a working stone circle boosts magic resistance of people inside.

src/magic.c

@@ -1116,12 +1116,11 @@ variant magic_resistance(const unit * target)
     /* Bonus durch Gebaeude */
     {
         struct building *b = inside_building(target);
-        const struct building_type *btype = building_is_active(b) ? b->type : NULL;
 
         /* gesegneter Steinkreis gibt 30% dazu */
-        if (btype) {
+        if (b && b->type->magresbonus && building_is_active(b)) {
             /* TODO: legacy. building-bonus is an integer-percentage */
-            prob = frac_add(prob, frac_make(btype->magresbonus, 100));
+            prob = frac_add(prob, frac_make(b->type->magresbonus, 100));
         }
     }
 

src/magic.test.c

@@ -507,24 +507,25 @@ static void test_resist_chance(CuTest *tc) {
 static void test_magic_resistance(CuTest *tc) {
     unit *u;
     race *rc;
+    building_type *btype;
 
     test_setup();
+
     rc = test_create_race("human");
     u = test_create_unit(test_create_faction_ex(rc, NULL), test_create_plain(0, 0));
 
+    btype = test_create_buildingtype("stonecircle");
+    btype->magresbonus = 20; /* this building gives +20% magic resistance */
+    u->building = test_create_building(u->region, btype);
+    u->building->flags = BLD_MAINTAINED;
+    CuAssertTrue(tc, frac_equal(frac_make(1, 5), magic_resistance(u)));
+    u->building = NULL;
+
     /* 5% bonus in magic resistance for each magic level */
     set_level(u, SK_MAGIC, 4); /* makes for 20% */
     CuAssertTrue(tc, frac_equal(frac_make(1, 5), magic_resistance(u)));
     set_level(u, SK_MAGIC, 0);
 
-    /* TODO:
-    * - ct_magicresistance
-    * - ct_badmagicresistancezone
-    * - ct_goodmagicresistancezone
-    * - alliedunit
-    * - stone circles
-    */
-
     CuAssertTrue(tc, frac_equal(rc->magres, magic_resistance(u)));
     rc->magres = frac_one;
     CuAssert(tc, "magic resistance is capped at 0.9", frac_equal(magic_resistance(u), frac_make(9, 10)));

src/spells/magicresistance.test.c

@@ -24,6 +24,10 @@
 #include <string.h>
 #include <assert.h>
 
+/* TODO:
+ * - ct_magicresistance on buildings
+ * - stone circles
+ */
 
 static void test_magicresistance_curse_effects(CuTest *tc) {
     struct region *r;
@@ -114,6 +118,9 @@ static void test_magicresistance_unit(CuTest *tc) {
     test_teardown();
 }
 
+/** 
+ * Test for spell "Heimstein"
+ */
 static void test_magicresistance_building(CuTest *tc) {
     struct region *r;
     struct faction *f1;
@@ -130,7 +137,7 @@ static void test_magicresistance_building(CuTest *tc) {
     u1 = test_create_unit(f1, r);
 
     b1 = test_create_building(r, NULL);
-
+    u1->building = b1;
     c = create_curse(u1, &b1->attribs, &ct_magicresistance, 10, 20, 30, 0);
     CuAssertPtrNotNull(tc, b1->attribs);
     CuAssertPtrEquals(tc, (void *)&at_curse, (void *)b1->attribs->type);