bouncing zaps

As From a bug report, don't let bounces go past the edge of closed
doors.  His suggested patch included some redundancy, which I've removed.

doc/fixes34.1

@@ -319,6 +319,7 @@ various missing or inappropriate "killed by" death messages
 second attack for two-weapon combat will miss if first knocks target away
 jousting effect no longer occurs every time riding character hits with lance
 skeletons should be able to wear the armor they're created with
+bouncing zaps should not bounce around the edge of closed doors
 
 
 Platform- and/or Interface-Specific Fixes

src/zap.c

@@ -3441,10 +3441,12 @@ register int dx,dy;
 		dy = -dy;
 	    } else {
 		if(isok(sx,lsy) && ZAP_POS(rmn = levl[sx][lsy].typ) &&
+		   !closed_door(sx,lsy) &&
 		   (IS_ROOM(rmn) || (isok(sx+dx,lsy) &&
 				     ZAP_POS(levl[sx+dx][lsy].typ))))
 		    bounce = 1;
 		if(isok(lsx,sy) && ZAP_POS(rmn = levl[lsx][sy].typ) &&
+		   !closed_door(lsx,sy) &&
 		   (IS_ROOM(rmn) || (isok(lsx,sy+dy) &&
 				     ZAP_POS(levl[lsx][sy+dy].typ))))
 		    if(!bounce || rn2(2))