From eb8b4253d32f52dab724afd8e6ad95ba984c2e60 Mon Sep 17 00:00:00 2001
From: Chris Honey <chrishoney@gmail.com>
Date: Mon, 28 Jan 2013 04:08:57 -0600
Subject: [PATCH] Prevent cancelling passwall from wasting a turn

Attempting to passwall onto an excluded square and canceling used to waste a
turn. Passwall uses a turn and mp in some cases where you wouldn't want to
passwall, but information is revealed. Due to the way excluded squares work in
unexplored areas, no information is being revealed, so spending a turn and mp
should be considered a bug. This fixes #6571.
---
 crawl-ref/source/player.cc    |  3 +++
 crawl-ref/source/spl-other.cc | 14 ++++++++++++++
 2 files changed, 17 insertions(+)

diff --git a/crawl-ref/source/player.cc b/crawl-ref/source/player.cc
index cfe2a2a..c4c49e7 100644
--- a/crawl-ref/source/player.cc
+++ b/crawl-ref/source/player.cc
@@ -265,6 +265,9 @@ static bool _check_moveto_terrain(const coord_def& p, const string &move_verb,
 
 static bool _check_moveto_exclusion(const coord_def& p, const string &move_verb)
 {
+    if (move_verb == "passwall")
+        return true;
+
     if (is_excluded(p)
         && !is_stair_exclusion(p)
         && !is_excluded(you.pos())
diff --git a/crawl-ref/source/spl-other.cc b/crawl-ref/source/spl-other.cc
index 2ee1e13..74d4d23 100644
--- a/crawl-ref/source/spl-other.cc
+++ b/crawl-ref/source/spl-other.cc
@@ -28,9 +28,11 @@
 #include "potion.h"
 #include "religion.h"
 #include "spl-util.h"
+#include "state.h"
 #include "stuff.h"
 #include "terrain.h"
 #include "transform.h"
+#include "travel.h"
 
 spret_type cast_cure_poison(int pow, bool fail)
 {
@@ -289,6 +291,18 @@ spret_type cast_passwall(const coord_def& delta, int pow, bool fail)
         return SPRET_ABORT;
     }
 
+    // Prevent wasting a turn when cancelling passwall onto an excluded cell
+    if (is_excluded(dest)
+        && !crawl_state.disables[DIS_CONFIRMATIONS])
+    {
+        string prompt = "Really passwall into a travel-excluded area?";
+        if (!yesno(prompt.c_str(), false, 'n'))
+        {
+            canned_msg(MSG_OK);
+            return SPRET_ABORT;
+        }
+    }
+
     fail_check();
 
     // Below here, failing to cast yields information to the
-- 
1.8.0.2