v1.3.0: added some safety checks to prevent stacking artifact/ring buffs

core/src/main/java/com/shatteredpixel/shatteredpixeldungeon/items/artifacts/Artifact.java

@@ -82,6 +82,10 @@ public class Artifact extends KindofMisc {
 	}
 
 	public void activate( Char ch ) {
+		if (passiveBuff != null){
+			passiveBuff.detach();
+			passiveBuff = null;
+		}
 		passiveBuff = passiveBuff();
 		passiveBuff.attachTo(ch);
 	}

core/src/main/java/com/shatteredpixel/shatteredpixeldungeon/items/rings/Ring.java

@@ -113,6 +113,10 @@ public class Ring extends KindofMisc {
 	}
 	
 	public void activate( Char ch ) {
+		if (buff != null){
+			buff.detach();
+			buff = null;
+		}
 		buff = buff();
 		buff.attachTo( ch );
 	}
@@ -121,8 +125,10 @@ public class Ring extends KindofMisc {
 	public boolean doUnequip( Hero hero, boolean collect, boolean single ) {
 		if (super.doUnequip( hero, collect, single )) {
 
-			hero.remove( buff );
-			buff = null;
+			if (buff != null) {
+				buff.detach();
+				buff = null;
+			}
 
 			return true;