fix and test Font of Agonies

fixes #13717

Mage.Tests/src/test/java/org/mage/test/cards/single/rna/FontOfAgoniesTest.java

@@ -0,0 +1,53 @@
+package org.mage.test.cards.single.rna;
+
+import mage.constants.PhaseStep;
+import mage.constants.Zone;
+import mage.counters.CounterType;
+import org.junit.Test;
+import org.mage.test.serverside.base.CardTestPlayerBase;
+
+/**
+ * @author Susucr
+ */
+public class FontOfAgoniesTest extends CardTestPlayerBase {
+
+    /**
+     * {@link mage.cards.f.FontOfAgonies Font of Agonies} {B}
+     * Enchantment
+     * Whenever you pay life, put that many blood counters on this enchantment.
+     * {1}{B}, Remove four blood counters from this enchantment: Destroy target creature.
+     */
+    private static final String font = "Font of Agonies";
+
+    @Test
+    public void test_Fetchland() {
+        addCard(Zone.BATTLEFIELD, playerA, font, 1);
+        addCard(Zone.BATTLEFIELD, playerA, "Arid Mesa", 1);
+
+        activateAbility(1, PhaseStep.PRECOMBAT_MAIN, playerA, "{T}");
+        addTarget(playerA, "Mountain");
+
+        setStrictChooseMode(true);
+        setStopAt(1, PhaseStep.POSTCOMBAT_MAIN);
+        execute();
+
+        assertLife(playerA, 20 - 1);
+        assertCounterCount(playerA, font, CounterType.BLOOD, 1);
+    }
+
+    @Test
+    public void test_Pay2() {
+        addCard(Zone.BATTLEFIELD, playerA, font, 1);
+        addCard(Zone.BATTLEFIELD, playerA, "Book of Rass", 1); // {2}, Pay 2 life: Draw a card.
+        addCard(Zone.BATTLEFIELD, playerA, "Plains", 2);
+
+        activateAbility(1, PhaseStep.PRECOMBAT_MAIN, playerA, "{2}");
+
+        setStrictChooseMode(true);
+        setStopAt(1, PhaseStep.POSTCOMBAT_MAIN);
+        execute();
+
+        assertLife(playerA, 20 - 2);
+        assertCounterCount(playerA, font, CounterType.BLOOD, 2);
+    }
+}

Mage/src/main/java/mage/util/CardUtil.java

@@ -1774,8 +1774,9 @@ public final class CardUtil {
             // Waiting on actual ruling of Ashiok, Wicked Manipulator.
             return true;
         }
-        if (player.loseLife(lifeToPay, game, source, false) >= lifeToPay) {
+        int lostLife = player.loseLife(lifeToPay, game, source, false);
-            game.fireEvent(GameEvent.getEvent(GameEvent.EventType.LIFE_PAID, player.getId(), source, player.getId(), lifeToPay));
+        if (lostLife > 0) {
+            game.fireEvent(GameEvent.getEvent(GameEvent.EventType.LIFE_PAID, player.getId(), source, player.getId(), lostLife));
             return true;
         }