Adding upstream version 15.4.upstream/15.4upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 68 insertions, 0 deletions

diff --git a/src/port/win32common.c b/src/port/win32common.c
new file mode 100644
index 0000000..2fd78f7
--- /dev/null
+++ b/src/port/win32common.c
@@ -0,0 +1,68 @@
+/*-------------------------------------------------------------------------
+ *
+ * win32common.c
+ *	  Common routines shared among the win32*.c ports.
+ *
+ * Portions Copyright (c) 1996-2023, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/port/win32common.c
+ *
+ *-------------------------------------------------------------------------
+ */
+
+#ifdef FRONTEND
+#include "postgres_fe.h"
+#else
+#include "postgres.h"
+#endif
+
+#ifdef WIN32
+
+/*
+ * pgwin32_get_file_type
+ *
+ * Convenience wrapper for GetFileType() with specific error handling for all the
+ * port implementations.  Returns the file type associated with a HANDLE.
+ *
+ * On error, sets errno with FILE_TYPE_UNKNOWN as file type.
+ */
+DWORD
+pgwin32_get_file_type(HANDLE hFile)
+{
+	DWORD		fileType = FILE_TYPE_UNKNOWN;
+	DWORD		lastError;
+
+	errno = 0;
+
+	/*
+	 * When stdin, stdout, and stderr aren't associated with a stream the
+	 * special value -2 is returned:
+	 * https://learn.microsoft.com/en-us/cpp/c-runtime-library/reference/get-osfhandle
+	 */
+	if (hFile == INVALID_HANDLE_VALUE || hFile == (HANDLE) -2)
+	{
+		errno = EINVAL;
+		return FILE_TYPE_UNKNOWN;
+	}
+
+	fileType = GetFileType(hFile);
+	lastError = GetLastError();
+
+	/*
+	 * Invoke GetLastError in order to distinguish between a "valid" return of
+	 * FILE_TYPE_UNKNOWN and its return due to a calling error.  In case of
+	 * success, GetLastError() returns NO_ERROR.
+	 */
+	if (fileType == FILE_TYPE_UNKNOWN && lastError != NO_ERROR)
+	{
+		_dosmaperr(lastError);
+		return FILE_TYPE_UNKNOWN;
+	}
+
+	return fileType;
+}
+
+#endif							/* WIN32 */