From 63ce81570ce2f6ed4be53ca73bd0fbf8c358088b Mon Sep 17 00:00:00 2001
From: Peter Nelson <peter1138@openttd.org>
Date: Thu, 18 Apr 2024 00:04:47 +0100
Subject: [PATCH] Remove: Custom opendir implementation for Windows no longer
 needed.

std::filesystem::directory_iterator is now used instead.
---
 src/fileio_func.h        |  34 ------------
 src/os/windows/win32.cpp | 112 ---------------------------------------
 2 files changed, 146 deletions(-)

diff --git a/src/fileio_func.h b/src/fileio_func.h
index 9e85f1f8c0..eaa6f76164 100644
--- a/src/fileio_func.h
+++ b/src/fileio_func.h
@@ -81,40 +81,6 @@ public:
 
 DECLARE_ENUM_AS_BIT_SET(TarScanner::Mode)
 
-/* Implementation of opendir/readdir/closedir for Windows */
-#if defined(_WIN32)
-struct DIR;
-
-struct dirent { // XXX - only d_name implemented
-	wchar_t *d_name; // name of found file
-	/* little hack which will point to parent DIR struct which will
-	 * save us a call to GetFileAttributes if we want information
-	 * about the file (for example in function fio_bla) */
-	DIR *dir;
-};
-
-DIR *opendir(const wchar_t *path);
-struct dirent *readdir(DIR *d);
-int closedir(DIR *d);
-#else
-/* Use system-supplied opendir/readdir/closedir functions */
-# include <sys/types.h>
-# include <dirent.h>
-#endif /* defined(_WIN32) */
-
-/**
- * A wrapper around opendir() which will convert the string from
- * OPENTTD encoding to that of the filesystem. For all purposes this
- * function behaves the same as the original opendir function
- * @param path string to open directory of
- * @return DIR pointer
- */
-inline DIR *ttd_opendir(const char *path)
-{
-	return opendir(OTTD2FS(path).c_str());
-}
-
-
 /** Auto-close a file upon scope exit. */
 class FileCloser {
 	FILE *f;
diff --git a/src/os/windows/win32.cpp b/src/os/windows/win32.cpp
index b956027d52..c011e830f6 100644
--- a/src/os/windows/win32.cpp
+++ b/src/os/windows/win32.cpp
@@ -58,118 +58,6 @@ void OSOpenBrowser(const std::string &url)
 	ShellExecute(GetActiveWindow(), L"open", OTTD2FS(url).c_str(), nullptr, nullptr, SW_SHOWNORMAL);
 }
 
-/* Code below for windows version of opendir/readdir/closedir copied and
- * modified from Jan Wassenberg's GPL implementation posted over at
- * http://www.gamedev.net/community/forums/topic.asp?topic_id=364584&whichpage=1&#2398903 */
-
-struct DIR {
-	HANDLE hFind;
-	/* the dirent returned by readdir.
-	 * note: having only one global instance is not possible because
-	 * multiple independent opendir/readdir sequences must be supported. */
-	dirent ent;
-	WIN32_FIND_DATA fd;
-	/* since opendir calls FindFirstFile, we need a means of telling the
-	 * first call to readdir that we already have a file.
-	 * that's the case iff this is true */
-	bool at_first_entry;
-};
-
-/* suballocator - satisfies most requests with a reusable static instance.
- * this avoids hundreds of alloc/free which would fragment the heap.
- * To guarantee concurrency, we fall back to malloc if the instance is
- * already in use (it's important to avoid surprises since this is such a
- * low-level routine). */
-static DIR _global_dir;
-static LONG _global_dir_is_in_use = false;
-
-static inline DIR *dir_calloc()
-{
-	DIR *d;
-
-	if (InterlockedExchange(&_global_dir_is_in_use, true) == (LONG)true) {
-		d = CallocT<DIR>(1);
-	} else {
-		d = &_global_dir;
-		memset(d, 0, sizeof(*d));
-	}
-	return d;
-}
-
-static inline void dir_free(DIR *d)
-{
-	if (d == &_global_dir) {
-		_global_dir_is_in_use = (LONG)false;
-	} else {
-		free(d);
-	}
-}
-
-DIR *opendir(const wchar_t *path)
-{
-	DIR *d;
-	UINT sem = SetErrorMode(SEM_FAILCRITICALERRORS); // disable 'no-disk' message box
-	DWORD fa = GetFileAttributes(path);
-
-	if ((fa != INVALID_FILE_ATTRIBUTES) && (fa & FILE_ATTRIBUTE_DIRECTORY)) {
-		d = dir_calloc();
-		if (d != nullptr) {
-			std::wstring search_path = path;
-			bool slash = path[wcslen(path) - 1] == '\\';
-
-			/* build search path for FindFirstFile, try not to append additional slashes
-			 * as it throws Win9x off its groove for root directories */
-			if (!slash) search_path += L"\\";
-			search_path += L"*";
-			d->hFind = FindFirstFile(search_path.c_str(), &d->fd);
-
-			if (d->hFind != INVALID_HANDLE_VALUE ||
-					GetLastError() == ERROR_NO_MORE_FILES) { // the directory is empty
-				d->ent.dir = d;
-				d->at_first_entry = true;
-			} else {
-				dir_free(d);
-				d = nullptr;
-			}
-		} else {
-			errno = ENOMEM;
-		}
-	} else {
-		/* path not found or not a directory */
-		d = nullptr;
-		errno = ENOENT;
-	}
-
-	SetErrorMode(sem); // restore previous setting
-	return d;
-}
-
-struct dirent *readdir(DIR *d)
-{
-	DWORD prev_err = GetLastError(); // avoid polluting last error
-
-	if (d->at_first_entry) {
-		/* the directory was empty when opened */
-		if (d->hFind == INVALID_HANDLE_VALUE) return nullptr;
-		d->at_first_entry = false;
-	} else if (!FindNextFile(d->hFind, &d->fd)) { // determine cause and bail
-		if (GetLastError() == ERROR_NO_MORE_FILES) SetLastError(prev_err);
-		return nullptr;
-	}
-
-	/* This entry has passed all checks; return information about it.
-	 * (note: d_name is a pointer; see struct dirent definition) */
-	d->ent.d_name = d->fd.cFileName;
-	return &d->ent;
-}
-
-int closedir(DIR *d)
-{
-	FindClose(d->hFind);
-	dir_free(d);
-	return 0;
-}
-
 bool FiosIsRoot(const std::string &file)
 {
 	return file.size() == 3; // C:\...