Apply trunk r10287 to 0.5.

git-svn-id: https://crawl-ref.svn.sourceforge.net/svnroot/crawl-ref/branches/stone_soup-0.5@10288 c06c8d41-db1a-0410-9941-cceddc491573

4 files changed, 9 insertions, 6 deletions

diff --git a/crawl-ref/source/decks.cc b/crawl-ref/source/decks.cc
index 825ce9601f..ff625495de 100644
--- a/crawl-ref/source/decks.cc
+++ b/crawl-ref/source/decks.cc
@@ -2195,7 +2195,8 @@ static void _experience_card(int power, deck_rarity_type rarity)
 
 static void _remove_bad_mutation()
 {
-    if (!delete_mutation(RANDOM_BAD_MUTATION, false))
+    // Ensure that only bad mutations are removed.
+    if (!delete_mutation(RANDOM_BAD_MUTATION, false, false, false, true))
         mpr("You feel transcendent for a moment.");
 }
 
diff --git a/crawl-ref/source/mutation.cc b/crawl-ref/source/mutation.cc
index c8561d0878..4d9ea1e480 100644
--- a/crawl-ref/source/mutation.cc
+++ b/crawl-ref/source/mutation.cc
@@ -2142,7 +2142,7 @@ bool mutate(mutation_type which_mutation, bool failMsg,
                 return (false);
             else
                 return (delete_mutation(RANDOM_MUTATION, failMsg,
-                                        force_mutation, non_fatal));
+                                        force_mutation, false, non_fatal));
         }
     }
 
@@ -2401,7 +2401,7 @@ static bool _delete_single_mutation_level(mutation_type mutat)
 
 bool delete_mutation(mutation_type which_mutation, bool failMsg,
                      bool force_mutation, bool god_gift,
-                     bool non_fatal)
+                     bool disallow_mismatch, bool non_fatal)
 {
     ASSERT(!non_fatal || _is_random(which_mutation));
 
@@ -2470,7 +2470,7 @@ bool delete_mutation(mutation_type which_mutation, bool failMsg,
                 (which_mutation == RANDOM_GOOD_MUTATION && mdef.bad)
                     || (which_mutation == RANDOM_BAD_MUTATION && !mdef.bad);
 
-            if (mismatch && !one_chance_in(10))
+            if (mismatch && (disallow_mismatch || !one_chance_in(10)))
                 continue;
 
             break;
diff --git a/crawl-ref/source/mutation.h b/crawl-ref/source/mutation.h
index 0a1d3b082d..a538d01e68 100644
--- a/crawl-ref/source/mutation.h
+++ b/crawl-ref/source/mutation.h
@@ -45,7 +45,7 @@ formatted_string describe_mutations();
 
 bool delete_mutation(mutation_type which_mutation, bool failMsg = true,
                      bool force_mutation = false, bool god_gift = false,
-                     bool non_fatal = false);
+                     bool disallow_mismatch = false, bool non_fatal = false);
 
 bool delete_all_mutations();
 
diff --git a/crawl-ref/source/religion.cc b/crawl-ref/source/religion.cc
index b4af6c1e12..952d405459 100644
--- a/crawl-ref/source/religion.cc
+++ b/crawl-ref/source/religion.cc
@@ -4237,8 +4237,10 @@ static void _zin_remove_good_mutations()
 
     for (int i = 7; i >= 0; --i)
     {
+        // Ensure that only good mutations are removed.
         if (i <= random2(10)
-            && delete_mutation(RANDOM_GOOD_MUTATION, failMsg, false, true))
+            && delete_mutation(RANDOM_GOOD_MUTATION, failMsg, false, true,
+                               true))
         {
             success = true;
         }