--- /dev/null
+#include "ptx4.h"
+
+/* Gelling Kevan (gellingk.eurostar@ems.rail.co.uk)
+ says that PTX 4.2.3 needs this version. */
+#undef SETUP_SLAVE_PTY
+#define SETUP_SLAVE_PTY \
+ if (ioctl (xforkin, I_PUSH, "ptem") == -1) \
+ fatal ("ioctl I_PUSH ptem", errno); \
+ if (ioctl (xforkin, I_PUSH, "ldterm") == -1) \
+ fatal ("ioctl I_PUSH ldterm", errno);
+
+/* Gelling Kevan (gellingk.eurostar@ems.rail.co.uk)
+ says that gmalloc.c needs _POSIX_SOURCE.
+ This defines _POSIX_SOURCE only for gmalloc.c. */
+#ifdef _MALLOC_INTERNAL
+#define _POSIX_SOURCE
+#endif