Updates

wp-admin/includes/media.php

@@ -158,6 +158,22 @@ function get_image_send_to_editor($id, $caption, $title, $align, $url='', $rel =
  */
 function image_add_caption( $html, $id, $caption, $title, $align, $url, $size, $alt = '' ) {
 
+	/**
+	 * Filter the caption text.
+	 *
+	 * Note: If the caption text is empty, the caption shortcode will not be appended
+	 * to the image HTML when inserted into the editor.
+	 *
+	 * Passing an empty value also prevents the {@see 'image_add_caption_shortcode'}
+	 * filter from being evaluated at the end of {@see image_add_caption()}.
+	 *
+	 * @since 4.1.0
+	 *
+	 * @param string $caption The original caption text.
+	 * @param int    $id      The attachment ID.
+	 */
+	$caption = apply_filters( 'image_add_caption_text', $caption, $id );
+
 	/**
 	 * Filter whether to disable captions.
 	 *
@@ -223,24 +239,23 @@ function _cleanup_image_add_caption( $matches ) {
 function media_send_to_editor($html) {
 ?>
 <script type="text/javascript">
-/* <![CDATA[ */
 var win = window.dialogArguments || opener || parent || top;
 win.send_to_editor('<?php echo addslashes($html); ?>');
-/* ]]> */
 </script>
 <?php
 	exit;
 }
 
 /**
- * This handles the file upload POST itself, creating the attachment post.
+ * Save a file submitted from a POST request and create an attachment post for it.
  *
  * @since 2.5.0
  *
- * @param string $file_id Index into the {@link $_FILES} array of the upload
- * @param int $post_id The post ID the media is associated with
- * @param array $post_data allows you to overwrite some of the attachment
- * @param array $overrides allows you to override the {@link wp_handle_upload()} behavior
+ * @param string $file_id   Index of the {@link $_FILES} array that the file was sent. Required.
+ * @param int    $post_id   The post ID of a post to attach the media item to. Required, but can
+ *                          be set to 0, creating a media item that has no relationship to a post.
+ * @param array  $post_data Overwrite some of the attachment. Optional.
+ * @param array  $overrides Override the {@link wp_handle_upload()} behavior. Optional.
  * @return int|WP_Error ID of the attachment or a WP_Error object on failure.
  */
 function media_handle_upload($file_id, $post_id, $post_data = array(), $overrides = array( 'test_form' => false )) {
@@ -265,31 +280,31 @@ function media_handle_upload($file_id, $post_id, $post_data = array(), $override
 	$file = $file['file'];
 	$title = $name;
 	$content = '';
+	$excerpt = '';
 
 	if ( preg_match( '#^audio#', $type ) ) {
 		$meta = wp_read_audio_metadata( $file );
 
-		if ( ! empty( $meta['title'] ) )
+		if ( ! empty( $meta['title'] ) ) {
 			$title = $meta['title'];
-
-		$content = '';
+		}
 
 		if ( ! empty( $title ) ) {
 
 			if ( ! empty( $meta['album'] ) && ! empty( $meta['artist'] ) ) {
 				/* translators: 1: audio track title, 2: album title, 3: artist name */
 				$content .= sprintf( __( '"%1$s" from %2$s by %3$s.' ), $title, $meta['album'], $meta['artist'] );
-			} else if ( ! empty( $meta['album'] ) ) {
+			} elseif ( ! empty( $meta['album'] ) ) {
 				/* translators: 1: audio track title, 2: album title */
 				$content .= sprintf( __( '"%1$s" from %2$s.' ), $title, $meta['album'] );
-			} else if ( ! empty( $meta['artist'] ) ) {
+			} elseif ( ! empty( $meta['artist'] ) ) {
 				/* translators: 1: audio track title, 2: artist name */
 				$content .= sprintf( __( '"%1$s" by %2$s.' ), $title, $meta['artist'] );
 			} else {
 				$content .= sprintf( __( '"%s".' ), $title );
 			}
 
