* Dump spells contained in randart spellbooks, marking memorised spells

  with an asterisk.
* Sif Muna no longer gifts the books specific to Kiku and Vehumet
  (Necronomicon, Annihilations, Demonology) though the spells contained
  there-in may crop up in randart books.


git-svn-id: https://crawl-ref.svn.sourceforge.net/svnroot/crawl-ref/trunk@8011 c06c8d41-db1a-0410-9941-cceddc491573

12 files changed, 164 insertions, 129 deletions

diff --git a/crawl-ref/source/chardump.cc b/crawl-ref/source/chardump.cc
index 6f50aa8146..1e614e9b74 100644
--- a/crawl-ref/source/chardump.cc
+++ b/crawl-ref/source/chardump.cc
@@ -653,7 +653,7 @@ static void _sdump_religion(dump_params &par)
     }
 }
 
-static bool dump_item_origin(const item_def &item, int value)
+static bool _dump_item_origin(const item_def &item, int value)
 {
 #define fs(x) (flags & (x))
     const int flags = Options.dump_item_origins;
@@ -661,10 +661,11 @@ static bool dump_item_origin(const item_def &item, int value)
         return (true);
 
     if (fs(IODS_ARTEFACTS)
-            && (is_random_artefact(item) || is_fixed_artefact(item))
-            && item_ident(item, ISFLAG_KNOW_PROPERTIES))
+        && (is_random_artefact(item) || is_fixed_artefact(item))
+        && item_ident(item, ISFLAG_KNOW_PROPERTIES))
+    {
         return (true);
-
+    }
     if (fs(IODS_EGO_ARMOUR) && item.base_type == OBJ_ARMOUR
         && item_type_known( item ))
     {
@@ -682,16 +683,22 @@ static bool dump_item_origin(const item_def &item, int value)
         return (true);
 
     if (fs(IODS_RUNES) && item.base_type == OBJ_MISCELLANY
-            && item.sub_type == MISC_RUNE_OF_ZOT)
+        && item.sub_type == MISC_RUNE_OF_ZOT)
+    {
         return (true);
+    }
 
     if (fs(IODS_RODS) && item.base_type == OBJ_STAVES
-            && item_is_rod(item))
+        && item_is_rod(item))
+    {
         return (true);
+    }
 
     if (fs(IODS_STAVES) && item.base_type == OBJ_STAVES
-            && !item_is_rod(item))
+        && !item_is_rod(item))
+    {
         return (true);
+    }
 
     if (fs(IODS_BOOKS) && item.base_type == OBJ_BOOKS)
         return (true);
@@ -790,7 +797,7 @@ static void _sdump_inventory(dump_params &par)
                         }
 
                         if (origin_describable(you.inv[j])
-                            && dump_item_origin(you.inv[j], ival))
+                            && _dump_item_origin(you.inv[j], ival))
                         {
                             text += "\n" "   (" + origin_desc(you.inv[j]) + ")";
                         }
diff --git a/crawl-ref/source/command.cc b/crawl-ref/source/command.cc
index 1fbab5fdfe..7751761b85 100644
--- a/crawl-ref/source/command.cc
+++ b/crawl-ref/source/command.cc
@@ -1247,58 +1247,6 @@ static bool _append_books(std::string &desc, item_def &item, std::string key)
     return (true);
 }
 
