From 0d4c71f393a9d73981b9cf25287e3213ffddeb1a Mon Sep 17 00:00:00 2001
From: Damian Mooyman <damian@silverstripe.com>
Date: Mon, 2 May 2016 16:41:30 +1200
Subject: [PATCH] API Filtering on invalid relation is no longer a silent error
 Fixes #5331

---
 model/DataList.php           |  2 +-
 model/DataQuery.php          | 14 ++++++++++----
 tests/model/DataListTest.php | 11 +++++++++++
 3 files changed, 22 insertions(+), 5 deletions(-)

diff --git a/model/DataList.php b/model/DataList.php
index 7fc8d6549..d4072437f 100644
--- a/model/DataList.php
+++ b/model/DataList.php
@@ -503,7 +503,7 @@ class DataList extends ViewableData implements SS_List, SS_Filterable, SS_Sortab
 				$fieldName = array_pop($relations);
 
 				// Apply
-				$relationModelName = $query->applyRelation($field, $linearOnly);
+				$relationModelName = $query->applyRelation($relations, $linearOnly);
 
 				// Find the db field the relation belongs to
 				$className = ClassInfo::table_for_object_field($relationModelName, $fieldName);
diff --git a/model/DataQuery.php b/model/DataQuery.php
index 77913baeb..f3b14294c 100644
--- a/model/DataQuery.php
+++ b/model/DataQuery.php
@@ -641,16 +641,20 @@ class DataQuery {
 	 * mappings to the query object state. This has to be called
 	 * in any overloaded {@link SearchFilter->apply()} methods manually.
 	 *
-	 * @param String|array $relation The array/dot-syntax relation to follow
+	 * @param string|array $relation The array/dot-syntax relation to follow
 	 * @param bool $linearOnly Set to true to restrict to linear relations only. Set this
 	 * if this relation will be used for sorting, and should not include duplicate rows.
-	 * @return The model class of the related item
+	 * @return string The model class of the related item
 	 */
 	public function applyRelation($relation, $linearOnly = false) {
 		// NO-OP
-		if(!$relation) return $this->dataClass;
+		if(!$relation) {
+			return $this->dataClass;
+		}
 
-		if(is_string($relation)) $relation = explode(".", $relation);
+		if(is_string($relation)) {
+			$relation = explode(".", $relation);
+		}
 
 		$modelClass = $this->dataClass;
 
@@ -682,6 +686,8 @@ class DataQuery {
 				);
 				$modelClass = $componentClass;
 
+			} else {
+				throw new InvalidArgumentException("$rel is not a relation on model $modelClass");
 			}
 		}
 
diff --git a/tests/model/DataListTest.php b/tests/model/DataListTest.php
index dcf709f05..a0d84f4ae 100755
--- a/tests/model/DataListTest.php
+++ b/tests/model/DataListTest.php
@@ -833,6 +833,17 @@ class DataListTest extends SapphireTest {
 		$this->assertEquals('007', $list->first()->ShirtNumber);
 	}
 
+	public function testFilterOnInvalidRelation() {
+		$this->setExpectedException(
+			'InvalidArgumentException',
+			"MascotAnimal is not a relation on model DataObjectTest_Team"
+		);
+		// Filter on missing relation 'MascotAnimal'
+		DataObjectTest_Team::get()
+			->filter('MascotAnimal.Name', 'Richard')
+			->toArray();
+	}
+
 	public function testFilterAndExcludeById() {
 		$id = $this->idFromFixture('DataObjectTest_SubTeam', 'subteam1');
 		$list = DataObjectTest_SubTeam::get()->filter('ID', $id);