From 3044bf2e2313bd5a679b9dbd31a6768ac68400f3 Mon Sep 17 00:00:00 2001
From: Grath <1895280+Grath@users.noreply.github.com>
Date: Fri, 27 Jan 2023 22:10:03 -0500
Subject: [PATCH] Fix Twinning Staff to only happen when one or more copies
 would be made, and not zero. (#9843)

* Fix Twinning Staff to only apply when you're copying the spell at least one time.

* Fix test so it works
---
 Mage.Sets/src/mage/cards/t/TwinningStaff.java   |  3 ++-
 .../cards/single/c20/TwinningStaffTest.java     | 17 +++++++++++++++++
 2 files changed, 19 insertions(+), 1 deletion(-)

diff --git a/Mage.Sets/src/mage/cards/t/TwinningStaff.java b/Mage.Sets/src/mage/cards/t/TwinningStaff.java
index 75ccd4506d..718392a8b0 100644
--- a/Mage.Sets/src/mage/cards/t/TwinningStaff.java
+++ b/Mage.Sets/src/mage/cards/t/TwinningStaff.java
@@ -82,7 +82,8 @@ class TwinningStaffEffect extends ReplacementEffectImpl {
     @Override
     public boolean applies(GameEvent event, Ability source, Game game) {
         return event.getPlayerId().equals(source.getControllerId())
-                && game.getSpellOrLKIStack(event.getTargetId()) != null;
+                && game.getSpellOrLKIStack(event.getTargetId()) != null
+                && event.getAmount() >= 1;
     }
 
     @Override
diff --git a/Mage.Tests/src/test/java/org/mage/test/cards/single/c20/TwinningStaffTest.java b/Mage.Tests/src/test/java/org/mage/test/cards/single/c20/TwinningStaffTest.java
index 7d4b1a1d06..a03aeb2ad5 100644
--- a/Mage.Tests/src/test/java/org/mage/test/cards/single/c20/TwinningStaffTest.java
+++ b/Mage.Tests/src/test/java/org/mage/test/cards/single/c20/TwinningStaffTest.java
@@ -85,4 +85,21 @@ public class TwinningStaffTest extends CardTestPlayerBase {
         assertGraveyardCount(playerA, bear, 1);
         assertGraveyardCount(playerA, elite, 1);
     }
+
+    @Test
+    public void testThousandYearStormZeroCopies() {
+        addCard(Zone.BATTLEFIELD, playerA, "Badlands", 2);
+        addCard(Zone.BATTLEFIELD, playerA, "Thousand-Year Storm");
+        addCard(Zone.BATTLEFIELD, playerA, staff);
+        addCard(Zone.HAND, playerA, "Lightning Bolt", 2);
+
+        castSpell(1, PhaseStep.UPKEEP, playerA, "Lightning Bolt", playerB);
+        checkLife("before", 1, PhaseStep.PRECOMBAT_MAIN, playerB, 20 - 3);
+
+        castSpell(1, PhaseStep.PRECOMBAT_MAIN, playerA, "Lightning Bolt", playerB);
+        setStrictChooseMode(false);
+        checkLife("copy", 1, PhaseStep.END_COMBAT, playerB, 20 - 3 - 3 * 3);
+        setStopAt(1, PhaseStep.END_TURN);
+        execute();
+    }
 }