-// Adds a list of all spells contained in a book or rod to its
-// description string.
-static void _append_spells(std::string &desc, const item_def &item)
-{
-    if (!item.has_spells())
-        return;
-
-    desc += "$$Spells                             Type                      Level$";
-
-    for (int j = 0; j < 8; j++)
-    {
-        spell_type stype = which_spell_in_book(item, j);
-        if (stype == SPELL_NO_SPELL)
-            continue;
-
-        std::string name = spell_title(stype);
-        desc += name;
-        for (unsigned int i = 0; i < 35 - name.length(); i++)
-             desc += " ";
-
-        name = "";
-        if (item.base_type == OBJ_STAVES)
-            name += "Evocations";
-        else
-        {
-            bool already = false;
-
-            for (int i = 0; i <= SPTYP_LAST_EXPONENT; i++)
-            {
-                if (spell_typematch( stype, 1 << i ))
-                {
-                    if (already)
-                        name += "/" ;
-
-                    name += spelltype_name( 1 << i );
-                    already = true;
-                }
-            }
-        }
-        desc += name;
-
-        for (unsigned int i = 36; i < 65 - name.length(); i++)
-             desc += " ";
-
-        char sval[3];
-        itoa( spell_difficulty( stype ), sval, 10 );
-        desc += sval;
-        desc += "$";
-    }
-
-}
-
 static bool _do_description(std::string key, std::string type,
                             std::string footer = "")
 {
@@ -1411,7 +1359,7 @@ static bool _do_description(std::string key, std::string type,
                          || get_item_by_name(&mitm[thing_created], name, OBJ_STAVES))
                 {
                     if (!_append_books(desc, mitm[thing_created], key))
-                        _append_spells(desc, mitm[thing_created]);
+                        append_spells(desc, mitm[thing_created]);
                 }
                 else
                     _append_non_item(desc, key);
diff --git a/crawl-ref/source/describe.cc b/crawl-ref/source/describe.cc
index 42bf6aa797..25a95d3f45 100644
--- a/crawl-ref/source/describe.cc
+++ b/crawl-ref/source/describe.cc
@@ -1625,6 +1625,58 @@ static std::string _describe_deck( const item_def &item )
     return (description);
 }
 
+// Adds a list of all spells contained in a book or rod to its
+// description string.
+void append_spells(std::string &desc, const item_def &item)
+{
+    if (!item.has_spells())
+        return;
+
+    desc += "$$Spells                             Type                      Level$";
+
+    for (int j = 0; j < 8; j++)
+    {
+        spell_type stype = which_spell_in_book(item, j);
+        if (stype == SPELL_NO_SPELL)
+            continue;
+
+        std::string name = (is_memorised(stype)) ? "*" : "";
+                    name += spell_title(stype);
+        desc += name;
+        for (unsigned int i = 0; i < 35 - name.length(); i++)
+             desc += " ";
+
+        name = "";
+        if (item.base_type == OBJ_STAVES)
+            name += "Evocations";
+        else
+        {
+            bool already = false;
+
+            for (int i = 0; i <= SPTYP_LAST_EXPONENT; i++)
+            {
+                if (spell_typematch( stype, 1 << i ))
+                {
+                    if (already)
+                        name += "/" ;
+
+                    name += spelltype_name( 1 << i );
+                    already = true;
+                }
+            }
+        }
+        desc += name;
+
+        for (unsigned int i = 36; i < 65 - name.length(); i++)
+             desc += " ";
+
+        char sval[3];
+        itoa( spell_difficulty( stype ), sval, 10 );
+        desc += sval;
+        desc += "$";
+    }
+}
+
 // ========================================================================
 //      Public Functions
 // ========================================================================
@@ -1714,7 +1766,8 @@ std::string get_item_description( const item_def &item, bool verbose,
         description << ".$";
     }
     else if (verbose || (item.base_type != OBJ_WEAPONS
-                         && item.base_type != OBJ_ARMOUR))
+                         && item.base_type != OBJ_ARMOUR
+                         && item.base_type != OBJ_BOOKS))
     {
         description << "$$";
 
@@ -1779,7 +1832,7 @@ std::string get_item_description( const item_def &item, bool verbose,
     std::string desc;
     switch (item.base_type)
     {
-    // Weapons, armour, jewellery might be artefacts.
+    // Weapons, armour, jewellery, books might be artefacts.
     case OBJ_WEAPONS:
         desc = _describe_weapon( item, verbose );
         if (desc.empty())
@@ -1804,6 +1857,22 @@ std::string get_item_description( const item_def &item, bool verbose,
             description << desc;
         break;
 
+    case OBJ_BOOKS:
+        if (!player_can_read_spellbook( item ))
+        {
+            description << "$This book is beyond your current level of "
+                           "understanding.";
+        }
+        else if (!verbose && is_random_artefact( item ))
+        {
+            append_spells( desc, item );
+            if (desc.empty())
+                need_extra_line = false;
+            else
+                description << desc;
+        }
+        break;
+
     case OBJ_MISSILES:
         description << _describe_ammo( item );
         break;
@@ -1905,14 +1974,6 @@ std::string get_item_description( const item_def &item, bool verbose,
             description << _describe_deck( item );
         break;
 
