Improve can't win/lose effects for multiplayer

Fixes: core-developers/forge#170

Signed-off-by: Jamin W. Collins <jamin.collins@gmail.com>

forge-game/src/main/java/forge/game/GameAction.java

@@ -1206,6 +1206,7 @@ public class GameAction {
     public void checkGameOverCondition() {
         // award loses as SBE
         List<Player> losers = null;
+
         FCollectionView<Player> allPlayers = game.getPlayers();
         for (Player p : allPlayers) {
             if (p.checkLoseCondition()) { // this will set appropriate outcomes
@@ -1219,14 +1220,14 @@ public class GameAction {
 
         GameEndReason reason = null;
         // Has anyone won by spelleffect?
-        for (Player p : game.getPlayers()) {
+        for (Player p : allPlayers) {
             if (!p.hasWon()) {
                 continue;
             }
 
             // then the rest have lost!
             reason = GameEndReason.WinsGameSpellEffect;
-            for (Player pl : game.getPlayers()) {
+            for (Player pl : allPlayers) {
                 if (pl.equals(p)) {
                     continue;
                 }
@@ -1243,6 +1244,23 @@ public class GameAction {
             break;
         }
 
+        // loop through all the non-losing players that can't win
+        // see if all of their opponents are in that "about to lose" collection
+        if (losers != null) {
+            for (Player p : allPlayers) {
+                if (losers.contains(p)) {
+                    continue;
+                }
+                if (p.cantWin()) {
+                    if (losers.containsAll(p.getOpponents())) {
+                        // what to do here?!?!?!
+                        System.err.println(p.toString() + " is about to win, but can't!");
+                    }
+                }
+
+            }
+        }
+
         // need a separate loop here, otherwise ConcurrentModificationException is raised
         if (losers != null) {
             for (Player p : losers) {

forge-game/src/main/java/forge/game/player/Player.java

@@ -1825,7 +1825,7 @@ public class Player extends GameEntity implements Comparable<Player> {
         if (getOutcome() != null && getOutcome().lossState == GameLossReason.Conceded) {
             return false;
         }
-        return (hasKeyword("You can't lose the game.") || Iterables.any(getOpponents(), PlayerPredicates.CANT_WIN));
+        return hasKeyword("You can't lose the game.");
     }
 
     public final boolean cantLoseForZeroOrLessLife() {