Don't offer a price of 1 gold for zero value items (#5484)

CHANGELOG.md

@@ -29,6 +29,7 @@
     Bug #5441: Enemies can't push a player character when in critical strike stance
     Bug #5451: Magic projectiles don't disappear with the caster
     Bug #5452: Autowalk is being included in savegames
+    Bug #5484: Zero value items shouldn't be able to be bought or sold for 1 gold
     Feature #390: 3rd person look "over the shoulder"
     Feature #2386: Distant Statics in the form of Object Paging
     Feature #5297: Add a search function to the "Datafiles" tab of the OpenMW launcher

apps/openmw/mwmechanics/mechanicsmanagerimp.cpp

@@ -679,7 +679,9 @@ namespace MWMechanics
 
     int MechanicsManager::getBarterOffer(const MWWorld::Ptr& ptr,int basePrice, bool buying)
     {
-        if (ptr.getTypeName() == typeid(ESM::Creature).name())
+        // Make sure zero base price items/services can't be bought/sold for 1 gold
+        // and return the intended base price for creature merchants
+        if (basePrice == 0 || ptr.getTypeName() == typeid(ESM::Creature).name())
             return basePrice;
 
         const MWMechanics::NpcStats &sellerStats = ptr.getClass().getNpcStats(ptr);