-    case OBJ_BOOKS:
-        if (!player_can_read_spellbook( item ))
-        {
-            description << "$This book is beyond your current level of "
-                           "understanding.";
-        }
-        break;
-
     case OBJ_POTIONS:
 #ifdef DEBUG_BLOOD_POTIONS
         // List content of timer vector for blood potions.
diff --git a/crawl-ref/source/describe.h b/crawl-ref/source/describe.h
index 1b938b6740..ab661c919c 100644
--- a/crawl-ref/source/describe.h
+++ b/crawl-ref/source/describe.h
@@ -27,6 +27,8 @@ enum item_description_type
     NUM_IDESC
 };
 
+void append_spells(std::string &desc, const item_def &item);
+
 // last updated 12may2000 {dlb}
 /* ***********************************************************************
  * called from: chardump - spells4
diff --git a/crawl-ref/source/effects.cc b/crawl-ref/source/effects.cc
index 9b34adb9de..72de9af7fd 100644
--- a/crawl-ref/source/effects.cc
+++ b/crawl-ref/source/effects.cc
@@ -1186,8 +1186,7 @@ static int _find_acquirement_subtype(object_class_type class_wanted,
                     // much too good (most spells, lots of books here,
                     // id wand charges, gives magic resistance),
                     // something will eventually have to be done.  -- bwr
-                    if (best_any >= SK_FIGHTING
-                                && best_any <= SK_STAVES)
+                    if (best_any >= SK_FIGHTING && best_any <= SK_STAVES)
                     {
                         // Fighter mages get the fighting enchantment books
                         if (!you.had_book[BOOK_WAR_CHANTS])
@@ -1275,7 +1274,7 @@ static int _find_acquirement_subtype(object_class_type class_wanted,
                 }
 
                 // If the book is invalid find any valid one.
-                while (book_rarity(type_wanted) == 100)
+                while (type_wanted == BOOK_HEALING)
                     type_wanted = random2(NUM_NORMAL_BOOKS);
                 break;
 
@@ -1423,8 +1422,8 @@ static void _do_book_acquirement(item_def &book, int agent)
     // items() shouldn't make book a randart for acquirement items.
     ASSERT(!is_random_artefact(book));
 
-    // Non-normal books are rare enough without turning them into
-    // randart books.
+    // Non-normal books (i.e. manuals/book of destruction) are rare enough
+    // without turning them into randart books.
     if (book.sub_type > MAX_NORMAL_BOOK)
         return;
 
@@ -1445,36 +1444,35 @@ static void _do_book_acquirement(item_def &book, int agent)
 
         std::vector<int> vec;
         for (int i = 1; i <= 9 && (vec.empty() || i <= max_level); i++)
-        {
             if (!(seen_levels & (1 << i)))
                 vec.push_back(i);
-        }
+
         if (vec.size() > 0)
             level = vec[random2(vec.size())];
         else
             level = -1;
     }
 
-    int choice_weights[4] = {
-                               55, // fixed themed
-                               24, // leave alone
-             level == -1 ? 0 : 12, // fixed level
-        agent == GOD_XOM ? 0 :  6, // manual (too useful for Xom)
-        };
+    int choice = random_choose_weighted(
+            55, BOOK_RANDART_THEME,
+            24, book.sub_type,
+            level == -1 ? 0 : 12, BOOK_RANDART_LEVEL,
+       agent == GOD_XOM ? 0 : 6, BOOK_MANUAL, // too useful for Xom
+            0);
+
+    // No changes.
+    if (choice == book.sub_type)
+        return;
 
-    int choice = choose_random_weighted(choice_weights, choice_weights + 4);
+    book.sub_type = choice;
 
-    switch(choice)
+    switch (choice)
     {
-    case 0:
+    case BOOK_RANDART_THEME:
         make_book_theme_randart(book, 0, 0, 7, 22);
         break;
 
-    case 1:
-        // Leave alone
-        break;
-
-    case 2:
+    case BOOK_RANDART_LEVEL:
     {
         int num_spells = 7 - (level + 1) / 2 + random_range(1, 2);
         make_book_level_randart(book, level, num_spells);
@@ -1482,7 +1480,7 @@ static void _do_book_acquirement(item_def &book, int agent)
     }
 
     // Spell discipline manual
-    case 3:
+    case BOOK_MANUAL:
     {
         int weights[SK_POISON_MAGIC - SK_CONJURATIONS + 1];
         int total_weights = 0;
@@ -1559,15 +1557,13 @@ bool acquirement(object_class_type class_wanted, int agent,
         }
     }
 
