Make PageImages default API license parameter configurable

Bug: T156190
Change-Id: Id4b43f2597d5a063dca0d46f308b6283620e9974

extension.json

@@ -88,6 +88,10 @@
 			"@doc": "Temporary feature flag - Whether page images should be restricted to those in section id 0.",
 			"@fixme": "Please remove a month after it has defaulted to true on the cluster (T152115)",
 			"value": true
+		},
+		"PageImagesAPIDefaultLicense": {
+			"@doc": "Get images with either a 'free' license or 'any' (including free and non-free) license by default, via 'pilicense' option, in pageprops query api. The value of this setting should be either 'free' or 'any'.",
+			"value": "free"
 		}
 	},
 	"manifest_version": 2

includes/ApiQueryPageImages.php

@@ -264,7 +264,7 @@ class ApiQueryPageImages extends ApiQueryBase {
 			'license' => [
 				ApiBase::PARAM_TYPE => [ self::PARAM_LICENSE_FREE, self::PARAM_LICENSE_ANY ],
 				ApiBase::PARAM_ISMULTI => false,
-				ApiBase::PARAM_DFLT => self::PARAM_LICENSE_FREE,
+				ApiBase::PARAM_DFLT => $this->getConfig()->get( 'PageImagesAPIDefaultLicense' ),
 			],
 			'continue' => [
 				ApiBase::PARAM_TYPE => 'integer',

tests/phpunit/ApiQueryPageImagesTest.php

@@ -59,10 +59,18 @@ class ApiQueryPageImagesProxy extends ApiQueryPageImages {
 class ApiQueryPageImagesTest extends PHPUnit_Framework_TestCase {
 
 	private function newInstance() {
+		$config = new \HashConfig( [
+			'PageImagesAPIDefaultLicense' => 'free'
+		]);
+
 		$context = $this->getMockBuilder( 'IContextSource' )
 			->disableOriginalConstructor()
 			->getMock();
 
+		$context->expects( $this->any() )
+			->method( 'getConfig' )
+			->willReturn( $config );
+
 		$main = $this->getMockBuilder( 'ApiMain' )
 			->disableOriginalConstructor()
 			->getMock();