-		} else if ( ! empty( $meta['album'] ) ) {
+		} elseif ( ! empty( $meta['album'] ) ) {
 
 			if ( ! empty( $meta['artist'] ) ) {
 				/* translators: 1: audio album title, 2: artist name */
@@ -298,7 +313,7 @@ function media_handle_upload($file_id, $post_id, $post_data = array(), $override
 				$content .= $meta['album'] . '.';
 			}
 
-		} else if ( ! empty( $meta['artist'] ) ) {
+		} elseif ( ! empty( $meta['artist'] ) ) {
 
 			$content .= $meta['artist'] . '.';
 
@@ -319,11 +334,14 @@ function media_handle_upload($file_id, $post_id, $post_data = array(), $override
 			$content .= ' ' . sprintf( __( 'Genre: %s.' ), $meta['genre'] );
 
 	// Use image exif/iptc data for title and caption defaults if possible.
-	} elseif ( $image_meta = @wp_read_image_metadata( $file ) ) {
-		if ( trim( $image_meta['title'] ) && ! is_numeric( sanitize_title( $image_meta['title'] ) ) )
+	} elseif ( 0 === strpos( $type, 'image/' ) && $image_meta = @wp_read_image_metadata( $file ) ) {
+		if ( trim( $image_meta['title'] ) && ! is_numeric( sanitize_title( $image_meta['title'] ) ) ) {
 			$title = $image_meta['title'];
-		if ( trim( $image_meta['caption'] ) )
-			$content = $image_meta['caption'];
+		}
+
+		if ( trim( $image_meta['caption'] ) ) {
+			$excerpt = $image_meta['caption'];
+		}
 	}
 
 	// Construct the attachment array
@@ -333,6 +351,7 @@ function media_handle_upload($file_id, $post_id, $post_data = array(), $override
 		'post_parent' => $post_id,
 		'post_title' => $title,
 		'post_content' => $content,
+		'post_excerpt' => $excerpt,
 	), $post_data );
 
 	// This should never be set as it would then overwrite an existing attachment.
@@ -416,7 +435,7 @@ function media_handle_sideload($file_array, $post_id, $desc = null, $post_data =
  *
  * @since 2.5.0
  *
- * @param array $content_func
+ * @param string|callable $content_func
  */
 function wp_iframe($content_func /* ... */) {
 	_wp_admin_html_begin();
@@ -432,11 +451,9 @@ if ( ( is_array( $content_func ) && ! empty( $content_func[1] ) && 0 === strpos(
 wp_enqueue_style( 'ie' );
 ?>
 <script type="text/javascript">
-//<![CDATA[
 addLoadEvent = function(func){if(typeof jQuery!="undefined")jQuery(document).ready(func);else if(typeof wpOnload!='function'){wpOnload=func;}else{var oldonload=wpOnload;wpOnload=function(){oldonload();func();}}};
 var ajaxurl = '<?php echo admin_url( 'admin-ajax.php', 'relative' ); ?>', pagenow = 'media-upload-popup', adminpage = 'media-upload-popup',
 isRtl = <?php echo (int) is_rtl(); ?>;
-//]]>
 </script>
 <?php
 	/** This action is documented in wp-admin/admin-header.php */
@@ -478,7 +495,7 @@ if ( is_string( $content_func ) ) {
 	 * Fires in the admin header for each specific form tab in the legacy
 	 * (pre-3.5.0) media upload popup.
 	 *
-	 * The dynamic portion of the hook, $content_func, refers to the form
+	 * The dynamic portion of the hook, `$content_func`, refers to the form
 	 * callback for the media upload type. Possible values include
 	 * 'media_upload_type_form', 'media_upload_type_url_form', and
 	 * 'media_upload_library_form'.
@@ -554,6 +571,14 @@ function media_buttons($editor_id = 'content') {
 }
 add_action( 'media_buttons', 'media_buttons' );
 