-    const bool god_agent = agent > GOD_NO_GOD && agent < NUM_GODS;
-
     if (grid_destroys_items(grd(you.pos())))
     {
         // How sad (and stupid).
         if (!silenced(you.pos()) && !quiet)
             mprf(MSGCH_SOUND, grid_item_destruction_message(grd(you.pos())));
 
-        if (god_agent)
+        if (agent > GOD_NO_GOD && agent < NUM_GODS)
         {
             if (agent == GOD_XOM)
                 simple_god_message(" snickers.", GOD_XOM);
@@ -1596,7 +1592,7 @@ bool acquirement(object_class_type class_wanted, int agent,
 
             // Don't generate randart books in items(), we do that
             // ourselves.
-            int want_arts = class_wanted == OBJ_BOOKS ? 0 : 1;
+            int want_arts = (class_wanted == OBJ_BOOKS ? 0 : 1);
 
             thing_created = items( want_arts, class_wanted, type_wanted, true,
                                    MAKE_GOOD_ITEM, MAKE_ITEM_RANDOM_RACE,
@@ -1661,6 +1657,20 @@ bool acquirement(object_class_type class_wanted, int agent,
                     continue;
                 }
             }
+
+            // Sif Muna shouldn't gift Vehumet or Kiku's special books.
+            // (The spells therein are still fair game for randart books.)
+            if (agent == GOD_SIF_MUNA
+                && doodad.sub_type >= MIN_GOD_ONLY_BOOK
+                && doodad.sub_type <= MAX_GOD_ONLY_BOOK)
+            {
+                ASSERT(doodad.base_type == OBJ_BOOKS);
+
+                // Try again.
+                destroy_item(thing_created);
+                thing_created = NON_ITEM;
+                continue;
+            }
             break;
         }
 
@@ -1822,7 +1832,7 @@ bool acquirement(object_class_type class_wanted, int agent,
             if (is_random_artefact(thing))
             {
                 if (!is_unrandom_artefact(thing)
-                    && !thing.base_type == OBJ_BOOKS)
+                    && thing.base_type != OBJ_BOOKS)
                 {
                     // Give another name that takes god gift into account;
                     // artefact books already do that.
diff --git a/crawl-ref/source/initfile.cc b/crawl-ref/source/initfile.cc
index 14e9e69f57..bbd6dcdc4f 100644
--- a/crawl-ref/source/initfile.cc
+++ b/crawl-ref/source/initfile.cc
@@ -2832,15 +2832,21 @@ void game_options::read_option_line(const std::string &str, bool runscript)
         {
             const std::string &ch = choices[i];
             if (ch == "artefacts" || ch == "artifacts"
-                    || ch == "artefact" || ch == "artifact")
+                || ch == "artefact" || ch == "artifact")
+            {
                 dump_item_origins |= IODS_ARTEFACTS;
+            }
             else if (ch == "ego_arm" || ch == "ego armour"
-                    || ch == "ego_armour")
+                     || ch == "ego_armour")
+            {
                 dump_item_origins |= IODS_EGO_ARMOUR;
+            }
             else if (ch == "ego_weap" || ch == "ego weapon"
-                    || ch == "ego_weapon" || ch == "ego weapons"
-                    || ch == "ego_weapons")
+                     || ch == "ego_weapon" || ch == "ego weapons"
+                     || ch == "ego_weapons")
+            {
                 dump_item_origins |= IODS_EGO_WEAPON;
+            }
             else if (ch == "jewellery" || ch == "jewelry")
                 dump_item_origins |= IODS_JEWELLERY;
             else if (ch == "runes")
diff --git a/crawl-ref/source/items.cc b/crawl-ref/source/items.cc
index 990dd46204..49c376408e 100644
--- a/crawl-ref/source/items.cc
+++ b/crawl-ref/source/items.cc
@@ -1061,7 +1061,7 @@ bool origin_is_god_gift(const item_def& item, god_type *god)
     if (iorig > GOD_NO_GOD && iorig < NUM_GODS)
     {
         *god = static_cast<god_type>(iorig);
-        return(true);
+        return (true);
     }
 
