https://bugs.eressea.de/view.php?id=2166

* fix magic resistance calculation in calculate_armor.
* add related tests.
* refactor BF_CANATTACK -> BF_NO_ATTACK because it is easier.

src/battle.c

@@ -1181,7 +1181,7 @@ terminate(troop dt, troop at, int type, const char *damage, bool missile)
     const weapon_type *dwtype = NULL;
     const weapon_type *awtype = NULL;
     const weapon *weapon;
-    double res = 0.0;
+    double res = 1.0;
 
     int rda, sk = 0, sd;
     bool magic = false;
@@ -3996,7 +3996,7 @@ static bool start_battle(region * r, battle ** bp)
                         continue;
                     }
 
-                    if ((u_race(u)->battle_flags & BF_CANATTACK) == 0) {
+                    if (u_race(u)->battle_flags & BF_NO_ATTACK) {
                         ADDMSG(&u->faction->msgs, msg_feedback(u, ord, "race_no_attack",
                             "race", u_race(u)));
                         continue;

src/battle.test.c

@@ -248,6 +248,7 @@ static void test_calculate_armor(CuTest * tc)
     i_change(&du->items, ishield, 1);
     i_change(&du->items, ichain, 1);
     dt.fighter = setup_fighter(&b, du);
+    rc->battle_flags &= ~BF_EQUIPMENT;
     CuAssertIntEquals_Msg(tc, "require BF_EQUIPMENT", 1, calculate_armor(dt, 0, 0, 0));
     free_battle(b);
 
@@ -274,6 +275,70 @@ static void test_calculate_armor(CuTest * tc)
     test_cleanup();
 }
 
+static void test_magic_resistance(CuTest *tc)
+{
+    troop dt;
+    battle *b;
+    region *r;
+    unit *du;
+    weapon_type *wtype;
+    armor_type *ashield, *achain;
+    item_type *ibelt, *ishield, *ichain;
+    race *rc;
+    double magres = 0.0;
+
+    test_cleanup();
+    r = test_create_region(0, 0, 0);
+    ibelt = it_get_or_create(rt_get_or_create("trollbelt"));
+    ishield = it_get_or_create(rt_get_or_create("shield"));
+    ashield = new_armortype(ishield, 0.0, 0.5, 1, ATF_SHIELD);
+    ichain = it_get_or_create(rt_get_or_create("chainmail"));
+    achain = new_armortype(ichain, 0.0, 0.5, 3, ATF_NONE);
+    wtype = new_weapontype(it_get_or_create(rt_get_or_create("sword")), 0, 0.5, 0, 0, 0, 0, SK_MELEE, 1);
+    rc = test_create_race("human");
+    du = test_create_unit(test_create_faction(rc), r);
+    dt.index = 0;
+
+    dt.fighter = setup_fighter(&b, du);
+    calculate_armor(dt, 0, 0, &magres);
+    CuAssertDblEquals_Msg(tc, "magres unmodified", 0.0, magres, 0.01);
+
+    magres = 1.0;
+    calculate_armor(dt, 0, 0, &magres);
+    CuAssertDblEquals_Msg(tc, "no magres bonus", 0.0, magic_resistance(du), 0.01);
+    CuAssertDblEquals_Msg(tc, "no magres bonus", 1.0, magres, 0.01);
+
+    ashield->flags |= ATF_LAEN;
+    ashield->magres = 0.1;
+    magres = 1.0;
+    calculate_armor(dt, 0, 0, &magres);
+    free_battle(b);
+
+    i_change(&du->items, ishield, 1);
+    i_change(&du->items, ichain, 1);
+    achain->flags |= ATF_LAEN;
+    achain->magres = 0.1;
+    ashield->flags |= ATF_LAEN;
+    ashield->magres = 0.1;
+    dt.fighter = setup_fighter(&b, du);
+    magres = 1.0;
+    calculate_armor(dt, 0, 0, &magres);
+    CuAssertDblEquals_Msg(tc, "laen bonus", 0.81, magres, 0.01);
+    free_battle(b);
+
+    i_change(&du->items, ishield, -1);
+    i_change(&du->items, ichain, -1);
+    set_level(du, SK_MAGIC, 2);
+    dt.fighter = setup_fighter(&b, du);
+    magres = 1.0;
+    calculate_armor(dt, 0, 0, &magres);
+    CuAssertDblEquals_Msg(tc, "magic bonus", 0.1, magic_resistance(du), 0.01);
+    CuAssertDblEquals_Msg(tc, "magic bonus", 0.7, magres, 0.01);
+
+    free_battle(b);
+    test_cleanup();
+}
+
 static void test_projectile_armor(CuTest * tc)
 {
     troop dt;
@@ -321,6 +386,7 @@ CuSuite *get_battle_suite(void)
     SUITE_ADD_TEST(suite, test_building_bonus_respects_size);
     SUITE_ADD_TEST(suite, test_building_defence_bonus);
     SUITE_ADD_TEST(suite, test_calculate_armor);
+    SUITE_ADD_TEST(suite, test_magic_resistance);
     SUITE_ADD_TEST(suite, test_projectile_armor);
     return suite;
 }

