Try to avoid repeats when acquiring already seen weapons/armour.

Weapons: both type and brand is handled, separately.  This means,
    once you've seen any lajatang, there is no more any bonus to
    get them -- you'll get 5 times as many quarterstaves, brand
    repeat protection comes only within the type.

Armour: currently only brand is handled, type will have to be merged
    with the old code which suffered from no information about stash.

3 files changed, 37 insertions, 0 deletions

diff --git a/crawl-ref/source/effects.cc b/crawl-ref/source/effects.cc
index 63730af531..f67d52ca47 100644
--- a/crawl-ref/source/effects.cc
+++ b/crawl-ref/source/effects.cc
@@ -1423,6 +1423,9 @@ static int _acquirement_weapon_subtype()
         else
             acqweight = acqweight * want_shield / dont_shield;
 
+        if (!you.seen_weapon[i])
+            acqweight *= 5; // strong emphasis on type variety, brands go only second
+
         int wskill = range_skill(OBJ_WEAPONS, i);
         if (wskill == SK_THROWING)
             wskill = weapon_skill(OBJ_WEAPONS, i);
@@ -2023,6 +2026,18 @@ int acquirement_create_item(object_class_type class_wanted,
 
         item_def &doodad(mitm[thing_created]);
 
+        // Try to not generate brands that were already seen, although unlike
+        // jewelry and books, this is not absolute.
+        while (!is_artefact(doodad)
+               && (doodad.base_type == OBJ_WEAPONS
+                     && you.seen_weapon[doodad.sub_type] & (1<<get_weapon_brand(doodad))
+                   || doodad.base_type == OBJ_ARMOUR
+                     && you.seen_armour[doodad.sub_type] & (1<<get_weapon_brand(doodad)))
+               && !one_chance_in(5))
+        {
+            reroll_brand(doodad, MAKE_GOOD_ITEM);
+        }
+
         // For plain armour, try to change the subtype to something
         // matching a currently unfilled equipment slot.
         if (doodad.base_type == OBJ_ARMOUR && !is_artefact(doodad))
diff --git a/crawl-ref/source/makeitem.cc b/crawl-ref/source/makeitem.cc
index bfa26805b1..2312bc5712 100644
--- a/crawl-ref/source/makeitem.cc
+++ b/crawl-ref/source/makeitem.cc
@@ -3293,6 +3293,27 @@ int items(int allow_uniques,       // not just true-false,
     return (p);
 }
 
+void reroll_brand(item_def &item, int item_level)
+{
+    ASSERT(!is_artefact(item));
+    switch(item.base_type)
+    {
+    case OBJ_WEAPONS:
+        item.special = _determine_weapon_brand(item, item_level);
+        break;
+    case OBJ_MISSILES:
+        item.special = _determine_missile_brand(item, item_level);
+        break;
+    case OBJ_ARMOUR:
+        // Robe of the Archmagi has an ugly hack of unknown purpose,
+        // as one of side effects it won't ever generate here.
+        item.special = _determine_armour_ego(item, OBJ_ARMOUR, item_level);
+        break;
+    default:
+        ASSERT(!"can't reroll brands of this type");
+    }
+}
+
 static int _roll_rod_enchant(int item_level)
 {
     int value = 0;
diff --git a/crawl-ref/source/makeitem.h b/crawl-ref/source/makeitem.h
index 8e16989c15..7e2d0091ba 100644
--- a/crawl-ref/source/makeitem.h
+++ b/crawl-ref/source/makeitem.h
@@ -37,6 +37,7 @@ bool is_armour_brand_ok(int type, int brand);
 bool is_missile_brand_ok(int type, int brand);
 
 bool got_curare_roll(const int item_level);
+void reroll_brand(item_def &item, int item_level);
 
 #if DEBUG_DIAGNOSTICS || DEBUG_TESTS
 void makeitem_tests();