diff --git a/wp-includes/class-wp-embed.php b/wp-includes/class-wp-embed.php
index f536f71a04..1cd4d6252c 100644
--- a/wp-includes/class-wp-embed.php
+++ b/wp-includes/class-wp-embed.php
@@ -311,7 +311,7 @@ class WP_Embed {
 	 * @return string Potentially modified $content.
 	 */
 	public function autoembed( $content ) {
-		return preg_replace_callback( '|^\s*(https?://[^\s"]+)\s*$|im', array( $this, 'autoembed_callback' ), $content );
+		return preg_replace_callback( '|^(\s*)(https?://[^\s"]+)(\s*)$|im', array( $this, 'autoembed_callback' ), $content );
 	}
 
 	/**
@@ -323,10 +323,10 @@ class WP_Embed {
 	public function autoembed_callback( $match ) {
 		$oldval = $this->linkifunknown;
 		$this->linkifunknown = false;
-		$return = $this->shortcode( array(), $match[1] );
+		$return = $this->shortcode( array(), $match[2] );
 		$this->linkifunknown = $oldval;
 
-		return "\n$return\n";
+		return $match[1] . $return . $match[3];
 	}
 
 	/**
diff --git a/wp-includes/version.php b/wp-includes/version.php
index 5ddb6e9384..2d30ec6c14 100644
--- a/wp-includes/version.php
+++ b/wp-includes/version.php
@@ -4,7 +4,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '4.2-alpha-31065';
+$wp_version = '4.2-alpha-31066';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.