[libxml2] Add xmlHaltParser() to stop the parser

[Daniel Veillard <veillard src gnome org>]

commit 28cd9cb747a94483f4aea7f0968d202c20bb4cfc
Author: Daniel Veillard <veillard redhat com>
Date:   Fri Nov 20 14:55:30 2015 +0800

    Add xmlHaltParser() to stop the parser
    
    The problem is doing it in a consistent and safe fashion
    It's more complex than just setting ctxt->instate = XML_PARSER_EOF
    Update the public function to reuse that new internal routine

 parser.c |   34 +++++++++++++++++++++++++++++-----
 1 files changed, 29 insertions(+), 5 deletions(-)
---
diff --git a/parser.c b/parser.c
index da6e729..b6e99b1 100644
--- a/parser.c
+++ b/parser.c
@@ -94,6 +94,8 @@ static xmlParserCtxtPtr
 xmlCreateEntityParserCtxtInternal(const xmlChar *URL, const xmlChar *ID,
                          const xmlChar *base, xmlParserCtxtPtr pctx);
 
+static void xmlHaltParser(xmlParserCtxtPtr ctxt);
+
 /************************************************************************
  *                                                                     *
  *     Arbitrary limits set in the parser. See XML_PARSE_HUGE          *
@@ -12625,25 +12627,47 @@ xmlCreatePushParserCtxt(xmlSAXHandlerPtr sax, void *user_data,
 #endif /* LIBXML_PUSH_ENABLED */
 
 /**
- * xmlStopParser:
+ * xmlHaltParser:
  * @ctxt:  an XML parser context
  *
- * Blocks further parser processing
+ * Blocks further parser processing don't override error
+ * for internal use
  */
-void
-xmlStopParser(xmlParserCtxtPtr ctxt) {
+static void
+xmlHaltParser(xmlParserCtxtPtr ctxt) {
     if (ctxt == NULL)
         return;
     ctxt->instate = XML_PARSER_EOF;
-    ctxt->errNo = XML_ERR_USER_STOP;
     ctxt->disableSAX = 1;
     if (ctxt->input != NULL) {
+        /*
+        * in case there was a specific allocation deallocate before
+        * overriding base
+        */
+        if (ctxt->input->free != NULL) {
+           ctxt->input->free((xmlChar *) ctxt->input->base);
+           ctxt->input->free = NULL;
+       }
        ctxt->input->cur = BAD_CAST"";
        ctxt->input->base = ctxt->input->cur;
     }
 }
 
 /**
+ * xmlStopParser:
+ * @ctxt:  an XML parser context
+ *
+ * Blocks further parser processing
+ */
+void
+xmlStopParser(xmlParserCtxtPtr ctxt) {
+    if (ctxt == NULL)
+        return;
+    xmlHaltParser(ctxt);
+    ctxt->errNo = XML_ERR_USER_STOP;
+}
+
+/**
  * xmlCreateIOParserCtxt:
  * @sax:  a SAX handler
  * @user_data:  The user data returned on SAX callbacks