MapWithAILayer: Don't allow MapWithAI data to be merged into a OSM da…

…ta layer.

Signed-off-by: Taylor Smock <[email protected]>

src/main/java/org/openstreetmap/josm/plugins/mapwithai/backend/MapWithAILayer.java

@@ -6,6 +6,8 @@
 import java.awt.Component;
 import java.awt.event.ActionEvent;
 import java.io.File;
+import java.io.IOException;
+import java.nio.file.Files;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collection;
@@ -299,4 +301,16 @@ public Component createMenuComponent() {
         }
 
     }
+
+    @Override
+    public boolean autosave(File file) throws IOException {
+        // Consider a deletion a "successful" save.
+        return Files.deleteIfExists(file.toPath());
+    }
+
+    @Override
+    public boolean isMergable(final Layer other) {
+        // Don't allow this layer to be merged down
+        return other instanceof MapWithAILayer;
+    }
 }