Properly handle negative count RemoveItem (bug #6895)

CHANGELOG.md

@@ -132,6 +132,7 @@
     Bug #6794: Light sources are attached to mesh bounds centers instead of mesh origins when AttachLight NiNode is missing
     Bug #6799: Game crashes if an NPC has no Class attached
     Bug #6849: ImageButton texture is not scaled properly
+    Bug #6895: Removing a negative number of items from a script, makes the script terminate with an error
     Feature #890: OpenMW-CS: Column filtering
     Feature #1465: "Reset" argument for AI functions
     Feature #2491: Ability to make OpenMW "portable"

apps/openmw/mwscript/containerextensions.cpp

@@ -216,7 +216,7 @@ namespace MWScript
                     runtime.pop();
 
                     if (count<0)
-                        throw std::runtime_error ("second argument for RemoveItem must be non-negative");
+                        count = static_cast<uint16_t>(count);
 
                     // no-op
                     if (count == 0)