Fix not clearing user's permissions, and issue with unsetting permissions

common/src/main/java/me/lucko/luckperms/core/PermissionHolder.java

@@ -423,7 +423,7 @@ public abstract class PermissionHolder {
      * @throws ObjectLacksException if the holder doesn't have this node already
      */
     public void unsetPermission(Node node) throws ObjectLacksException {
-        if (hasPermission(node, false) == Tristate.FALSE) {
+        if (hasPermission(node, false) != Tristate.TRUE) {
             throw new ObjectLacksException();
         }
 

common/src/main/java/me/lucko/luckperms/storage/methods/FlatfileDatastore.java

@@ -228,6 +228,13 @@ public class FlatfileDatastore extends Datastore {
     @Override
     public boolean saveUser(User user) {
         File userFile = new File(usersDir, user.getUuid().toString() + ".json");
+        if (!plugin.getUserManager().shouldSave(user)) {
+            if (userFile.exists()) {
+                userFile.delete();
+            }
+            return true;
+        }
+
         if (!userFile.exists()) {
             try {
                 userFile.createNewFile();

common/src/main/java/me/lucko/luckperms/storage/methods/MongoDBDatastore.java

@@ -169,7 +169,11 @@ public class MongoDBDatastore extends Datastore {
     @Override
     public boolean saveUser(User user) {
         if (!plugin.getUserManager().shouldSave(user)) {
-            return true;
+            boolean success = call(() -> {
+                MongoCollection<Document> c = database.getCollection("users");
+                return c.deleteOne(new Document("_id", user.getUuid())).wasAcknowledged();
+            }, false);
+            return success;
         }
 
         boolean success = call(() -> {

common/src/main/java/me/lucko/luckperms/storage/methods/SQLDatastore.java

@@ -55,7 +55,8 @@ abstract class SQLDatastore extends Datastore {
     private static final String USER_SELECT = "SELECT * FROM lp_users WHERE uuid=?";
     private static final String USER_SELECT_ALL = "SELECT uuid FROM lp_users";
     private static final String USER_UPDATE = "UPDATE lp_users SET name=?, primary_group = ?, perms=? WHERE uuid=?";
-    private static final String USER_DELETE = "DELETE FROM lp_users WHERE perms=?";
+    private static final String USER_DELETE = "DELETE FROM lp_users WHERE uuid=?";
+    private static final String USER_DELETE_ALL = "DELETE FROM lp_users WHERE perms=?";
 
     private static final String GROUP_INSERT = "INSERT INTO lp_groups VALUES(?, ?)";
     private static final String GROUP_SELECT = "SELECT perms FROM lp_groups WHERE name=?";
@@ -189,7 +190,13 @@ abstract class SQLDatastore extends Datastore {
     @Override
     public boolean saveUser(User user) {
         if (!plugin.getUserManager().shouldSave(user)) {
-            return true;
+            boolean success = runQuery(new QueryPS(USER_DELETE) {
+                @Override
+                void onRun(PreparedStatement preparedStatement) throws SQLException {
+                    preparedStatement.setString(1, user.getUuid().toString());
+                }
+            });
+            return success;
         }
 
         boolean success = runQuery(new QueryRS(USER_SELECT) {
@@ -234,7 +241,7 @@ abstract class SQLDatastore extends Datastore {
 
     @Override
     public boolean cleanupUsers() {
-        boolean success = runQuery(new QueryPS(USER_DELETE) {
+        boolean success = runQuery(new QueryPS(USER_DELETE_ALL) {
             @Override
             void onRun(PreparedStatement preparedStatement) throws SQLException {
                 preparedStatement.setString(1, "{\"group.default\":true}");

common/src/main/java/me/lucko/luckperms/users/UserManager.java

@@ -61,11 +61,13 @@ public abstract class UserManager extends AbstractManager<UUID, User> {
 
     @Override
     public void copy(User from, User to) {
+        if (from.getPrimaryGroup() != null) {
+            // This isn't just a black user. we shouldn't override in that case.
             to.setNodes(from.getNodes());
             to.setPrimaryGroup(from.getPrimaryGroup());
-        giveDefaultIfNeeded(to, true);
             to.refreshPermissions();
         }
+    }
 
     /**
      * Set a user to the default group