From 462146b644a7083efe817c86c3fc99c8c59fbc62 Mon Sep 17 00:00:00 2001
From: Lioncash <mathew1800@gmail.com>
Date: Sat, 7 Sep 2019 07:54:08 -0400
Subject: [PATCH 1/2] FileWriterWin32: Prevent implicit sign conversion within
 position()

---
 src/athena/FileWriterWin32.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/athena/FileWriterWin32.cpp b/src/athena/FileWriterWin32.cpp
index 9a6cd43..684927d 100644
--- a/src/athena/FileWriterWin32.cpp
+++ b/src/athena/FileWriterWin32.cpp
@@ -89,7 +89,7 @@ atUint64 FileWriter::position() const {
   LARGE_INTEGER li = {};
   LARGE_INTEGER res;
   SetFilePointerEx(m_fileHandle, li, &res, FILE_CURRENT);
-  return res.QuadPart;
+  return static_cast<atUint64>(res.QuadPart);
 }
 
 atUint64 FileWriter::length() const { return utility::fileSize(m_filename); }

From 3b1348a26a2235d192ae185609aacd6e124bc660 Mon Sep 17 00:00:00 2001
From: Lioncash <mathew1800@gmail.com>
Date: Sat, 7 Sep 2019 07:55:23 -0400
Subject: [PATCH 2/2] FileWriterWin32: Handle large files within writeUBytes

Handles the case where a given size exceeds the maximum value that can
be contained within a DWORD.

Given a DWORD is 32-bit in size and an atUint64 is 64-bits in size, this
avoids errors on valid sizes, even if they're extremely unlikely to ever
occur.
---
 src/athena/FileWriterWin32.cpp | 33 ++++++++++++++++++++++++---------
 1 file changed, 24 insertions(+), 9 deletions(-)

diff --git a/src/athena/FileWriterWin32.cpp b/src/athena/FileWriterWin32.cpp
index 684927d..7e2d117 100644
--- a/src/athena/FileWriterWin32.cpp
+++ b/src/athena/FileWriterWin32.cpp
@@ -1,5 +1,10 @@
 #include "athena/FileWriter.hpp"
-#include "win32_largefilewrapper.h"
+
+#include <algorithm>
+#include <limits>
+
+#undef min
+#undef max
 
 namespace athena::io {
 FileWriter::FileWriter(std::string_view filename, bool overwrite, bool globalErr)
@@ -96,19 +101,29 @@ atUint64 FileWriter::length() const { return utility::fileSize(m_filename); }
 
 void FileWriter::writeUBytes(const atUint8* data, atUint64 len) {
   if (!isOpen()) {
-    if (m_globalErr)
+    if (m_globalErr) {
       atError(fmt("File not open for writing"));
+    }
     setError();
     return;
   }
 
-  DWORD ret = 0;
-  WriteFile(m_fileHandle, data, len, &ret, nullptr);
-  if (ret != len) {
-    if (m_globalErr)
-      atError(fmt("Unable to write to stream"));
-    setError();
-  }
+  atUint64 remaining = len;
+  do {
+    const auto toWrite = static_cast<DWORD>(std::min(remaining, atUint64{std::numeric_limits<DWORD>::max()}));
+    DWORD written = 0;
+
+    if (WriteFile(m_fileHandle, data, toWrite, &written, nullptr) == FALSE) {
+      if (m_globalErr) {
+        atError(fmt("Unable to write to file"));
+      }
+      setError();
+      return;
+    }
+
+    remaining -= written;
+    data += written;
+  } while (remaining != 0);
 }
 
 } // namespace athena::io