 Dec 2023 16:14:37 -0600
Subject: [PATCH] ULTIMA8: Read flex file metadata instead of seeking back to
 the table.

---
 engines/ultima/ultima8/filesys/flex_file.cpp  | 67 +++++++++++--------
 engines/ultima/ultima8/filesys/flex_file.h    | 15 +++--
 .../ultima/ultima8/filesys/u8_save_file.cpp   |  2 +-
 3 files changed, 50 insertions(+), 34 deletions(-)

diff --git a/engines/ultima/ultima8/filesys/flex_file.cpp b/engines/ultima/ultima8/filesys/flex_file.cpp
index 09d2ee62263..a57ff3acdec 100644
--- a/engines/ultima/ultima8/filesys/flex_file.cpp
+++ b/engines/ultima/ultima8/filesys/flex_file.cpp
@@ -31,25 +31,11 @@ static const int FLEX_TABLE_OFFSET = 0x80;
 static const int FLEX_HDR_SIZE = 0x52;
 static const char FLEX_HDR_PAD = 0x1A;
 
-FlexFile::FlexFile(Common::SeekableReadStream *rs) : _rs(rs), _count(0) {
+FlexFile::FlexFile(Common::SeekableReadStream *rs) : _rs(rs) {
 	_valid = isFlexFile(_rs);
 
-	if (_valid) {
-		_rs->seek(FLEX_HDR_SIZE + 2);
-		_count = _rs->readUint32LE();
-	}
-	if (_count > 4095) {
-		// In practice the largest flex in either Crusader or U8 games has
-		// 3074 entries, so this seems invalid.
-		warning("Flex invalid: improbable number of entries %d", _count);
-		_valid = false;
-		_count = 0;
-	}
-	if (rs->size() < FLEX_TABLE_OFFSET + 8 * _count) {
-		warning("Flex invalid: stream not long enough for offset table");
-		_valid = false;
-		_count = 0;
-	}
+	if (_valid)
+		_valid = readMetadata();
 }
 
 FlexFile::~FlexFile() {
@@ -76,9 +62,33 @@ bool FlexFile::isFlexFile(Common::SeekableReadStream *rs) {
 	return false;
 }
 
-uint32 FlexFile::getOffset(uint32 index) {
-	_rs->seek(FLEX_TABLE_OFFSET + 8 * index);
-	return _rs->readUint32LE();
+bool FlexFile::readMetadata() {
+	_rs->seek(FLEX_HDR_SIZE + 2);
+	uint32 count = _rs->readUint32LE();
+
+	if (count > 4095) {
+		// In practice the largest flex in either Crusader or U8 games has
+		// 3074 entries, so this seems invalid.
+		warning("Flex invalid: improbable number of entries %d", count);
+		return false;
+	}
+
+	if (_rs->size() < FLEX_TABLE_OFFSET + 8 * count) {
+		warning("Flex invalid: stream not long enough for offset table");
+		return false;
+	}
+
+	_entries.reserve(count);
+	_rs->seek(FLEX_TABLE_OFFSET);
+	for (unsigned int i = 0; i < count; ++i) {
+		FileEntry fe;
+		fe._offset = _rs->readUint32LE();
+		fe._size = _rs->readUint32LE();
+
+		_entries.push_back(fe);
+	}
+
+	return true;
 }
 
 Common::SeekableReadStream *FlexFile::getDataSource(uint32 index, bool is_text) {
@@ -92,31 +102,30 @@ Common::SeekableReadStream *FlexFile::getDataSource(uint32 index, bool is_text)
 }
 
 uint8 *FlexFile::getObject(uint32 index, uint32 *sizep) {
-	if (index >= _count)
+	if (index >= _entries.size())
 		return nullptr;
 
-	uint32 size = getSize(index);
+	uint32 size = _entries[index]._size;
 	if (size == 0)
 		return nullptr;
 
 	uint8 *object = new uint8[size];
-	uint32 offset = getOffset(index);
+	uint32 offset = _entries[index]._offset;
 
 	_rs->seek(offset);
 	_rs->read(object, size);
 
-	if (sizep) *sizep = size;
+	if (sizep)
+		*sizep = size;
 
 	return object;
 }
 
 uint32 FlexFile::getSize(uint32 index) const {
-	if (index >= _count) return 0;
+	if (index >= _entries.size())
+		return 0;
 
-	_rs->seek(FLEX_TABLE_OFFSET + 4 + 8 * index);
-	uint32 length = _rs->readUint32LE();
-
-	return length;
+	return _entries[index]._size;
 }
 
 } // End of namespace Ultima8
diff --git a/engines/ultima/ultima8/filesys/flex_file.h b/engines/ultima/ultima8/filesys/flex_file.h
index 884922b09ee..8e5282cb740 100644
--- a/engines/ultima/ultima8/filesys/flex_file.h
+++ b/engines/ultima/ultima8/filesys/flex_file.h
@@ -63,25 +63,32 @@ public:
 	//! In an indexed file this is (probably) the highest index plus one,
 	//! while in a named file it's (probably) the actual count
 	uint32 getCount() const {
-		return _count;
+		return _entries.size();
 	}
 
 	//! Get the highest index in the file
 	//! Guaranteed to be sufficiently large for a vector that needs to
 	//!  store the indexed entries of this file
 	uint32 getIndexCount() const {
-		return _count;
+		return _entries.size();
 	}
 
 	static bool isFlexFile(Common::SeekableReadStream *rs);
 
 protected:
 	Common::SeekableReadStream *_rs;
-	uint32 _count;
 	bool _valid;
 
+	struct FileEntry {
+		uint32 _offset;
+		uint32 _size;
+		FileEntry() : _offset(0), _size(0) {}
+	};
+
+	Common::Array<FileEntry> _entries;
+
 private:
-	uint32 getOffset(uint32 index);
+	bool readMetadata();
 };
 
 } // End of namespace Ultima8
diff --git a/engines/ultima/ultima8/filesys/u8_save_file.cpp b/engines/ultima/ultima8/filesys/u8_save_file.cpp
index 21980a9e9ed..cf7c8816e70 100644
--- a/engines/ultima/ultima8/filesys/u8_save_file.cpp
+++ b/engines/ultima/ultima8/filesys/u8_save_file.cpp
@@ -55,7 +55,7 @@ bool U8SaveFile::readMetadata() {
 	for (unsigned int i = 0; i < count; ++i) {
 		uint32 namelen = _rs->readUint32LE();
 		char *name = new char[namelen];
-		_rs->read(name, static_cast<int32>(namelen));
+		_rs->read(name, namelen);
 
 		FileEntry fe;
 		fe._size = _rs->readUint32LE();