Fix relation caching

src/Model.php

@@ -1100,7 +1100,7 @@ protected function save_has_foreign_relations() {
 	protected function save_loaded_relations( array $exclude = array() ) {
 		foreach ( $this->_relations as $relation => $values ) {
 
-			if ( in_array( $relation, $exclude ) ) {
+			if ( in_array( $relation, $exclude ) || $values === null ) {
 				continue;
 			}
 

src/Relations/HasForeign.php

@@ -145,10 +145,13 @@ public function eager_load( array $models, $callback = null ) {
 		$related_models = $this->fetch_results_for_eager_load( $pks );
 
 		foreach ( $related_models as $related_model ) {
-			if ( ! empty( $map[ $this->saver->get_pk( $related_model ) ] ) ) {
-				foreach ( $map[ $this->saver->get_pk( $related_model ) ] as $mapped ) {
+			$pk = $this->saver->get_pk( $related_model );
+
+			if ( ! empty( $map[ $pk ] ) ) {
+				foreach ( $map[ $pk ] as $mapped ) {
 					$mapped->set_raw_attribute( $this->attribute, $related_model );
 					$mapped->sync_original_attribute( $this->attribute );
+					$this->cache_results( $this->saver->get_model( $pk ), $mapped );
 				}
 			}
 		}

src/Relations/HasOneOrMany.php

@@ -196,10 +196,13 @@ public function eager_load( array $models, $callback = null ) {
 			if ( isset( $map[ $model->get_pk() ] ) ) {
 				$related = $map[ $model->get_pk() ];
 
-				$model->set_relation_value( $this->attribute, $this->wrap_eager_loaded_results( $related ) );
+				$result = $this->wrap_eager_loaded_results( $related );
 			} else {
-				$model->set_relation_value( $this->attribute, $this->wrap_eager_loaded_results( null ) );
+				$result = $this->wrap_eager_loaded_results( null );
 			}
+
+			$model->set_relation_value( $this->attribute, $result );
+			$this->cache_results( $result, $model );
 		}
 
 		return $results;
@@ -215,4 +218,4 @@ public function eager_load( array $models, $callback = null ) {
 	 * @return mixed
 	 */
 	protected abstract function wrap_eager_loaded_results( $results );
-}
+}

src/Relations/ManyToMany.php

@@ -348,7 +348,8 @@ public function eager_load( array $models, $callback = null ) {
 
 		foreach ( $models as $model ) {
 			$data = isset( $relationship_map[ $model->get_pk() ] ) ? $relationship_map[ $model->get_pk() ] : array();
-			$model->set_relation_value( $attribute, new Collection( $data, $memory, $this->saver ) );
+			$model->set_relation_value( $attribute, $value = new Collection( $data, $memory, $this->saver ) );
+			$this->cache_results( $value, $model );
 		}
 
 		return new Collection( $related, true, $this->saver );
@@ -366,6 +367,7 @@ public function persist( $values ) {
 		$added = $this->persist_do_save( $values );
 
 		$this->persist_added( new ArrayCollection( $values->get_added()->toArray() + $added ) );
+		$values->clear_memory();
 
 		return $values;
 	}
@@ -496,4 +498,4 @@ public function on_delete( Model $model ) {
 			$this->other_column => $model->get_pk()
 		) );
 	}
-}
+}

src/Relations/ManyToManyUsers.php

@@ -116,4 +116,4 @@ public function eager_load( array $models, $callback = null ) {
 
 		return $loaded;
 	}
-}
+}