General: Make sure get_file_data() recognizes headers prefixed by a <? tag.

This allows for using both of the following single-line headers formats:
{{{
<?php // Template Name: Full-Width ?>
}}}
or with a PHP short open tag:
{{{
<? # Template Name: Full-Width ?>
}}}

Previously, only the first one would be recognized correctly.

Follow-up to [51182], [62802].

Props birgire, gschoppe, sukhendu2002, SergeyBiryukov.
Fixes #42517.

git-svn-id: https://develop.svn.wordpress.org/trunk@62803 602fd350-edb4-49c9-b593-d223f7449a82

Author: SergeyBiryukov

src/wp-includes/functions.php

@@ -7051,7 +7051,7 @@ function get_file_data( $file, $default_headers, $context = '' ) {
 	}
 
 	foreach ( $all_headers as $field => $regex ) {
-		if ( preg_match( '/^(?:[ \t]*<\?php)?[ \t\/*#@]*' . preg_quote( $regex, '/' ) . ':(.*)$/mi', $file_data, $match ) && $match[1] ) {
+		if ( preg_match( '/^(?:[ \t]*<\?(?:php)?)?[ \t\/*#@]*' . preg_quote( $regex, '/' ) . ':(.*)$/mi', $file_data, $match ) && $match[1] ) {
 			$all_headers[ $field ] = _cleanup_header_comment( $match[1] );
 		} else {
 			$all_headers[ $field ] = '';

tests/phpunit/data/formatting/file-header-php-short-open-tag-prefix.php

@@ -0,0 +1 @@
+<? # Template Name: Something ?>

tests/phpunit/tests/functions/getFileData.php

@@ -16,14 +16,15 @@ class Tests_Functions_GetFileData extends WP_UnitTestCase {
 	 * Tests get_file_data().
 	 *
 	 * @ticket 19854
+	 * @ticket 42517
 	 * @ticket 47186
 	 *
 	 * @dataProvider data_test_get_data_file
 	 *
-	 * @param string $file     File path, relative to the test data directory.
-	 * @param array  $headers  Default headers.
-	 * @param string $context  Context.
-	 * @param array  $expected Expected headers.
+	 * @param string                $file     File path, relative to the test data directory.
+	 * @param array<string, string> $headers  Default headers.
+	 * @param string                $context  Context.
+	 * @param array<string, string> $expected Expected headers.
 	 */
 	public function test_get_file_data( $file, $headers, $context, $expected ) {
 		$actual = get_file_data( DIR_TESTDATA . $file, $headers, $context );
@@ -47,7 +48,7 @@ public function test_get_file_data( $file, $headers, $context, $expected ) {
 	 */
 	public function data_test_get_data_file() {
 		return array(
-			'theme headers'       => array(
+			'theme headers'             => array(
 				'file'     => '/themedir1/default/style.css',
 				'headers'  => array(
 					'Name'        => 'Theme Name',
@@ -67,7 +68,7 @@ public function data_test_get_data_file() {
 					'AuthorURI'   => 'http://binarybonsai.com/',
 				),
 			),
-			'cr line endings'     => array(
+			'cr line endings'           => array(
 				'file'     => '/formatting/file-header-cr-line-endings.php',
 				'headers'  => array(
 					'SomeHeader'  => 'Some Header',
@@ -81,7 +82,7 @@ public function data_test_get_data_file() {
 					'Author'      => 'A Very Old Mac',
 				),
 			),
-			'php open tag prefix' => array(
+			'php open tag prefix'       => array(
 				'file'     => '/formatting/file-header-php-open-tag-prefix.php',
 				'headers'  => array(
 					'TemplateName' => 'Template Name',
@@ -91,6 +92,16 @@ public function data_test_get_data_file() {
 					'TemplateName' => 'Something',
 				),
 			),
+			'php short open tag prefix' => array(
+				'file'     => '/formatting/file-header-php-short-open-tag-prefix.php',
+				'headers'  => array(
+					'TemplateName' => 'Template Name',
+				),
+				'context'  => '',
+				'expected' => array(
+					'TemplateName' => 'Something',
+				),
+			),
 		);
 	}
 }