+/**
+ *
+ * @global int $post_ID
+ * @param string $type
+ * @param int $post_id
+ * @param string $tab
+ * @return string
+ */
 function get_upload_iframe_src( $type = null, $post_id = null, $tab = null ) {
 	global $post_ID;
 
@@ -571,7 +596,7 @@ function get_upload_iframe_src( $type = null, $post_id = null, $tab = null ) {
 	/**
 	 * Filter the upload iframe source URL for a specific media type.
 	 *
-	 * The dynamic portion of the hook name, $type, refers to the type
+	 * The dynamic portion of the hook name, `$type`, refers to the type
 	 * of media uploaded.
 	 *
 	 * @since 3.0.0
@@ -596,8 +621,8 @@ function media_upload_form_handler() {
 	$errors = null;
 
 	if ( isset($_POST['send']) ) {
-		$keys = array_keys($_POST['send']);
-		$send_id = (int) array_shift($keys);
+		$keys = array_keys( $_POST['send'] );
+		$send_id = (int) reset( $keys );
 	}
 
 	if ( !empty($_POST['attachments']) ) foreach ( $_POST['attachments'] as $attachment_id => $attachment ) {
@@ -658,10 +683,8 @@ function media_upload_form_handler() {
 
 	if ( isset($_POST['insert-gallery']) || isset($_POST['update-gallery']) ) { ?>
 		<script type="text/javascript">
-		/* <![CDATA[ */
 		var win = window.dialogArguments || opener || parent || top;
 		win.tb_remove();
-		/* ]]> */
 		</script>
 		<?php
 		exit;
@@ -701,7 +724,7 @@ function media_upload_form_handler() {
  *
  * @since 2.5.0
  *
- * @return mixed
+ * @return null|string
  */
 function wp_media_upload_handler() {
 	$errors = array();
@@ -739,7 +762,7 @@ function wp_media_upload_handler() {
 			/**
 			 * Filter the URL sent to the editor for a specific media type.
 			 *
-			 * The dynamic portion of the hook name, $type, refers to the type
+			 * The dynamic portion of the hook name, `$type`, refers to the type
 			 * of media being sent.
 			 *
 			 * @since 3.3.0
@@ -806,9 +829,10 @@ function wp_media_upload_handler() {
  * @param string $file The URL of the image to download
  * @param int $post_id The post ID the media is to be associated with
  * @param string $desc Optional. Description of the image
+ * @param string $return Optional. What to return: an image tag (default) or only the src.
  * @return string|WP_Error Populated HTML img tag on success
  */
-function media_sideload_image( $file, $post_id, $desc = null ) {
+function media_sideload_image( $file, $post_id, $desc = null, $return = 'html' ) {
 	if ( ! empty( $file ) ) {
 		// Set variables for storage, fix file filename for query strings.
 		preg_match( '/[^\?]+\.(jpe?g|jpe|gif|png)\b/i', $file, $matches );
@@ -837,9 +861,15 @@ function media_sideload_image( $file, $post_id, $desc = null ) {
 
 	// Finally check to make sure the file has been saved, then return the HTML.
 	if ( ! empty( $src ) ) {
+		if ( $return === 'src' ) {
+			return $src;
+		}
+
 		$alt = isset( $desc ) ? esc_attr( $desc ) : '';
 		$html = "<img src='$src' alt='$alt' />";
 		return $html;
+	} else {
+		return new WP_Error( 'image_sideload_failed' );
 	}
 }
 
