[libxml2] Adding some missing NULL checks

[Daniel Veillard <veillard src gnome org>]

commit 3e0eec43196e9c4d770b9a932ad131316794f7b4
Author: Gaurav <g gupta samsung com>
Date:   Fri Jun 13 14:45:20 2014 +0800

    Adding some missing NULL checks
    
    in SAX2 DOM building code and in the HTML parser

 HTMLparser.c |    4 ++--
 SAX2.c       |    9 +++++++++
 2 files changed, 11 insertions(+), 2 deletions(-)
---
diff --git a/HTMLparser.c b/HTMLparser.c
index dff8e1d..c26389f 100644
--- a/HTMLparser.c
+++ b/HTMLparser.c
@@ -3671,13 +3671,13 @@ htmlParseStartTag(htmlParserCtxtPtr ctxt) {
     int i;
     int discardtag = 0;
 
-    if (ctxt->instate == XML_PARSER_EOF)
-        return(-1);
     if ((ctxt == NULL) || (ctxt->input == NULL)) {
        htmlParseErr(ctxt, XML_ERR_INTERNAL_ERROR,
                     "htmlParseStartTag: context error\n", NULL, NULL);
        return -1;
     }
+    if (ctxt->instate == XML_PARSER_EOF)
+        return(-1);
     if (CUR != '<') return -1;
     NEXT;
 
diff --git a/SAX2.c b/SAX2.c
index 2a22318..e616efe 100644
--- a/SAX2.c
+++ b/SAX2.c
@@ -1177,6 +1177,12 @@ xmlSAX2AttributeInternal(void *ctx, const xmlChar *fullname,
            val = xmlStringDecodeEntities(ctxt, value, XML_SUBSTITUTE_REF,
                                          0,0,0);
            ctxt->depth--;
+           if (val == NULL) {
+               xmlSAX2ErrMemory(ctxt, "xmlSAX2StartElement");
+               if (name != NULL)
+                   xmlFree(name);
+               return;
+           }
        } else {
            val = (xmlChar *) value;
        }
@@ -2572,6 +2578,9 @@ xmlSAX2Characters(void *ctx, const xmlChar *ch, int len)
                       (xmlDictOwns(ctxt->dict, lastChild->content))) {
                lastChild->content = xmlStrdup(lastChild->content);
            }
+           if (lastChild->content == NULL) {
+               xmlSAX2ErrMemory(ctxt, "xmlSAX2Characters: xmlStrdup returned NULL");
+           }
             if (((size_t)ctxt->nodelen + (size_t)len > XML_MAX_TEXT_LENGTH) &&
                 ((ctxt->options & XML_PARSE_HUGE) == 0)) {
                 xmlSAX2ErrMemory(ctxt, "xmlSAX2Characters: huge text node");