Fix false draw case.

internal/game/regression_test.go

@@ -24,3 +24,25 @@ func TestCrocodileLastPetVolleyFiresWhenOwnerOut(t *testing.T) {
 		t.Fatalf("both sides should be out (draw), got winner %d", res.WinnerSeat)
 	}
 }
+
+// Regression: a pair that can't hurt each other (two 0-attack pets, here
+// Spooked down to nothing) must both faint so the pets behind them settle the
+// battle. Previously the stalemate ended the whole battle in a draw, even with
+// most of both decks still to come.
+func TestStalematedPairFaintsAndBattleContinues(t *testing.T) {
+	g, p1, _ := unicornGame(t)
+	p1.Mana = 2
+	res := forceBattle(t, g,
+		// Nightcrawler (1 power) Spooks Barghest twice; Barghest (1 power)
+		// Spooks it once. Neither can deal damage, but Pengobble is next up.
+		[]Card{g.unicornPet(t, "Nightcrawler"), g.unicornPet(t, "Pengobble")},
+		[]Card{g.unicornPet(t, "Barghest"), g.pet("Chaff", 1)},
+	)
+	clashes := eventsOfType(res, "clash")
+	if len(clashes) != 1 || !clashes[0].Died[0] || !clashes[0].Died[1] {
+		t.Fatalf("the stuck pair should both faint in one clash: %+v", clashes)
+	}
+	if res.WinnerSeat != 0 {
+		t.Fatalf("Pengobble should go on to win for seat 0, got winner %d", res.WinnerSeat)
+	}
+}