@@ -848,7 +878,7 @@ function media_sideload_image( $file, $post_id, $desc = null ) {
  *
  * @since 2.5.0
  *
- * @return unknown
+ * @return string|null
  */
 function media_upload_gallery() {
 	$errors = array();
@@ -871,7 +901,7 @@ function media_upload_gallery() {
  *
  * @since 2.5.0
  *
- * @return unknown
+ * @return string|null
  */
 function media_upload_library() {
 	$errors = array();
@@ -892,7 +922,7 @@ function media_upload_library() {
  *
  * @since 2.7.0
  *
- * @param object $post
+ * @param WP_Post $post
  * @param string $checked
  * @return string
  */
@@ -920,12 +950,11 @@ function image_align_input_fields( $post, $checked = '' ) {
  *
  * @since 2.7.0
  *
- * @param object $post
+ * @param WP_Post $post
  * @param bool|string $check
  * @return array
  */
 function image_size_input_fields( $post, $check = '' ) {
-
 	/**
 	 * Filter the names and labels of the default image sizes.
 	 *
@@ -941,50 +970,53 @@ function image_size_input_fields( $post, $check = '' ) {
 		'full'      => __( 'Full Size' )
 	) );
 
-		if ( empty($check) )
-			$check = get_user_setting('imgsize', 'medium');
+	if ( empty( $check ) ) {
+		$check = get_user_setting('imgsize', 'medium');
+	}
+	$out = array();
 
-		foreach ( $size_names as $size => $label ) {
-			$downsize = image_downsize($post->ID, $size);
-			$checked = '';
+	foreach ( $size_names as $size => $label ) {
+		$downsize = image_downsize( $post->ID, $size );
+		$checked = '';
 
-			// Is this size selectable?
-			$enabled = ( $downsize[3] || 'full' == $size );
-			$css_id = "image-size-{$size}-{$post->ID}";
+		// Is this size selectable?
+		$enabled = ( $downsize[3] || 'full' == $size );
+		$css_id = "image-size-{$size}-{$post->ID}";
 
-			// If this size is the default but that's not available, don't select it.
-			if ( $size == $check ) {
-				if ( $enabled )
-					$checked = " checked='checked'";
-				else
-					$check = '';
-			} elseif ( !$check && $enabled && 'thumbnail' != $size ) {
-				/*
-				 * If $check is not enabled, default to the first available size
-				 * that's bigger than a thumbnail.
-				 */
-				$check = $size;
+		// If this size is the default but that's not available, don't select it.
+		if ( $size == $check ) {
+			if ( $enabled ) {
 				$checked = " checked='checked'";
+			} else {
+				$check = '';
 			}
-
-			$html = "<div class='image-size-item'><input type='radio' " . disabled( $enabled, false, false ) . "name='attachments[$post->ID][image-size]' id='{$css_id}' value='{$size}'$checked />";
-
-			$html .= "<label for='{$css_id}'>$label</label>";
-
-			// Only show the dimensions if that choice is available.
-			if ( $enabled )
-				$html .= " <label for='{$css_id}' class='help'>" . sprintf( "(%d&nbsp;&times;&nbsp;%d)", $downsize[1], $downsize[2] ). "</label>";
-
-			$html .= '</div>';
-
-			$out[] = $html;
+		} elseif ( ! $check && $enabled && 'thumbnail' != $size ) {
+			/*
+			 * If $check is not enabled, default to the first available size
+			 * that's bigger than a thumbnail.
+			 */
+			$check = $size;
+			$checked = " checked='checked'";
 		}
 
-		return array(
-			'label' => __('Size'),
-			'input' => 'html',
-			'html'  => join("\n", $out),
-		);
+		$html = "<div class='image-size-item'><input type='radio' " . disabled( $enabled, false, false ) . "name='attachments[$post->ID][image-size]' id='{$css_id}' value='{$size}'$checked />";
+
+		$html .= "<label for='{$css_id}'>$label</label>";
+
+		// Only show the dimensions if that choice is available.
+		if ( $enabled ) {
+			$html .= " <label for='{$css_id}' class='help'>" . sprintf( "(%d&nbsp;&times;&nbsp;%d)", $downsize[1], $downsize[2] ). "</label>";
+		}
+		$html .= '</div>';
+
+		$out[] = $html;
+	}
+
+	return array(
+		'label' => __( 'Size' ),
+		'input' => 'html',
+		'html'  => join( "\n", $out ),
+	);
 }
 