     return (false);
@@ -2570,16 +2570,16 @@ bool item_is_equipped(const item_def &item, bool quiver_too)
 bool item_def::has_spells() const
 {
     return ((base_type == OBJ_BOOKS && item_type_known(*this)
-            && sub_type != BOOK_DESTRUCTION
-            && sub_type != BOOK_MANUAL)
+               && sub_type != BOOK_DESTRUCTION
+               && sub_type != BOOK_MANUAL)
             || count_staff_spells(*this, true) > 1);
 }
 
 int item_def::book_number() const
 {
-    return (base_type == OBJ_BOOKS?   sub_type                             :
-            base_type == OBJ_STAVES?  sub_type + NUM_BOOKS - STAFF_SMITING :
-            -1);
+    return (base_type == OBJ_BOOKS  ? sub_type                             :
+            base_type == OBJ_STAVES ? sub_type + NUM_BOOKS - STAFF_SMITING
+                                    : -1);
 }
 
 bool item_def::cursed() const
diff --git a/crawl-ref/source/makeitem.cc b/crawl-ref/source/makeitem.cc
index bd98b43d61..bd4ee4a76d 100644
--- a/crawl-ref/source/makeitem.cc
+++ b/crawl-ref/source/makeitem.cc
@@ -2424,7 +2424,7 @@ static void _generate_book_item(item_def& item, int allow_uniques,
                 continue;
             }
         }
-        while (book_rarity(item.sub_type) == 100);
+        while (item.sub_type == BOOK_HEALING);
 
         // Tome of destruction: rare!
         if (item_level > 10 && x_chance_in_y(21 + item_level, 7000))
@@ -2664,7 +2664,7 @@ static void _generate_misc_item(item_def& item, int force_type, int item_race)
 
 // Returns item slot or NON_ITEM if it fails.
 int items( int allow_uniques,       // not just true-false,
-                                    //     because of BCR acquirement hack
+                                    // because of BCR acquirement hack
            object_class_type force_class, // desired OBJECTS class {dlb}
            int force_type,          // desired SUBTYPE - enum varies by OBJ
            bool dont_place,         // don't randomly place item on level
@@ -2681,9 +2681,9 @@ int items( int allow_uniques,       // not just true-false,
     // force_ego = SPWPN_VORPAL, and a random weapon of a type
     // appropriate for the vorpal brand will be chosen.
     ASSERT(force_ego <= 0
-           || (force_class == OBJ_WEAPONS || force_class == OBJ_ARMOUR
-                   || force_class == OBJ_MISSILES)
-               && force_type != OBJ_RANDOM);
+           || force_type != OBJ_RANDOM
+              && (force_class == OBJ_WEAPONS || force_class == OBJ_ARMOUR
+                  || force_class == OBJ_MISSILES));
 
     // Find an empty slot for the item (with culling if required).
     int p = get_item_slot(10);
diff --git a/crawl-ref/source/randart.cc b/crawl-ref/source/randart.cc
index 482d732e12..0ba286f991 100644
--- a/crawl-ref/source/randart.cc
+++ b/crawl-ref/source/randart.cc
@@ -1153,7 +1153,7 @@ static bool _init_randart_book(item_def &book)
     ASSERT(book.plus != 0);
 
     god_type god;
-    bool redo = !origin_is_god_gift(book, &god) || god != GOD_XOM;
+    bool redo = (!origin_is_god_gift(book, &god) || god != GOD_XOM);
 
     // Plus and plus2 contain paramaters to make_book_foo_randart()
     // which might get changed after the book has been made into a
@@ -2110,7 +2110,7 @@ bool make_item_randart( item_def &item )
         }
     }
 
-    // This already is a randart.
+    // This item already is a randart.
     if (item.flags & ISFLAG_RANDART)
         return (true);
 
diff --git a/crawl-ref/source/religion.cc b/crawl-ref/source/religion.cc
index d3bc89da58..2ca8d4d9b4 100644
--- a/crawl-ref/source/religion.cc
+++ b/crawl-ref/source/religion.cc
@@ -1987,7 +1987,7 @@ static void _do_god_gift(bool prayed_for)
                 }
 
                 if (gift != NUM_BOOKS
-                    && !(grid_destroys_items(grd(you.pos()))))
+                    && !grid_destroys_items(grd(you.pos())))
                 {
                     if (gift == OBJ_RANDOM)
                         success = acquirement(OBJ_BOOKS, you.religion);
diff --git a/crawl-ref/source/spl-book.cc b/crawl-ref/source/spl-book.cc
index dad9800e5d..b8ecd5d7c0 100644
--- a/crawl-ref/source/spl-book.cc
+++ b/crawl-ref/source/spl-book.cc
@@ -1137,8 +1137,8 @@ void mark_had_book(const item_def &book)
         int      level = book.plus;
         ASSERT(level > 0 && level <= 9);
 
