Index: wp-includes/query.php
IDEA additional info:
Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP
<+>UTF-8
===================================================================
--- wp-includes/query.php	(revision 207ba54fede57a10f9d604716159eb63b50bfd4c)
+++ wp-includes/query.php	(revision )
@@ -1645,7 +1645,7 @@
 		} else {
 			// Look for archive queries. Dates, categories, authors, search, post type archives.
 
-			if ( isset( $this->query['s'] ) ) {
+			if ( isset( $this->query['s'] ) && strlen($this->query['s'] )) {
 				$this->is_search = true;
 			}