Index: wp-includes/post-formats.php
===================================================================
--- wp-includes/post-formats.php	(revision 23827)
+++ wp-includes/post-formats.php	(working copy)
@@ -342,7 +342,7 @@
 			if ( ! empty( $meta['quote'] ) && ! stristr( $content, $meta['quote'] ) ) {
 				$quote = sprintf( '<blockquote>%s</blockquote>', wpautop( $meta['quote'] ) );
 				if ( ! empty( $meta['quote_source'] ) ) {
-					$source = ( empty( $quote_meta['url'] ) ) ? $meta['quote_source'] : sprintf( '<a href="%s">%s</a>', esc_url( $meta['url'] ), $meta['quote_source'] );
+					$source = ( empty( $meta['url'] ) ) ? $meta['quote_source'] : sprintf( '<a href="%s">%s</a>', esc_url( $meta['url'] ), $meta['quote_source'] );
 					$quote .= sprintf( '<figcaption class="quote-caption">%s</figcaption>', $source );
 				}
 				$format_output .= sprintf( '<figure class="quote">%s</figure>', $quote );