 /**
@@ -992,7 +1024,7 @@ function image_size_input_fields( $post, $check = '' ) {
  *
  * @since 2.7.0
  *
- * @param object $post
+ * @param WP_Post $post
  * @param string $url_type
  * @return string
  */
@@ -1075,8 +1107,8 @@ function media_post_single_attachment_fields_to_edit( $form_fields, $post ) {
  *
  * @since 2.5.0
  *
- * @param WP_Post $post       The WP_Post attachment object.
- * @param array   $attachment An array of attachment metadata.
+ * @param array $post       The WP_Post attachment object converted to an array.
+ * @param array $attachment An array of attachment metadata.
  * @return array Filtered attachment post object.
  */
 function image_attachment_fields_to_save( $post, $attachment ) {
@@ -1101,7 +1133,7 @@ add_filter( 'attachment_fields_to_save', 'image_attachment_fields_to_save', 10,
  * @param string $html
  * @param integer $attachment_id
  * @param array $attachment
- * @return array
+ * @return string
  */
 function image_media_send_to_editor($html, $attachment_id, $attachment) {
 	$post = get_post($attachment_id);
@@ -1125,7 +1157,7 @@ add_filter('media_send_to_editor', 'image_media_send_to_editor', 10, 3);
  *
  * @since 2.5.0
  *
- * @param object $post
+ * @param WP_Post $post
  * @param array $errors
  * @return array
  */
@@ -1325,7 +1357,7 @@ function get_media_item( $attachment_id, $args = null ) {
 
 	$post_mime_types = get_post_mime_types();
 	$keys = array_keys( wp_match_mime_types( array_keys( $post_mime_types ), $post->post_mime_type ) );
-	$type = array_shift( $keys );
+	$type = reset( $keys );
 	$type_html = "<input type='hidden' id='type-of-$attachment_id' value='" . esc_attr( $type ) . "' />";
 
 	$form_fields = get_attachment_fields_to_edit( $post, $r['errors'] );
@@ -1696,13 +1728,13 @@ function media_upload_header() {
  *
  * @since 2.5.0
  *
- * @param unknown_type $errors
+ * @param array $errors
  */
 function media_upload_form( $errors = null ) {
 	global $type, $tab, $is_IE, $is_opera;
 
 	if ( ! _device_can_upload() ) {
-		echo '<p>' . sprintf( __('The web browser on your device cannot be used to upload files. You may be able to use the <a href="%s">native app for your device</a> instead.'), 'http://apps.wordpress.org/' ) . '</p>';
+		echo '<p>' . sprintf( __('The web browser on your device cannot be used to upload files. You may be able to use the <a href="%s">native app for your device</a> instead.'), 'https://apps.wordpress.org/' ) . '</p>';
 		return;
 	}
 
@@ -1780,6 +1812,14 @@ $plupload_init = array(
 	'multipart_params'    => $post_params,
 );
 
+// Currently only iOS Safari supports multiple files uploading but iOS 7.x has a bug that prevents uploading of videos
+// when enabled. See #29602.
+if ( wp_is_mobile() && strpos( $_SERVER['HTTP_USER_AGENT'], 'OS 7_' ) !== false &&
+	strpos( $_SERVER['HTTP_USER_AGENT'], 'like Mac OS X' ) !== false ) {
+
+	$plupload_init['multi_selection'] = false;
+}
+
 /**
  * Filter the default Plupload settings.
  *
@@ -1802,7 +1842,7 @@ if( !$large_size_w )
 	$large_size_w = 1024;
 ?>
 var resize_height = <?php echo $large_size_h; ?>, resize_width = <?php echo $large_size_w; ?>,
-wpUploaderInit = <?php echo json_encode($plupload_init); ?>;
+wpUploaderInit = <?php echo wp_json_encode( $plupload_init ); ?>;
 </script>
 
