fix isEmpty method for file validator.

framework/validators/FileValidator.php

@@ -229,7 +229,9 @@ class FileValidator extends Validator
 	 */
 	public function isEmpty($value, $trim = false)
 	{
-		return !$value instanceof UploadedFile || $value->error == UPLOAD_ERR_NO_FILE;
+        $value = is_array($value) && !empty($value) ? $value[0] : $value;
+
+        return !$value instanceof UploadedFile || $value->error == UPLOAD_ERR_NO_FILE;
 	}
 
 	/**

tests/unit/data/validators/models/FakedValidationModel.php

@@ -30,6 +30,8 @@ class FakedValidationModel extends Model
 		return [
 			[['val_attr_a', 'val_attr_b'], 'required', 'on' => 'reqTest'],
 			['val_attr_c', 'integer'],
+            ['attr_images', 'file', 'maxFiles' => 3, 'types' => ['png'], 'on' => 'validateMultipleFiles'],
+            ['attr_image', 'file', 'types' => ['png'], 'on' => 'validateFile']
 		];
 	}
 

tests/unit/framework/validators/FileValidatorTest.php

@@ -107,6 +107,68 @@ class FileValidatorTest extends TestCase
 		$val->validateAttribute($m, 'attr_files');
 		$this->assertTrue($m->hasErrors());
 		$this->assertTrue(stripos(current($m->getErrors('attr_files')), 'you can upload at most') !== false);
+
+        $m = FakedValidationModel::createWithAttributes(
+            [
+                'attr_images' => $this->createTestFiles(
+                        [
+                            [
+                                'name' => 'image.png',
+                                'size' => 1024,
+                                'type' => 'image/png'
+                            ],
+                            [
+                                'name' => 'image.png',
+                                'size' => 1024,
+                                'type' => 'image/png'
+                            ],
+                            [
+                                'name' => 'text.txt',
+                                'size' => 1024
+                            ],
+                        ]
+                    )
+            ]
+        );
+        $m->setScenario('validateMultipleFiles');
+        $this->assertFalse($m->validate());
+        $this->assertTrue(stripos(current($m->getErrors('attr_images')), 'Only files with these extensions are allowed') !== false);
+
+        $m = FakedValidationModel::createWithAttributes(
+            [
+                'attr_images' => $this->createTestFiles(
+                        [
+                            [
+                                'name' => 'image.png',
+                                'size' => 1024,
+                                'type' => 'image/png'
+                            ],
+                            [
+                                'name' => 'image.png',
+                                'size' => 1024,
+                                'type' => 'image/png'
+                            ],
+                        ]
+                    )
+            ]
+        );
+        $m->setScenario('validateMultipleFiles');
+        $this->assertTrue($m->validate());
+
+        $m = FakedValidationModel::createWithAttributes(
+            [
+                'attr_image' => $this->createTestFiles(
+                        [
+                            [
+                                'name' => 'text.txt',
+                                'size' => 1024,
+                            ],
+                        ]
+                    )
+            ]
+        );
+        $m->setScenario('validateFile');
+        $this->assertFalse($m->validate());
 	}
 
 	/**