added a test for pay_spell so I don't break it.

src/bindings/bind_unit.c

@@ -483,27 +483,20 @@ static int tolua_unit_castspell(lua_State * L)
   return 0;
 }
 
-static int unit_addspell(unit * u, const char *name)
-{
-  sc_mage *m = get_mage(u);
-  spell *spadd = find_spell(name);
-
-  if (!spadd) {
-    log_error("spell %s could not be found\n", name);
-    return EINVAL;
-  } else {
-    quicklist **starget = get_spelllist(m, u->faction);
-    add_spell(starget, spadd);
-    add_spellname(m, spadd);
-  }
-  return 0;
-}
-
 static int tolua_unit_addspell(lua_State * L)
 {
-  unit *self = (unit *) tolua_tousertype(L, 1, 0);
+  unit *u = (unit *) tolua_tousertype(L, 1, 0);
   const char *str = tolua_tostring(L, 2, 0);
-  int err = unit_addspell(self, str);
+  int err = 0;
+  spell *sp = find_spell(str);
+
+  if (!sp) {
+    log_error("spell %s could not be found\n", str);
+    return EINVAL;
+  } else {
+    unit_add_spell(u, 0, sp);
+  }
+
   lua_pushinteger(L, err);
   return 1;
 }

src/kernel/equipment.c

@@ -130,29 +130,25 @@ void equip_unit_mask(struct unit *u, const struct equipment *eq, int mask)
   if (eq) {
 
     if (mask & EQUIP_SKILLS) {
-      skill_t sk;
+      int sk;
       for (sk = 0; sk != MAXSKILLS; ++sk) {
         if (eq->skills[sk] != NULL) {
           int i = dice_rand(eq->skills[sk]);
           if (i > 0)
-            set_level(u, sk, i);
+            set_level(u, (skill_t)sk, i);
         }
       }
     }
 
     if (mask & EQUIP_SPELLS) {
       if (eq->spellbook) {
-        sc_mage *m = get_mage(u);
         quicklist * ql = eq->spellbook->spells;
         int qi;
+        sc_mage * mage = get_mage(u);
 
-        if (!m) {
-          m = create_mage(u, u->faction?u->faction->magiegebiet:M_GRAY);
-        }
         for (qi = 0; ql; ql_advance(&ql, &qi, 1)) {
           spellbook_entry *sbe = (spellbook_entry *) ql_get(ql, qi);
-          add_spell(&m->spells, sbe->sp);
+          unit_add_spell(u, mage, sbe->sp);
-          add_spellname(m, sbe->sp);
         }
       }
     }

src/kernel/magic_test.c

@@ -2,9 +2,13 @@
 
 #include <kernel/types.h>
 #include <kernel/faction.h>
+#include <kernel/item.h>
 #include <kernel/magic.h>
+#include <kernel/region.h>
 #include <kernel/spell.h>
 #include <kernel/spellbook.h>
+#include <kernel/unit.h>
+#include <kernel/pool.h>
 #include <util/quicklist.h>
 #include <util/language.h>
 
@@ -64,10 +68,52 @@ void test_spellbooks(CuTest * tc)
   /* CuAssertPtrEquals(tc, 0, spellbook_get(herp, sname)); */
 }
 
+void test_pay_spell(CuTest * tc)
+{
+  spell *sp;
+  unit * u;
+  faction * f;
+  region * r;
+
+  test_cleanup();
+  test_create_world();
+  r = findregion(0, 0);
+  f = test_create_faction(0);
+  u = test_create_unit(f, r);
+  CuAssertPtrNotNull(tc, u);
+
+  sp = create_spell("testspell", 0);
+  CuAssertPtrNotNull(tc, sp);
+
+  sp->components = (spell_component *) calloc(4, sizeof(spell_component));
+  sp->components[0].amount = 1;
+  sp->components[0].type = rt_find("money");
+  sp->components[0].cost = SPC_FIX;
+  sp->components[1].amount = 1;
+  sp->components[1].type = rt_find("aura");
+  sp->components[1].cost = SPC_LEVEL;
+  sp->components[2].amount = 1;
+  sp->components[2].type = rt_find("horse");
+  sp->components[2].cost = SPC_LINEAR;
+
+  set_level(u, SK_MAGIC, 5);
+  unit_add_spell(u, 0, sp);
+
+  change_resource(u, rt_find("money"), 1); /* fix costs of 1 money */
+  change_resource(u, rt_find("aura"), 3); /* leveled costs of 3 money */
+  change_resource(u, rt_find("horse"), 3); /* leveled costs of 3 money */
+
+  pay_spell(u, sp, 3, 1);
+  CuAssertIntEquals(tc, 0, get_resource(u, rt_find("money")));
+  CuAssertIntEquals(tc, 0, get_resource(u, rt_find("aura")));
+  CuAssertIntEquals(tc, 0, get_resource(u, rt_find("horse")));
+}
+
 CuSuite *get_magic_suite(void)
 {
   CuSuite *suite = CuSuiteNew();
   SUITE_ADD_TEST(suite, test_updatespells);
   SUITE_ADD_TEST(suite, test_spellbooks);
+  SUITE_ADD_TEST(suite, test_pay_spell);
   return suite;
 }

src/kernel/unit.c

@@ -30,6 +30,7 @@ OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 #include "plane.h"
 #include "race.h"
 #include "region.h"
+#include "spell.h"
 #include "save.h"
 #include "ship.h"
 #include "skill.h"
@@ -1724,3 +1725,15 @@ const struct race *u_irace(const struct unit *u)
   }
   return u->race;
 }
+
+void unit_add_spell(unit * u, sc_mage * m, struct spell * sp)
+{
+  sc_mage *mage = m ? m : get_mage(u);
+
+  if (!mage) {
+    log_debug("adding new spell %s to a previously non-mage unit %s\n", sp->sname, unitname(u));
+    mage = create_mage(u, u->faction?u->faction->magiegebiet:M_GRAY);
+  }
+  add_spell(&mage->spells, sp);
+  add_spellname(mage, sp);
+}

src/kernel/unit.h

@@ -231,6 +231,8 @@ extern "C" {
   int unit_max_hp(const struct unit *u);
   void scale_number(struct unit *u, int n);
 
+  void unit_add_spell(struct unit * u, struct sc_mage * m, struct spell * sp);
+
   extern struct attrib_type at_creator;
 #ifdef __cplusplus
 }