From bd742fbe20493f720ae6af00525fd3a8ee829802 Mon Sep 17 00:00:00 2001
From: Joel Rosdahl <joel@rosdahl.net>
Date: Sun, 21 Jun 2020 21:29:04 +0200
Subject: [PATCH] Remove win32 GetFileNameFromHandle compatibility function
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The replacement function seems to be buggy, triggering failures in
x_realpath at least when the unit tests are run in Wine. The real
GetFinalPathNameByHandle function is allegedly supported in Windows
Vista and newer, so let’s just use it.
---
 configure.ac |  1 -
 src/util.c   | 92 ++++------------------------------------------------
 2 files changed, 6 insertions(+), 87 deletions(-)

diff --git a/configure.ac b/configure.ac
index 01098842e..8278592c8 100644
--- a/configure.ac
+++ b/configure.ac
@@ -177,7 +177,6 @@ fi
 dnl Linking on Windows needs ws2_32
 if test x${windows_os} = xyes; then
     LIBS="$LIBS -lws2_32"
-    AC_CHECK_FUNCS(GetFinalPathNameByHandleW,[],[LIBS="$LIBS -lpsapi"])
 fi
 
 AC_C_BIGENDIAN
diff --git a/src/util.c b/src/util.c
index 4aa99f424..9f014bdc2 100644
--- a/src/util.c
+++ b/src/util.c
@@ -1083,87 +1083,6 @@ parse_size_with_suffix(const char *str, uint64_t *size)
 	return true;
 }
 
-
-#if !defined(HAVE_REALPATH) && \
-  defined(_WIN32) && \
-  !defined(HAVE_GETFINALPATHNAMEBYHANDLEW)
-static BOOL GetFileNameFromHandle(HANDLE file_handle, TCHAR *filename,
-                                  WORD cch_filename)
-{
-	BOOL success = FALSE;
-
-	// Get the file size.
-	DWORD file_size_hi = 0;
-	DWORD file_size_lo = GetFileSize(file_handle, &file_size_hi);
-	if (file_size_lo == 0 && file_size_hi == 0) {
-		// Cannot map a file with a length of zero.
-		return FALSE;
-	}
-
-	// Create a file mapping object.
-	HANDLE file_map =
-		CreateFileMapping(file_handle, NULL, PAGE_READONLY, 0, 1, NULL);
-	if (!file_map) {
-		return FALSE;
-	}
-
-	// Create a file mapping to get the file name.
-	void *mem = MapViewOfFile(file_map, FILE_MAP_READ, 0, 0, 1);
-	if (mem) {
-		if (GetMappedFileName(GetCurrentProcess(),
-		                      mem,
-		                      filename,
-		                      cch_filename)) {
-			// Translate path with device name to drive letters.
-			TCHAR temp[512];
-			temp[0] = '\0';
-
-			if (GetLogicalDriveStrings(512-1, temp)) {
-				TCHAR name[MAX_PATH];
-				TCHAR drive[3] = TEXT(" :");
-				BOOL found = FALSE;
-				TCHAR *p = temp;
-
-				do {
-					// Copy the drive letter to the template string.
-					*drive = *p;
-
-					// Look up each device name.
-					if (QueryDosDevice(drive, name, MAX_PATH)) {
-						size_t name_len = _tcslen(name);
-						if (name_len < MAX_PATH) {
-							found = _tcsnicmp(filename, name, name_len) == 0
-							        && *(filename + name_len) == _T('\\');
-							if (found) {
-								// Reconstruct filename using temp_file and replace device path
-								// with DOS path.
-								TCHAR temp_file[MAX_PATH];
-								_sntprintf(temp_file,
-								           MAX_PATH - 1,
-								           TEXT("%s%s"),
-								           drive,
-								           filename+name_len);
-								strcpy(filename, temp_file);
-							}
-						}
-					}
-
-					// Go to the next NULL character.
-					while (*p++) {
-						// Do nothing.
-					}
-				} while (!found && *p); // End of string.
-			}
-		}
-		success = TRUE;
-		UnmapViewOfFile(mem);
-	}
-
-	CloseHandle(file_map);
-	return success;
-}
-#endif
-
 // A sane realpath() function, trying to cope with stupid path limits and a
 // broken API. Caller frees.
 char *
@@ -1183,12 +1102,13 @@ x_realpath(const char *path)
 		path, GENERIC_READ, FILE_SHARE_READ, NULL, OPEN_EXISTING,
 		FILE_ATTRIBUTE_NORMAL, NULL);
 	if (INVALID_HANDLE_VALUE != path_handle) {
-#ifdef HAVE_GETFINALPATHNAMEBYHANDLEW
-		GetFinalPathNameByHandle(path_handle, ret, maxlen, FILE_NAME_NORMALIZED);
-#else
-		GetFileNameFromHandle(path_handle, ret, maxlen);
-#endif
+		bool ok = GetFinalPathNameByHandle(
+			path_handle, ret, maxlen, FILE_NAME_NORMALIZED) != 0;
 		CloseHandle(path_handle);
+		if (!ok) {
+			free(ret);
+			return x_strdup(path);
+		}
 		p = ret + 4; // Strip \\?\ from the file name.
 	} else {
 		snprintf(ret, maxlen, "%s", path);
-- 
2.47.2