fix #4341 - jousting while trapped

doc/fixes3-7-0.txt

@@ -2129,6 +2129,9 @@ when game ended with 'force_invmenu' On, final disclosure of inventory would
 	contain spurious menu entry "? - (list likely candidates)"
 avoid reporting "a gold pieces appears next to you" for mimic
 don't try to split a pudding that got jousted into a hole and is off the map
+mounted hero was able to deliver joust hits when trapped
+timer sanity check for melting ice gave false complaint about non-ice for
+	frozen moat under open drawbridge
 
 
 Fixes to 3.7.0-x Platform and/or Interface Problems Exposed Via git Repository

src/uhitm.c

@@ -2072,6 +2072,11 @@ joust(struct monst *mon, /* target */
     /* sanity check; lance must be wielded in order to joust */
     if (obj != uwep && (obj != uswapwep || !u.twoweap))
         return 0;
+    /* can't joust while trapped--not enough room to maneuver;
+     * TODO? if the steed is trapped in a pit, perhaps the hero ought to be
+     * able to joust against a monster that's in a conjoined pit */
+    if (u.utrap)
+        return 0;
 
     /* if using two weapons, use worse of lance and two-weapon skills */
     skill_rating = P_SKILL(weapon_type(obj)); /* lance skill */