Index: wp-admin/includes/media.php
===================================================================
--- wp-admin/includes/media.php	(revision 18057)
+++ wp-admin/includes/media.php	(working copy)
@@ -1295,39 +1295,45 @@
 		'extra_rows' => array(),
 	);
 
-	if ( $send )
-		$send = get_submit_button( __( 'Insert into Post' ), 'button', "send[$attachment_id]", false );
-	if ( $delete && current_user_can( 'delete_post', $attachment_id ) ) {
-		if ( !EMPTY_TRASH_DAYS ) {
-			$delete = "<a href='" . wp_nonce_url( "post.php?action=delete&amp;post=$attachment_id", 'delete-attachment_' . $attachment_id ) . "' id='del[$attachment_id]' class='delete'>" . __( 'Delete Permanently' ) . '</a>';
-		} elseif ( !MEDIA_TRASH ) {
-			$delete = "<a href='#' class='del-link' onclick=\"document.getElementById('del_attachment_$attachment_id').style.display='block';return false;\">" . __( 'Delete' ) . "</a>
-			 <div id='del_attachment_$attachment_id' class='del-attachment' style='display:none;'>" . sprintf( __( 'You are about to delete <strong>%s</strong>.' ), $filename ) . "
-			 <a href='" . wp_nonce_url( "post.php?action=delete&amp;post=$attachment_id", 'delete-attachment_' . $attachment_id ) . "' id='del[$attachment_id]' class='button'>" . __( 'Continue' ) . "</a>
-			 <a href='#' class='button' onclick=\"this.parentNode.style.display='none';return false;\">" . __( 'Cancel' ) . "</a>
-			 </div>";
-		} else {
-			$delete = "<a href='" . wp_nonce_url( "post.php?action=trash&amp;post=$attachment_id", 'trash-attachment_' . $attachment_id ) . "' id='del[$attachment_id]' class='delete'>" . __( 'Move to Trash' ) . "</a>
-			<a href='" . wp_nonce_url( "post.php?action=untrash&amp;post=$attachment_id", 'untrash-attachment_' . $attachment_id ) . "' id='undo[$attachment_id]' class='undo hidden'>" . __( 'Undo' ) . "</a>";
+	if ( !isset( $form_fields['buttons'] ) ) {
+
+		$buttons = array();
+
+		if ( $send )
+			$buttons['send'] = get_submit_button( __( 'Insert into Post' ), 'button', "send[$attachment_id]", false );
+		if ( $delete && current_user_can( 'delete_post', $attachment_id ) ) {
+			if ( !EMPTY_TRASH_DAYS ) {
+				$buttons['delete'] = "<a href='" . wp_nonce_url( "post.php?action=delete&amp;post=$attachment_id", 'delete-attachment_' . $attachment_id ) . "' id='del[$attachment_id]' class='delete'>" . __( 'Delete Permanently' ) . '</a>';
+			} elseif ( !MEDIA_TRASH ) {
+				$buttons['delete'] = "<a href='#' class='del-link' onclick=\"document.getElementById('del_attachment_$attachment_id').style.display='block';return false;\">" . __( 'Delete' ) . "</a>
+				 <div id='del_attachment_$attachment_id' class='del-attachment' style='display:none;'>" . sprintf( __( 'You are about to delete <strong>%s</strong>.' ), $filename ) . "
+				 <a href='" . wp_nonce_url( "post.php?action=delete&amp;post=$attachment_id", 'delete-attachment_' . $attachment_id ) . "' id='del[$attachment_id]' class='button'>" . __( 'Continue' ) . "</a>
+				 <a href='#' class='button' onclick=\"this.parentNode.style.display='none';return false;\">" . __( 'Cancel' ) . "</a>
+				 </div>";
+			} else {
+				$buttons['delete'] = "<a href='" . wp_nonce_url( "post.php?action=trash&amp;post=$attachment_id", 'trash-attachment_' . $attachment_id ) . "' id='del[$attachment_id]' class='delete'>" . __( 'Move to Trash' ) . "</a>
+				<a href='" . wp_nonce_url( "post.php?action=untrash&amp;post=$attachment_id", 'untrash-attachment_' . $attachment_id ) . "' id='undo[$attachment_id]' class='undo hidden'>" . __( 'Undo' ) . "</a>";
+			}
 		}
-	} else {
-		$delete = '';
+	
+		if ( 'image' == $type ) {
+			$calling_post_id = 0;
+			if ( isset( $_GET['post_id'] ) )
+				$calling_post_id = absint( $_GET['post_id'] );
+			elseif ( isset( $_POST ) && count( $_POST ) ) // Like for async-upload where $_GET['post_id'] isn't set
+				$calling_post_id = $post->post_parent;
+			if ( $calling_post_id && current_theme_supports( 'post-thumbnails', get_post_type( $calling_post_id ) ) && get_post_thumbnail_id( $calling_post_id ) != $attachment_id ) {
+				$ajax_nonce = wp_create_nonce( "set_post_thumbnail-$calling_post_id" );
+				$buttons['thumbnail'] = "<a class='wp-post-thumbnail' id='wp-post-thumbnail-" . $attachment_id . "' href='#' onclick='WPSetAsThumbnail(\"$attachment_id\", \"$ajax_nonce\");return false;'>" . esc_html__( "Use as featured image" ) . "</a>";
+			}
+		}
+	
+		if ( count( $buttons ) )
+			$form_fields['buttons'] = array( 'tr' => "\t\t<tr class='submit'><td></td><td class='savesend'>" .
+				implode( ' ', apply_filters( 'media_item_buttons', $buttons ) ) .
+				"</td></tr>\n" );
 	}
 
-	$thumbnail = '';
-	$calling_post_id = 0;
-	if ( isset( $_GET['post_id'] ) )
-		$calling_post_id = absint( $_GET['post_id'] );
-	elseif ( isset( $_POST ) && count( $_POST ) ) // Like for async-upload where $_GET['post_id'] isn't set
-		$calling_post_id = $post->post_parent;
-	if ( 'image' == $type && $calling_post_id && current_theme_supports( 'post-thumbnails', get_post_type( $calling_post_id ) ) && get_post_thumbnail_id( $calling_post_id ) != $attachment_id ) {
-		$ajax_nonce = wp_create_nonce( "set_post_thumbnail-$calling_post_id" );
-		$thumbnail = "<a class='wp-post-thumbnail' id='wp-post-thumbnail-" . $attachment_id . "' href='#' onclick='WPSetAsThumbnail(\"$attachment_id\", \"$ajax_nonce\");return false;'>" . esc_html__( "Use as featured image" ) . "</a>";
-	}
-
-	if ( ( $send || $thumbnail || $delete ) && !isset( $form_fields['buttons'] ) )
-		$form_fields['buttons'] = array( 'tr' => "\t\t<tr class='submit'><td></td><td class='savesend'>$send $thumbnail $delete</td></tr>\n" );
-
 	$hidden_fields = array();
 
 	foreach ( $form_fields as $id => $field ) {