Apply r6500 to 0.4.

git-svn-id: https://crawl-ref.svn.sourceforge.net/svnroot/crawl-ref/branches/stone_soup-0.4@6501 c06c8d41-db1a-0410-9941-cceddc491573

3 files changed, 25 insertions, 7 deletions

diff --git a/crawl-ref/source/misc.cc b/crawl-ref/source/misc.cc
index 7e23bd12e7..4dd1b21753 100644
--- a/crawl-ref/source/misc.cc
+++ b/crawl-ref/source/misc.cc
@@ -1623,6 +1623,8 @@ void up_stairs(dungeon_feature_type force_stair,
              branches[you.where_are_you].longname);
     }
 
+    int stair_x = you.x_pos, stair_y = you.y_pos;
+
 #ifdef USE_TILE
     const bool newlevel =
 #endif
@@ -1677,8 +1679,6 @@ void up_stairs(dungeon_feature_type force_stair,
                         travel_cache.get_level_info(new_level_id);
             new_level_info.update();
 
-            int stair_x = you.x_pos, stair_y = you.y_pos;
-
             // First we update the old level's stair.
             level_pos lp;
             lp.id    = new_level_id;
@@ -1698,12 +1698,12 @@ void up_stairs(dungeon_feature_type force_stair,
             if (new_level_id == BRANCH_MAIN_DUNGEON
                 && old_level_id == BRANCH_VESTIBULE_OF_HELL)
             {
-                lp.id.depth = -1;
-                lp.pos.x = lp.pos.y = -1;
-                guess = true;
+                old_level_info.clear_stairs(DNGN_EXIT_HELL);
+            }
+            else
+            {
+                old_level_info.update_stair(stair_x, stair_y, lp, guess);
             }
-
-            old_level_info.update_stair(you.x_pos, you.y_pos, lp, guess);
 
             // We *guess* that going up a staircase lands us on a downstair,
             // and that we can descend that downstair and get back to where we
diff --git a/crawl-ref/source/travel.cc b/crawl-ref/source/travel.cc
index e8fbe6dc2b..680c66f191 100644
--- a/crawl-ref/source/travel.cc
+++ b/crawl-ref/source/travel.cc
@@ -3185,6 +3185,21 @@ void LevelInfo::sync_branch_stairs(const stair_info *si)
     }
 }
 
+void LevelInfo::clear_stairs(dungeon_feature_type grid)
+{
+    for (int i = 0, size = stairs.size(); i < size; ++i)
+    {
+        stair_info &si = stairs[i];
+        if (si.grid != grid)
+            continue;
+
+        si.destination.id.depth = -1;
+        si.destination.pos.x = -1;
+        si.destination.pos.y = -1;
+        si.guessed_pos = true;
+    }
+}
+
 stair_info *LevelInfo::get_stair(int x, int y)
 {
     const coord_def c(x, y);
diff --git a/crawl-ref/source/travel.h b/crawl-ref/source/travel.h
index 8f42f83cac..752c285044 100644
--- a/crawl-ref/source/travel.h
+++ b/crawl-ref/source/travel.h
@@ -486,6 +486,9 @@ struct LevelInfo
     // Updates/creates a StairInfo for the stair at (x, y) in grid coordinates
     void update_stair(int x, int y, const level_pos &p, bool guess = false);
 
+    // Clears all stair info for stairs matching this grid type.
+    void clear_stairs(dungeon_feature_type grid);
+
     // Returns true if the given branch is known to be accessible from the
     // current level.
     bool is_known_branch(unsigned char branch) const;