Fix bug [2874791], Merfolk stat change issues

Fix some conditions causing permanent stat loss or gain for Mf with
stat modifying boots.

Unmerge boots when the player starts levitating or flying on a water
square.

Use move_player_to_grid in blink, semi-controlled blink, and
teleportation.

Also fix a bug where Mf could random teleport into solid walls.

4 files changed, 53 insertions, 27 deletions

diff --git a/crawl-ref/source/it_use2.cc b/crawl-ref/source/it_use2.cc
index 84cdc0b4ed..5d3f4e795b 100644
--- a/crawl-ref/source/it_use2.cc
+++ b/crawl-ref/source/it_use2.cc
@@ -31,6 +31,8 @@ REVISION("$Rev$");
 #include "spl-mis.h"
 #include "spl-util.h"
 #include "stuff.h"
+#include "terrain.h"
+#include "transfor.h"
 #include "tutorial.h"
 #include "view.h"
 #include "xom.h"
@@ -243,6 +245,13 @@ bool potion_effect(potion_type pot_eff, int pow, bool drank_it, bool was_known)
             }
         }
 
+        // Merfolk boots unmeld if levitation takes us out of water
+        if(!player_is_airborne() && you.species == SP_MERFOLK
+           && grid_is_water(grd(you.pos())))
+        {
+            unmeld_one_equip(EQ_BOOTS);
+        }
+
         you.duration[DUR_LEVITATION] += 25 + random2(pow);
 
         if (you.duration[DUR_LEVITATION] > 100)
diff --git a/crawl-ref/source/spells1.cc b/crawl-ref/source/spells1.cc
index d480f36430..57b01695a7 100644
--- a/crawl-ref/source/spells1.cc
+++ b/crawl-ref/source/spells1.cc
@@ -234,19 +234,25 @@ void random_blink(bool allow_partial_control, bool override_abyss)
 #endif
     else
     {
+        // Going to assume that move_player_to_grid works, (it should
+        // because terrain type etc. was already checked). could result
+        // in awkward messaging if it cancels for some reason but it's
+        // probably better than getting the blink message after any Mf
+        // transform messages all the time -cao
         mpr("You blink.");
-
-        success = true;
-
-        // Leave a purple cloud.
-        place_cloud(CLOUD_PURP_SMOKE, you.pos(), 1 + random2(3), KC_YOU);
-        you.moveto(target);
-
-        if (you.level_type == LEVEL_ABYSS)
+        coord_def origin = you.pos();
+        success = move_player_to_grid(target, false, true, true);
+        if(success)
         {
-            abyss_teleport(false);
-            if (you.pet_target != MHITYOU)
-                you.pet_target = MHITNOT;
+            // Leave a purple cloud.
+            place_cloud(CLOUD_PURP_SMOKE, origin, 1 + random2(3), KC_YOU);
+
+            if (you.level_type == LEVEL_ABYSS)
+            {
+                abyss_teleport(false);
+                if (you.pet_target != MHITYOU)
+                    you.pet_target = MHITNOT;
+            }
         }
     }
 
@@ -1438,6 +1444,13 @@ void cast_fly(int power)
             mpr("You swoop lightly up into the air.");
         else
             mpr("You fly up into the air.");
+
+        // Merfolk boots unmeld if flight takes us out of water
+        if(you.species == SP_MERFOLK && grid_is_water(grd(you.pos())))
+        {
+            unmeld_one_equip(EQ_BOOTS);
+        }
+
     }
     else
         mpr("You feel more buoyant.");
diff --git a/crawl-ref/source/spells3.cc b/crawl-ref/source/spells3.cc
index 6facccd714..b6b07dcf85 100644
--- a/crawl-ref/source/spells3.cc
+++ b/crawl-ref/source/spells3.cc
@@ -1511,25 +1511,24 @@ static bool _teleport_player(bool allow_control, bool new_abyss_area)
             if (!see_grid(pos))
                 large_change = true;
 
-            // Leave a purple cloud.
-            place_cloud(CLOUD_PURP_SMOKE, you.pos(), 1 + random2(3), KC_YOU);
-
-            you.moveto(pos);
-
             // Merfolk should be able to control-tele into deep water.
-            if (grd(you.pos()) != DNGN_FLOOR
-                    && grd(you.pos()) != DNGN_SHALLOW_WATER
+            if (grd(pos) != DNGN_FLOOR
+                    && grd(pos) != DNGN_SHALLOW_WATER
                     && (you.species != SP_MERFOLK
-                        || grd(you.pos()) != DNGN_DEEP_WATER)
-                || monster_at(you.pos())
-                || env.cgrid(you.pos()) != EMPTY_CLOUD)
+                        || grd(pos) != DNGN_DEEP_WATER)
+                || monster_at(pos)
+                || env.cgrid(pos) != EMPTY_CLOUD)
             {
                 is_controlled = false;
                 large_change  = false;
             }
             else
             {
+                // Leave a purple cloud.
+                place_cloud(CLOUD_PURP_SMOKE, you.pos(), 1 + random2(3), KC_YOU);
+
                 // Controlling teleport contaminates the player. - bwr
+                move_player_to_grid(pos, false, true, true);
                 contaminate_player(1, true);
             }
         }
@@ -1574,7 +1573,7 @@ static bool _teleport_player(bool allow_control, bool new_abyss_area)
         while (grd(newpos) != DNGN_FLOOR
                    && grd(newpos) != DNGN_SHALLOW_WATER
                    && (you.species != SP_MERFOLK
-                       || grd(you.pos()) != DNGN_DEEP_WATER)
+                       || grd(newpos) != DNGN_DEEP_WATER)
                || monster_at(newpos)
                || env.cgrid(newpos) != EMPTY_CLOUD
                || need_distance_check && (newpos - centre).abs() < 34*34);
@@ -1592,7 +1591,7 @@ static bool _teleport_player(bool allow_control, bool new_abyss_area)
         // Leave a purple cloud.
         place_cloud(CLOUD_PURP_SMOKE, you.pos(), 1 + random2(3), KC_YOU);
 
-        you.moveto(newpos);
+        move_player_to_grid(newpos, false, true, true);
     }
 
     if (large_change)
diff --git a/crawl-ref/source/spells4.cc b/crawl-ref/source/spells4.cc
index 43966336b2..5fe91b53bd 100644
--- a/crawl-ref/source/spells4.cc
+++ b/crawl-ref/source/spells4.cc
@@ -1980,11 +1980,16 @@ static int _quadrant_blink(coord_def where, int pow, int, actor *)
     if (!found)
         return(0);
 
-    // Leave a purple cloud.
-    place_cloud(CLOUD_PURP_SMOKE, you.pos(), 1 + random2(3), KC_YOU);
+    coord_def origin = you.pos();
+    int res = move_player_to_grid(target, false, true, true);
 
-    you.moveto(target);
-    return 1;
+    if(res)
+    {
+        // Leave a purple cloud.
+        place_cloud(CLOUD_PURP_SMOKE, origin, 1 + random2(3), KC_YOU);
+    }
+
+    return res;
 }
 
 int cast_semi_controlled_blink(int pow)