ceiling hiders vs '>'

Poly'd hero hiding on the ceiling was told "you can't go down here"
if using '>' at a spot that didn't have down stairs, trap door, hole,
or pit.  Let '>' bring a ceiling hider out of hiding; lurker above
resumes flying, piercer falls to floor or whatever is underneath it.

doc/fixes36.4

@@ -1,4 +1,4 @@
-$NHDT-Branch: NetHack-3.6 $:$NHDT-Revision: 1.11 $ $NHDT-Date: 1576635242 2019/12/18 02:14:02 $
+$NHDT-Branch: NetHack-3.6 $:$NHDT-Revision: 1.12 $ $NHDT-Date: 1576638499 2019/12/18 03:08:19 $
 
 fixes36.4 contains a terse summary of changes made to 3.6.3 in order to
 produce 3.6.4.
@@ -19,6 +19,9 @@ fix potential buffer overflow when parsing run-time configuration file
 wizard mode wishing for terrain would leave it unmapped if done while blind
 wizard mode terrain wish could leave hero in water (severe vision limits) or
 	in lava (trapped, sinking) which wasn't there any more
+flying hero can go down (via '>') holes or trap doors instead of escaping trap
+polymorphed hero hiding on the ceiling can now use '>' to unhide instead of
+	being told "you can't go down here"
 
 
 Platform- and/or Interface-Specific Fixes or Features

src/do.c

@@ -1,4 +1,4 @@
-/* NetHack 3.6	do.c	$NHDT-Date: 1576181796 2019/12/12 20:16:36 $  $NHDT-Branch: NetHack-3.6 $:$NHDT-Revision: 1.197 $ */
+/* NetHack 3.6	do.c	$NHDT-Date: 1576638499 2019/12/18 03:08:19 $  $NHDT-Branch: NetHack-3.6 $:$NHDT-Revision: 1.198 $ */
 /* Copyright (c) Stichting Mathematisch Centrum, Amsterdam, 1985. */
 /*-Copyright (c) Derek S. Ray, 2015. */
 /* NetHack may be freely redistributed.  See license for details. */
@@ -1000,6 +1000,24 @@ dodown()
                                                     : surface(u.ux, u.uy));
         return 0; /* didn't move */
     }
+
+    if (Upolyd && ceiling_hider(&mons[u.umonnum]) && u.uundetected) {
+        u.uundetected = 0;
+        if (Flying) { /* lurker above */
+            You("fly out of hiding.");
+        } else { /* piercer */
+            You("drop to the %s.", surface(u.ux, u.uy));
+            if (is_pool_or_lava(u.ux, u.uy)) {
+                pooleffects(FALSE);
+            } else {
+                (void) pickup(1);
+                if ((trap = t_at(u.ux, u.uy)) != 0)
+                    dotrap(trap, TOOKPLUNGE);
+            }
+        }
+        return 1; /* came out of hiding; might need '>' again to go down */
+    }
+
     if (!stairs_down && !ladder_down) {
         trap = t_at(u.ux, u.uy);
         if (trap && (uteetering_at_seen_pit(trap) || uescaped_shaft(trap))) {

src/hack.c

@@ -1,4 +1,4 @@
-/* NetHack 3.6	hack.c	$NHDT-Date: 1568509227 2019/09/15 01:00:27 $  $NHDT-Branch: NetHack-3.6 $:$NHDT-Revision: 1.216 $ */
+/* NetHack 3.6	hack.c	$NHDT-Date: 1576638500 2019/12/18 03:08:20 $  $NHDT-Branch: NetHack-3.6 $:$NHDT-Revision: 1.220 $ */
 /* Copyright (c) Stichting Mathematisch Centrum, Amsterdam, 1985. */
 /*-Copyright (c) Derek S. Ray, 2015. */
 /* NetHack may be freely redistributed.  See license for details. */
@@ -2124,6 +2124,10 @@ boolean newspot;             /* true if called by spoteffects */
         }
         /* not mounted */
 
