+ /* DEC OSF 4.0 fpathconf returns 255, but xemacs hangs on long shell
+ input lines if we return 253. 252 is OK!. So let's leave a bit
+ of slack for the newline that xemacs will insert, and for those
+ inevitable vendor off-by-one-or-two-or-three bugs. */
+#define MAX_CANON_SLACK 10
+#define SAFE_MAX_CANON (127 - MAX_CANON_SLACK)