Fall back to the map name if no player alias is set

The behaviour of these function is back to their 1.12.2 behaviour, as they will no longer return `null` values for maps
that have no player alias set:
- `getMapDisplayName()`
- `getAllMapDisplayNames()`
- `getVisibleMapDisplayNames()`

Also `getMapName()` will once again be able to find maps by matching the name when no player alias is set.

The new method `Zone.getDisplayName()` can be used to get the name of the zone to show to players, whether that is the
player alias or the regular name.

src/main/java/net/rptools/maptool/client/functions/MapFunctions.java

@@ -70,7 +70,7 @@ public Object childEvaluate(
       FunctionUtil.blockUntrustedMacro(functionName);
       FunctionUtil.checkNumberParam(functionName, parameters, 0, 1);
       final var zr = FunctionUtil.getZoneRendererFromParam(functionName, parameters, 0);
-      return zr.getZone().getPlayerAlias();
+      return zr.getZone().getDisplayName();
 
     } else if (functionName.equalsIgnoreCase("setCurrentMap")) {
       FunctionUtil.blockUntrustedMacro(functionName);
@@ -116,21 +116,25 @@ public Object childEvaluate(
       FunctionUtil.checkNumberParam(functionName, parameters, 2, 2);
       String mapName = parameters.get(0).toString();
       String newMapDisplayName = parameters.get(1).toString();
+
       Zone zone = FunctionUtil.getZoneRenderer(functionName, mapName).getZone();
-      String oldName = zone.getPlayerAlias();
-      zone.setPlayerAlias(newMapDisplayName);
-      if (oldName.equals(newMapDisplayName)) {
-        return zone.getPlayerAlias();
+      if (newMapDisplayName.equals(zone.getDisplayName())) {
+        // The name is the same, so nothing to do.
+        return newMapDisplayName;
+      }
+
+      final var nameChangeAccepted = zone.setPlayerAlias(newMapDisplayName);
+      if (!nameChangeAccepted) {
+        throw new ParserException(
+            I18N.getText("macro.function.map.duplicateDisplay", functionName));
       }
+
       MapTool.serverCommand().changeZoneDispName(zone.getId(), newMapDisplayName);
       if (zone == MapTool.getFrame().getCurrentZoneRenderer().getZone()) {
         MapTool.getFrame().setCurrentZoneRenderer(MapTool.getFrame().getCurrentZoneRenderer());
       }
-      if (oldName.equals(zone.getPlayerAlias())) {
-        throw new ParserException(
-            I18N.getText("macro.function.map.duplicateDisplay", functionName));
-      }
-      return zone.getPlayerAlias();
+
+      return zone.getDisplayName();
 
     } else if ("copyMap".equalsIgnoreCase(functionName)) {
       FunctionUtil.blockUntrustedMacro(functionName);
@@ -175,7 +179,7 @@ public Object childEvaluate(
       List<String> mapNames = new LinkedList<>();
       for (ZoneRenderer zr : MapTool.getFrame().getZoneRenderers()) {
         if (allMaps || zr.getZone().isVisible()) {
-          mapNames.add(zr.getZone().getPlayerAlias());
+          mapNames.add(zr.getZone().getDisplayName());
         }
       }
 
@@ -188,7 +192,7 @@ public Object childEvaluate(
       FunctionUtil.blockUntrustedMacro(functionName);
 
       for (ZoneRenderer zr : MapTool.getFrame().getZoneRenderers()) {
-        if (zr.getZone().getPlayerAlias().equals(displayName)) {
+        if (displayName.equals(zr.getZone().getDisplayName())) {
           return zr.getZone().getName();
         }
       }

src/main/java/net/rptools/maptool/client/functions/getInfoFunction.java

@@ -123,7 +123,7 @@ private JsonObject getMapInfo() throws ParserException {
     }
 
     minfo.addProperty("name", zone.getName());
-    minfo.addProperty("display name", zone.getPlayerAlias());
+    minfo.addProperty("display name", zone.getDisplayName());
     minfo.addProperty("image x scale", zone.getImageScaleX());
     minfo.addProperty("image y scale", zone.getImageScaleY());
     minfo.addProperty("player visible", zone.isVisible() ? 1 : 0);

src/main/java/net/rptools/maptool/client/ui/zone/ZoneRenderer.java

@@ -1985,7 +1985,7 @@ public boolean isLoading() {
     loadingProgress =
         String.format(
             " Loading Map '%s' - %d/%d Loaded %d/%d Cached",
-            zone.getPlayerAlias(), downloadCount, assetSet.size(), cacheCount, assetSet.size());
+            zone.getDisplayName(), downloadCount, assetSet.size(), cacheCount, assetSet.size());
     isLoaded = loaded;
     if (isLoaded) {
       // Notify the token tree that it should update

src/main/java/net/rptools/maptool/model/Zone.java

@@ -22,6 +22,7 @@
 import java.util.*;
 import java.util.stream.Collectors;
 import javax.annotation.Nonnull;
+import javax.annotation.Nullable;
 import net.rptools.lib.MD5Key;
 import net.rptools.maptool.client.AppPreferences;
 import net.rptools.maptool.client.AppUtil;
@@ -368,14 +369,27 @@ public void setFogPaint(DrawablePaint paint) {
   }
 
   /** @return name of the zone */
-  public String getName() {
+  public @Nonnull String getName() {
     return name;
   }
 
-  public String getPlayerAlias() {
+  /** @return The zone's player alias, if set. Otherwise {@code null}. */
+  public @Nullable String getPlayerAlias() {
     return playerAlias;
   }
 
+  /**
+   * Get the name of the map to show to players.
+   *
+   * <p>If a player alias is set, that will be used as the display name. Otherwise the name is used
+   * as the display name.
+   *
+   * @return The name of the map that should be shown to players.
+   */
+  public @Nonnull String getDisplayName() {
+    return Objects.requireNonNullElse(playerAlias, name);
+  }
+
   public void setName(String name) {
     this.name = name;
   }
@@ -399,7 +413,7 @@ public boolean setPlayerAlias(String playerAlias) {
   @Override
   public String toString() {
     if (!MapTool.getPlayer().isGM()) {
-      return playerAlias != null ? playerAlias : name;
+      return getDisplayName();
     } else if (playerAlias == null || name.equals(playerAlias)) {
       return name;
     } else {
@@ -2051,6 +2065,12 @@ private void collapseDrawableLayer(List<DrawnElement> layer) {
   ////
   // Backward compatibility
   protected Object readResolve() {
+    if ("".equals(playerAlias) || name.equals(playerAlias)) {
+      // Don't keep redundant player aliases around. The display name will default to the name if
+      // no player alias is set.
+      playerAlias = null;
+    }
+
     // 1.3b76 -> 1.3b77
     // adding the exposed area for Individual FOW
     if (exposedAreaMeta == null) {