+        /* if hiding on ceiling then don't automatically enter pool */
+        if (Upolyd && ceiling_hider(&mons[u.umonnum]) && u.uundetected)
+            return FALSE;
+
         /* drown(),lava_effects() return true if hero changes
            location while surviving the problem */
         if (is_lava(u.ux, u.uy)) {

src/objnam.c

@@ -1,4 +1,4 @@
-/* NetHack 3.6	objnam.c	$NHDT-Date: 1576635242 2019/12/18 02:14:02 $  $NHDT-Branch: NetHack-3.6 $:$NHDT-Revision: 1.256 $ */
+/* NetHack 3.6	objnam.c	$NHDT-Date: 1576638500 2019/12/18 03:08:20 $  $NHDT-Branch: NetHack-3.6 $:$NHDT-Revision: 1.257 $ */
 /* Copyright (c) Stichting Mathematisch Centrum, Amsterdam, 1985. */
 /*-Copyright (c) Robert Patrick Rankin, 2011. */
 /* NetHack may be freely redistributed.  See license for details. */
@@ -3733,7 +3733,7 @@ struct obj *no_wish;
             del_engr_at(x, y);
             pline("A pool of molten lava.");
             if (!(Levitation || Flying))
-                (void) lava_effects();
+                pooleffects(FALSE);
             madeterrain = TRUE;
         } else if (!BSTRCMPI(bp, p - 5, "altar")) {
             aligntyp al;
@@ -3770,12 +3770,15 @@ struct obj *no_wish;
         }
 
         if (madeterrain) {
-            feel_newsym(x, y);
+            feel_newsym(x, y); /* map the spot where the wish occurred */
-            if (u.uinwater && !is_pool(x, y)) {
+            /* hero started at <x,y> but might not be there anymore (create
+               lava, decline to die, and get teleported away to safety) */
+            if (u.uinwater && !is_pool(u.ux, u.uy)) {
                 u.uinwater = 0; /* leave the water */
                 docrt();
                 vision_full_recalc = 1;
-            } else if (u.utrap && u.utraptype == TT_LAVA && !is_lava(x, y)) {
+            } else if (u.utrap && u.utraptype == TT_LAVA
+                       && !is_lava(u.ux, u.uy)) {
                 reset_utrap(FALSE);
             }
             /* cast 'const' away; caller won't modify this */

src/trap.c

@@ -1,4 +1,4 @@
-/* NetHack 3.6	trap.c	$NHDT-Date: 1576635243 2019/12/18 02:14:03 $  $NHDT-Branch: NetHack-3.6 $:$NHDT-Revision: 1.328 $ */
+/* NetHack 3.6	trap.c	$NHDT-Date: 1576638501 2019/12/18 03:08:21 $  $NHDT-Branch: NetHack-3.6 $:$NHDT-Revision: 1.329 $ */
 /* Copyright (c) Stichting Mathematisch Centrum, Amsterdam, 1985. */
 /*-Copyright (c) Robert Patrick Rankin, 2013. */
 /* NetHack may be freely redistributed.  See license for details. */
@@ -489,8 +489,9 @@ unsigned ftflags;
         ; /* KMH -- You can't escape the Sokoban level traps */
     else if (Levitation || u.ustuck
              || (!Can_fall_thru(&u.uz) && !levl[u.ux][u.uy].candig)
-             || ((Flying || is_clinger(youmonst.data))
+             || ((Flying || is_clinger(youmonst.data)
-                    && !(ftflags & TOOKPLUNGE))
+                  || (ceiling_hider(youmonst.data) && u.uundetected))
+                 && !(ftflags & TOOKPLUNGE))
              || (Inhell && !u.uevent.invoked && newlevel == bottom)) {
         dont_fall = "don't fall in.";
     } else if (youmonst.data->msize >= MZ_HUGE) {
@@ -5388,7 +5389,10 @@ sink_into_lava()
     static const char sink_deeper[] = "You sink deeper into the lava.";
 
     if (!u.utrap || u.utraptype != TT_LAVA) {
-        ; /* do nothing; this shouldn't happen */
+        ; /* do nothing; this usually won't happen but could after
+           * polymorphing from a flier into a ceiling hider and then hiding;
+           * allmain() only checks whether the hero is at a lava location,
+           * not whether he or she is currently sinking */
     } else if (!is_lava(u.ux, u.uy)) {
         reset_utrap(FALSE); /* this shouldn't happen either */
     } else if (!u.uinvulnerable) {