 <div id="plupload-upload-ui" class="hide-if-no-js">
@@ -1912,7 +1952,6 @@ function media_upload_type_form($type = 'file', $errors = null, $id = null) {
 <?php media_upload_form( $errors ); ?>
 
 <script type="text/javascript">
-//<![CDATA[
 jQuery(function($){
 	var preloaded = $(".media-item.preloaded");
 	if ( preloaded.length > 0 ) {
@@ -1920,7 +1959,6 @@ jQuery(function($){
 	}
 	updateMediaForm();
 });
-//]]>
 </script>
 <div id="media-items"><?php
 
@@ -1975,7 +2013,6 @@ function media_upload_type_url_form($type = null, $errors = null, $id = null) {
 <h3 class="media-title"><?php _e('Insert media from another website'); ?></h3>
 
 <script type="text/javascript">
-//<![CDATA[
 var addExtImage = {
 
 	width : '',
@@ -2052,21 +2089,19 @@ var addExtImage = {
 			return false;
 		}
 
-		document.getElementById('status_img').innerHTML = '<img src="<?php echo esc_url( admin_url( 'images/wpspin_light.gif' ) ); ?>" alt="" width="16" />';
+		document.getElementById('status_img').innerHTML = '<img src="<?php echo esc_url( admin_url( 'images/spinner-2x.gif' ) ); ?>" alt="" width="16" height="16" />';
 		t.preloadImg = new Image();
 		t.preloadImg.onload = t.updateImageData;
 		t.preloadImg.onerror = t.resetImageData;
 		t.preloadImg.src = src;
 	}
-}
+};
 
 jQuery(document).ready( function($) {
 	$('.media-types input').click( function() {
 		$('table.describe').toggleClass('not-image', $('#not-image').prop('checked') );
 	});
 });
-
-//]]>
 </script>
 
 <div id="media-items">
@@ -2269,7 +2304,7 @@ function media_upload_library_form($errors) {
 
 ?>
 
-<form id="filter" action="" method="get">
+<form id="filter" method="get">
 <input type="hidden" name="type" value="<?php echo esc_attr( $type ); ?>" />
 <input type="hidden" name="tab" value="<?php echo esc_attr( $tab ); ?>" />
 <input type="hidden" name="post_id" value="<?php echo (int) $post_id; ?>" />
@@ -2317,7 +2352,7 @@ foreach ( $post_mime_types as $mime_type => $label ) {
 /**
  * Filter the media upload mime type list items.
  *
- * Returned values should begin with an <li> tag.
+ * Returned values should begin with an `<li>` tag.
  *
  * @since 3.1.0
  *
@@ -2629,13 +2664,13 @@ function edit_form_image_editor( $post ) {
 			<?php if ( $open ) wp_image_editor( $attachment_id ); ?>
 		</div>
 	<?php
-	elseif ( $attachment_id && 0 === strpos( $post->post_mime_type, 'audio/' ) ):
+	elseif ( $attachment_id && wp_attachment_is( 'audio', $post ) ):
 
 		wp_maybe_generate_attachment_metadata( $post );
 
 		echo wp_audio_shortcode( array( 'src' => $att_url ) );
 
-	elseif ( $attachment_id && 0 === strpos( $post->post_mime_type, 'video/' ) ):
+	elseif ( $attachment_id && wp_attachment_is( 'video', $post ) ):
 
 		wp_maybe_generate_attachment_metadata( $post );
 
