[libxml2] Catch malloc error and exit accordingly

[Daniel Veillard <veillard src gnome org>]

commit e71dce18a1a72578581d4e91c24a44eead0d5949
Author: Daniel Veillard <veillard redhat com>
Date:   Thu Jul 11 15:41:22 2013 +0800

    Catch malloc error and exit accordingly
    
    As pointed privately by Bill Parker <wp02855 gmail com>

 xmllint.c |    4 ++++
 1 files changed, 4 insertions(+), 0 deletions(-)
---
diff --git a/xmllint.c b/xmllint.c
index c0196ab..4d464e4 100644
--- a/xmllint.c
+++ b/xmllint.c
@@ -3090,6 +3090,10 @@ static void usage(const char *name) {
 static void registerNode(xmlNodePtr node)
 {
     node->_private = malloc(sizeof(long));
+    if (node->_private == NULL) {
+        fprintf(stderr, "Out of memory in xmllint:registerNode()\n");
+       exit(XMLLINT_ERR_MEM);
+    }
     *(long*)node->_private = (long) 0x81726354;
     nbregister++;
 }