src/buildno.h

@@ -1,3 +1,3 @@
 #define VERSION_MAJOR 3
 #define VERSION_MINOR 7
-#define VERSION_BUILD 3
+#define VERSION_BUILD 4

src/kernel/race.c

@@ -183,7 +183,7 @@ race *rc_get_or_create(const char *zName)
         rc->recruit_multi = 1.0F;
         rc->regaura = 1.0F;
         rc->speed = 1.0F;
-        rc->battle_flags = BF_CANATTACK;
+        rc->battle_flags = 0;
         if (strchr(zName, ' ') != NULL) {
             log_error("race '%s' has an invalid name. remove spaces\n", zName);
             assert(strchr(zName, ' ') == NULL);

src/kernel/race.h

@@ -231,7 +231,7 @@ extern "C" {
 #define BF_RES_CUT      (1<<3)  /* Halber Schaden durch CUT */
 #define BF_RES_BASH     (1<<4)  /* Halber Schaden durch BASH */
 #define BF_INV_NONMAGIC (1<<5)  /* Immun gegen nichtmagischen Schaden */
-#define BF_CANATTACK    (1<<6)  /* Kann keine ATTACKIERE Befehle ausfuehren */
+#define BF_NO_ATTACK    (1<<6)  /* Kann keine ATTACKIERE Befehle ausfuehren */
 
     extern int unit_old_max_hp(struct unit *u);
     extern const char *racename(const struct locale *lang, const struct unit *u,

src/kernel/race.test.c

@@ -36,6 +36,7 @@ static void test_rc_defaults(CuTest *tc) {
     CuAssertIntEquals(tc, 0, rc->armor);
     CuAssertIntEquals(tc, 0, rc->at_bonus);
     CuAssertIntEquals(tc, 0, rc->df_bonus);
+    CuAssertIntEquals(tc, 0, rc->battle_flags);
     CuAssertIntEquals(tc, PERSON_WEIGHT, rc->weight);
     test_cleanup();
 }

src/kernel/xmlreader.c

@@ -1721,7 +1721,7 @@ static int parse_races(xmlDocPtr doc)
             rc->ec_flags |= ECF_REC_UNLIMITED;
 
         if (xml_bvalue(node, "equipment", false))
-            rc->battle_flags |= BF_EQUIPMENT;
+            rc->battle_flags |= BF_EQUIPMENT; // TODO: invert this flag, so rc_get_or_create gets simpler
         if (xml_bvalue(node, "noblock", false))
             rc->battle_flags |= BF_NOBLOCK;
         if (xml_bvalue(node, "invinciblenonmagic", false))
@@ -1732,8 +1732,8 @@ static int parse_races(xmlDocPtr doc)
             rc->battle_flags |= BF_RES_CUT;
         if (xml_bvalue(node, "resistpierce", false))
             rc->battle_flags |= BF_RES_PIERCE;
-        if (xml_bvalue(node, "canattack", true))
+        if (xml_bvalue(node, "noattack", false))
-            rc->battle_flags |= BF_CANATTACK; // TODO: invert this flag, so rc_get_or_create gets simpler
+            rc->battle_flags |= BF_NO_ATTACK;
 
         for (child = node->children; child; child = child->next) {
             if (strcmp((const char *)child->name, "ai") == 0) {

src/tests.c

@@ -36,6 +36,7 @@ struct race *test_create_race(const char *name)
     race *rc = rc_get_or_create(name);
     rc->maintenance = 10;
     rc->ec_flags |= GETITEM;
+    rc->battle_flags = BF_EQUIPMENT;
     return rc;
 }