Taken from http://www.openwall.com/lists/oss-security/2016/09/25/10

Upstream-Status: Backport
Index: bash-4.3/parse.y
===================================================================
--- bash-4.3.orig/parse.y	2014-09-26 13:10:44.340080056 -0700
+++ bash-4.3/parse.y	2014-09-26 13:11:44.764080056 -0700
@@ -2953,6 +2953,8 @@
   FREE (word_desc_to_read);
   word_desc_to_read = (WORD_DESC *)NULL;
 
+  eol_ungetc_lookahead = 0;
+
   current_token = '\n';		/* XXX */
   last_read_token = '\n';
   token_to_read = '\n';