Fix:    NH004

Problem:
	msummon() assumes that ndemon() et. al. return 0 on failure,
	whereas these have been changed (since 3.2.3) to return NON_PM,
	presumably because 0 offically refers to giant ants. This causes
	the game to panic with an error of
	          monsndx - could not index monster (-1)
	if the RNG is feeling particuarly unhelpful.

Compatible with:
	NetHack 3.3.0
	SlashEM 0.0.6E1F2

Author: J. Ali Harlow, ali@avrc.city.ac.uk

Date:   1 Jun 2000

diff -Nacrd ../nethack-3.3.0/src/minion.c ./src/minion.c
*** ../nethack-3.3.0/src/minion.c	Tue Apr 25 16:51:13 2000
--- ./src/minion.c	Thu Jun  1 21:23:17 2000
***************
*** 10,16 ****
  msummon(ptr)		/* ptr summons a monster */
  register struct permonst *ptr;
  {
! 	register int dtype = 0, cnt = 0;
  	aligntyp atyp = sgn(ptr->maligntyp);
  
  	if (is_dprince(ptr) || (ptr == &mons[PM_WIZARD_OF_YENDOR])) {
--- 10,16 ----
  msummon(ptr)		/* ptr summons a monster */
  register struct permonst *ptr;
  {
! 	register int dtype = NON_PM, cnt = 0;
  	aligntyp atyp = sgn(ptr->maligntyp);
  
  	if (is_dprince(ptr) || (ptr == &mons[PM_WIZARD_OF_YENDOR])) {
***************
*** 31,37 ****
  	    cnt = (!rn2(4) && !is_lord(&mons[dtype])) ? 2 : 1;
  	}
  
! 	if (!dtype) return;
  
  	/* sanity checks */
  	if (cnt > 1 && (mons[dtype].geno & G_UNIQ)) cnt = 1;
--- 31,37 ----
  	    cnt = (!rn2(4) && !is_lord(&mons[dtype])) ? 2 : 1;
  	}
  
! 	if (dtype < LOW_PM) return;
  
  	/* sanity checks */
  	if (cnt > 1 && (mons[dtype].geno & G_UNIQ)) cnt = 1;
***************
*** 41,47 ****
  	 */
  	if (mvitals[dtype].mvflags & G_GONE) {
  	    dtype = ndemon(atyp);
! 	    if (!dtype) return;
  	}
  
  	while (cnt > 0) {
--- 41,47 ----
  	 */
  	if (mvitals[dtype].mvflags & G_GONE) {
  	    dtype = ndemon(atyp);
! 	    if (dtype < LOW_PM) return;
  	}
  
  	while (cnt > 0) {