Additional way to calculate the request body size.

Author: Stephen Seliuk

src/Facebook/HttpClients/FacebookCurlHttpClient.php

@@ -295,8 +295,11 @@ private function getHeaderSize()
     // This corrects a Curl bug where header size does not account
     // for additional Proxy headers.
     if ( self::needsCurlProxyFix() ) {
-      if ( stripos($this->rawResponse, self::CONNECTION_ESTABLISHED) !== false ) {
-        $headerSize += mb_strlen(self::CONNECTION_ESTABLISHED);
+      // Additional way to calculate the request body size.
+      if (preg_match('/Content-Length: (\d+)/', $this->rawResponse, $m)) {
+          $headerSize = mb_strlen($this->rawResponse) - $m[1];
+      } elseif (stripos($this->rawResponse, self::CONNECTION_ESTABLISHED) !== false) {
+          $headerSize += mb_strlen(self::CONNECTION_ESTABLISHED);
       }
     }