Don't stack used torches

apps/openmw/mwworld/class.cpp

@@ -139,7 +139,7 @@ namespace MWWorld
 
     float Class::getRemainingUsageTime (const Ptr& ptr) const
     {
-        throw std::runtime_error ("class does not support time-based uses");
+        return -1;
     }
 
     std::string Class::getScript (const Ptr& ptr) const

apps/openmw/mwworld/class.hpp

@@ -162,7 +162,7 @@ namespace MWWorld
 
             virtual float getRemainingUsageTime (const Ptr& ptr) const;
             ///< Returns the remaining duration of the object, such as an equippable light
-            /// source. (default implementation: throw an exception)
+            /// source. (default implementation: -1, i.e. infinite)
 
             virtual std::string getScript (const Ptr& ptr) const;
             ///< Return name of the script attached to ptr (default implementation: return an empty

apps/openmw/mwworld/containerstore.cpp

@@ -109,6 +109,8 @@ bool MWWorld::ContainerStore::stacks(const Ptr& ptr1, const Ptr& ptr2)
         && ptr1.getCellRef().mOwner == ptr2.getCellRef().mOwner
         && ptr1.getCellRef().mSoul == ptr2.getCellRef().mSoul
 
+        && ptr1.getClass().getRemainingUsageTime(ptr1) == ptr2.getClass().getRemainingUsageTime(ptr2)
+
         && cls1.getScript(ptr1) == cls2.getScript(ptr2)
 
         // item that is already partly used up never stacks