From b8e0fa3489b344d9cbd1165687e7dc5b15cc3727 Mon Sep 17 00:00:00 2001
From: Hugh Davenport <hugh@davenport.net.nz>
Date: Wed, 4 May 2016 10:55:49 +0800
Subject: [PATCH]     Fix null pointer deref in docs with no root element

    From https://bugzilla.gnome.org/show_bug.cgi?id=758514
---
 xmllint.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/xmllint.c b/xmllint.c
index 9e85c11b..00f1769f 100644
--- a/xmllint.c
+++ b/xmllint.c
@@ -2002,6 +2002,12 @@ static void walkDoc(xmlDocPtr doc) {
     xmlNsPtr ns;
 
     root = xmlDocGetRootElement(doc);
+    if (root == NULL ) {
+        xmlGenericError(xmlGenericErrorContext,
+                "Document does not have a root element");
+        progresult = XMLLINT_ERR_UNCLASS;
+        return;
+    }
     for (ns = root->nsDef, i = 0;ns != NULL && i < 20;ns=ns->next) {
         namespaces[i++] = ns->href;
         namespaces[i++] = ns->prefix;