Fix support for O_APPEND on files opened with openfile() on Windows.

1 files changed, 12 insertions, 0 deletions

diff --git a/lib/win32/emu.cpp b/lib/win32/emu.cpp
index e31d8a3c..84246c67 100644
--- a/lib/win32/emu.cpp
+++ b/lib/win32/emu.cpp
@@ -693,6 +693,18 @@ HANDLE openfile(const char *pFileName, int flags, int mode)
 		return INVALID_HANDLE_VALUE;
 	}
 
+	if (flags & O_APPEND)
+	{
+		if (SetFilePointer(hdir, 0, NULL, FILE_END) ==
+			INVALID_SET_FILE_POINTER)
+		{
+			winerrno = GetLastError();
+			errno = EINVAL;
+			CloseHandle(hdir);
+			return INVALID_HANDLE_VALUE;
+		}
+	}
+
 	winerrno = NO_ERROR;
 	return hdir;
 }