Lava walls cover objects

Items landing into a wall of lava are covered up by it.
Kicking behaves the same as wall of water: splashes,
but doesn't move the item.

include/display.h

@@ -216,7 +216,8 @@
  * "cover" any objects or traps that might be there.
  */
 #define covers_objects(xx, yy) \
-    ((is_pool(xx, yy) && !Underwater) || (levl[xx][yy].typ == LAVAPOOL))
+    ((is_pool(xx, yy) && !Underwater) || (levl[xx][yy].typ == LAVAPOOL) \
+      || (levl[xx][yy].typ == LAVAWALL))
 
 #define covers_traps(xx, yy) covers_objects(xx, yy)
 

src/dokick.c

@@ -1137,9 +1137,11 @@ dokick(void)
         return ECMD_TIME;
     }
     (void) unmap_invisible(x, y);
-    if (is_pool(x, y) ^ !!u.uinwater) {
+    if ((is_pool(x, y) || gm.maploc->typ == LAVAWALL) ^ !!u.uinwater) {
         /* objects normally can't be removed from water by kicking */
-        You("splash some %s around.", hliquid("water"));
+        You("splash some %s around.",
+            hliquid(is_pool(x, y) ? "water" : "lava"));
+        /* pretend the kick is fast enough for lava not to burn */
         return ECMD_TIME;
     }