-        if (origin_is_acquirement(book) ||
-            origin_is_god_gift(book, &god) && god == GOD_SIF_MUNA)
+        if (origin_is_acquirement(book)
+            || origin_is_god_gift(book, &god) && god == GOD_SIF_MUNA)
         {
             you.attribute[ATTR_RND_LVL_BOOKS] |= (1 << level);
         }
@@ -1191,6 +1191,7 @@ int read_book( item_def &book, read_book_action_type action )
     // from memorise as well.
 
     set_ident_flags( book, ISFLAG_KNOW_TYPE );
+    set_ident_flags( book, ISFLAG_IDENT_MASK);
 
     return (keyin);
 }
@@ -1714,13 +1715,11 @@ static bool _compare_spells(spell_type a, spell_type b)
     return (strcmp(spell_title(a), spell_title(b)));
 }
 
-static bool _is_memorised(spell_type spell)
+bool is_memorised(spell_type spell)
 {
     for (int i = 0; i < 25; i++)
-    {
         if (you.spells[i] == spell)
             return (true);
-    }
 
     return (false);
 }
@@ -1802,8 +1801,7 @@ static void _get_spell_list(std::vector<spell_type> &spell_list, int level,
 }
 
 
-bool make_book_level_randart(item_def &book, int level,
-                             int num_spells)
+bool make_book_level_randart(item_def &book, int level, int num_spells)
 {
     ASSERT(book.base_type == OBJ_BOOKS);
 
@@ -1815,7 +1813,7 @@ bool make_book_level_randart(item_def &book, int level,
 
     if (!is_random_artefact(book))
     {
-        // Stuf parameters into book.plus and book.plus2, then call
+        // Stuff parameters into book.plus and book.plus2, then call
         // make_item_randart(), which will call us back.
         if (level == -1)
         {
@@ -1922,7 +1920,7 @@ bool make_book_level_randart(item_def &book, int level,
         spell_type spell = spell_list[spell_pos];
         ASSERT(spell != SPELL_NO_SPELL);
 
-        if (avoid_memorised[spell_pos] && _is_memorised(spell))
+        if (avoid_memorised[spell_pos] && is_memorised(spell))
         {
            // Only once.
            avoid_memorised[spell_pos] = false;
@@ -2044,12 +2042,14 @@ static bool _get_weighted_discs(bool completely_random, god_type god,
         }
     }
 
-    do {
+    do
+    {
         disc1 = ok_discs[choose_random_weighted(skill_weights,
                                                 skill_weights + num_discs)];
         disc2 = ok_discs[choose_random_weighted(apt_weights,
                                                 apt_weights + num_discs)];
-    } while(disciplines_conflict(disc1, disc2));
+    }
+    while(disciplines_conflict(disc1, disc2));
 
     return (true);
 }
@@ -2093,7 +2093,7 @@ static void _get_weighted_spells(bool completely_random, god_type god,
             int c = 1;
             if (!you.seen_spell[spell])
                 c = 4;
-            else if (!_is_memorised(spell))
+            else if (!is_memorised(spell))
                 c = 2;
 
             int total_skill = 0;
@@ -2124,7 +2124,7 @@ static void _get_weighted_spells(bool completely_random, god_type god,
 
     int book_pos    = 0;
     int spells_left = spell_list.size();
-    while(book_pos < num_spells && max_levels > 0 && spells_left > 0)
+    while (book_pos < num_spells && max_levels > 0 && spells_left > 0)
     {
         spell_type spell =
             (spell_type) choose_random_weighted(spell_weights,
diff --git a/crawl-ref/source/spl-book.h b/crawl-ref/source/spl-book.h
index 41abf8a158..b43aeddf53 100644
--- a/crawl-ref/source/spl-book.h
+++ b/crawl-ref/source/spl-book.h
@@ -59,6 +59,7 @@ spell_type which_spell_in_book(int sbook_type, int spl);
 
 // returns amount practised (or -1 for abort)
 int staff_spell( int zap_device_2 );
+bool is_memorised(spell_type spell);
 
 bool undead_cannot_memorise(spell_type spell, char being);