WP_HTTP: When requesting a document with HTTP/1.1 include the 'Connection: Close' header (unless a Connection header is already specified) to prevent the connection being held open and hanging the request process. See #23463

git-svn-id: https://develop.svn.wordpress.org/trunk@25150 602fd350-edb4-49c9-b593-d223f7449a82

src/wp-includes/class-http.php

@@ -172,6 +172,10 @@ class WP_Http {
 			unset( $r['headers']['user-agent'] );
 		}
 
+		if ( '1.1' == $r['httpversion'] && !isset( $r['headers']['connection'] ) ) {
+			$r['headers']['connection'] = 'close';
+		}
+
 		// Construct Cookie: header if any cookies are set
 		WP_Http::buildCookieHeader( $r );