[libxml2] Fix large parse of file from memory

[Daniel Veillard <veillard src gnome org>]

commit 153cf15905cf4ec080612ada6703757d10caba1e
Author: Daniel Veillard <veillard redhat com>
Date:   Fri Oct 26 13:50:47 2012 +0800

    Fix large parse of file from memory
    
    https://bugzilla.redhat.com/show_bug.cgi?id=862969
    The new code trying to detect excessive input lookup would
    just get wrong sometimes in the case of very large file parsed
    directly from memory.

 libxml.h |    2 ++
 parser.c |    1 +
 xmlIO.c  |    2 +-
 3 files changed, 4 insertions(+), 1 deletions(-)
---
diff --git a/libxml.h b/libxml.h
index efe285b..7558b5f 100644
--- a/libxml.h
+++ b/libxml.h
@@ -91,6 +91,8 @@ void __xmlGlobalInitMutexDestroy(void);
 int __xmlRandom(void);
 #endif
 
+int xmlNop(void);
+
 #ifdef IN_LIBXML
 #ifdef __GNUC__
 #ifdef PIC
diff --git a/parser.c b/parser.c
index 43f53d9..0d8d7f2 100644
--- a/parser.c
+++ b/parser.c
@@ -2025,6 +2025,7 @@ static void xmlSHRINK (xmlParserCtxtPtr ctxt) {
 static void xmlGROW (xmlParserCtxtPtr ctxt) {
     if ((((ctxt->input->end - ctxt->input->cur) > XML_MAX_LOOKUP_LIMIT) ||
          ((ctxt->input->cur - ctxt->input->base) > XML_MAX_LOOKUP_LIMIT)) &&
+         ((ctxt->input->buf) && (ctxt->input->buf->readcallback != xmlNop)) &&
         ((ctxt->options & XML_PARSE_HUGE) == 0)) {
         xmlFatalErr(ctxt, XML_ERR_INTERNAL_ERROR, "Huge input lookup");
         ctxt->instate = XML_PARSER_EOF;
diff --git a/xmlIO.c b/xmlIO.c
index f8f438b..44254e4 100644
--- a/xmlIO.c
+++ b/xmlIO.c
@@ -800,7 +800,7 @@ xmlCheckFilename (const char *path)
     return 1;
 }
 
-static int
+int
 xmlNop(void) {
     return(0);
 }