Need ctype.h for isdigit()

src/xpdev/sockwrap.c

@@ -35,6 +35,7 @@
  * Note: If this box doesn't appear square, then you need to fix your tabs.	*
  ****************************************************************************/
 
+#include <ctype.h>		/* isdigit */
 #include <stdlib.h>		/* alloca/free on FreeBSD */
 #include <string.h>		/* bzero (for FD_ZERO) on FreeBSD */
 #include <errno.h>		/* ENOMEM */