Ticket #21848: 21848.2.diff

src/wp-admin/includes/ajax-actions.php

@@ -2446 +2446 @@
                 $size = isset( $attachment['image-size'] ) ? $attachment['image-size'] : 'medium';
                 $alt = isset( $attachment['image_alt'] ) ? $attachment['image_alt'] : '';
                 $caption = isset( $attachment['post_excerpt'] ) ? $attachment['post_excerpt'] : '';
+                $caption = trim( $caption );
                 $title = ''; // We no longer insert title tags into <img> tags, as they are redundant.
                 $html = get_image_send_to_editor( $id, $caption, $title, $align, $url, (bool) $rel, $size, $alt );
         } elseif ( wp_attachment_is( 'video', $post ) || wp_attachment_is( 'audio', $post )  ) {