@@ -2860,7 +2895,7 @@ function wp_add_id3_tag_data( &$metadata, $data ) {
 	foreach ( array( 'id3v2', 'id3v1' ) as $version ) {
 		if ( ! empty( $data[$version]['comments'] ) ) {
 			foreach ( $data[$version]['comments'] as $key => $list ) {
-				if ( ! empty( $list ) ) {
+				if ( 'length' !== $key && ! empty( $list ) ) {
 					$metadata[$key] = reset( $list );
 					// Fix bug in byte stream analysis.
 					if ( 'terms_of_use' === $key && 0 === strpos( $metadata[$key], 'yright notice.' ) )
@@ -2898,7 +2933,7 @@ function wp_add_id3_tag_data( &$metadata, $data ) {
  * @since 3.6.0
  *
  * @param string $file Path to file.
- * @return array|boolean Returns array of metadata, if found.
+ * @return array|bool Returns array of metadata, if found.
  */
 function wp_read_video_metadata( $file ) {
 	if ( ! file_exists( $file ) )
@@ -2922,7 +2957,7 @@ function wp_read_video_metadata( $file ) {
 	if ( ! empty( $data['mime_type'] ) )
 		$metadata['mime_type'] = $data['mime_type'];
 	if ( ! empty( $data['playtime_seconds'] ) )
-		$metadata['length'] = (int) ceil( $data['playtime_seconds'] );
+		$metadata['length'] = (int) round( $data['playtime_seconds'] );
 	if ( ! empty( $data['playtime_string'] ) )
 		$metadata['length_formatted'] = $data['playtime_string'];
 	if ( ! empty( $data['video']['resolution_x'] ) )
@@ -2978,7 +3013,7 @@ function wp_read_audio_metadata( $file ) {
 	if ( ! empty( $data['mime_type'] ) )
 		$metadata['mime_type'] = $data['mime_type'];
 	if ( ! empty( $data['playtime_seconds'] ) )
-		$metadata['length'] = (int) ceil( $data['playtime_seconds'] );
+		$metadata['length'] = (int) round( $data['playtime_seconds'] );
 	if ( ! empty( $data['playtime_string'] ) )
 		$metadata['length_formatted'] = $data['playtime_string'];
 
@@ -2986,3 +3021,63 @@ function wp_read_audio_metadata( $file ) {
 
 	return $metadata;
 }
+
+/**
+ * Encapsulate logic for Attach/Detach actions
+ *
+ * @since 4.2.0
+ *
+ * @global wpdb $wpdb WordPress database abstraction object.
+ *
+ * @param int    $parent_id Attachment parent ID.
+ * @param string $action    Optional. Attach/detach action. Accepts 'attach' or 'detach'.
+ *                          Default 'attach'.
+ */
+function wp_media_attach_action( $parent_id, $action = 'attach' ) {
+	global $wpdb;
+
+	if ( ! $parent_id ) {
+		return;
+	}
+
+	if ( ! current_user_can( 'edit_post', $parent_id ) ) {
+		wp_die( __( 'You are not allowed to edit this post.' ) );
+	}
+	$ids = array();
+	foreach ( (array) $_REQUEST['media'] as $att_id ) {
+		$att_id = (int) $att_id;
+
+		if ( ! current_user_can( 'edit_post', $att_id ) ) {
+			continue;
+		}
+
+		$ids[] = $att_id;
+	}
+
+	if ( ! empty( $ids ) ) {
+		$ids_string = implode( ',', $ids );
+		if ( 'attach' === $action ) {
+			$result = $wpdb->query( $wpdb->prepare( "UPDATE $wpdb->posts SET post_parent = %d WHERE post_type = 'attachment' AND ID IN ( $ids_string )", $parent_id ) );
+		} else {
+			$result = $wpdb->query( "UPDATE $wpdb->posts SET post_parent = 0 WHERE post_type = 'attachment' AND ID IN ( $ids_string )" );
+		}
+
+		foreach ( $ids as $att_id ) {
+			clean_attachment_cache( $att_id );
+		}
+	}
+
+	if ( isset( $result ) ) {
+		$location = 'upload.php';
+		if ( $referer = wp_get_referer() ) {
+			if ( false !== strpos( $referer, 'upload.php' ) ) {
+				$location = remove_query_arg( array( 'attached', 'detach' ), $referer );
+			}
+		}
+
+		$key = 'attach' === $action ? 'attached' : 'detach';
+		$location = add_query_arg( array( $key => $result ), $location );
+		wp_redirect( $location );
+		exit;
+	}
+}