[libxml2] Free input buffer in xmlHaltParser

[Nick Wellnhofer <nwellnhof src gnome org>]

commit 123234f2cfcd9e9b9f83047eee1dc17b4c3f4407
Author: Nick Wellnhofer <wellnhofer aevum de>
Date:   Tue Sep 11 14:52:07 2018 +0200

    Free input buffer in xmlHaltParser
    
    This avoids miscalculation of available bytes.
    
    Thanks to Yunho Kim for the report.
    
    Closes: #26

 parser.c                     |  5 +++++
 result/errors/759573.xml.err | 17 +++++++----------
 2 files changed, 12 insertions(+), 10 deletions(-)
---
diff --git a/parser.c b/parser.c
index ca9fde2c..5813a664 100644
--- a/parser.c
+++ b/parser.c
@@ -12462,7 +12462,12 @@ xmlHaltParser(xmlParserCtxtPtr ctxt) {
            ctxt->input->free((xmlChar *) ctxt->input->base);
            ctxt->input->free = NULL;
        }
+        if (ctxt->input->buf != NULL) {
+            xmlFreeParserInputBuffer(ctxt->input->buf);
+            ctxt->input->buf = NULL;
+        }
        ctxt->input->cur = BAD_CAST"";
+        ctxt->input->length = 0;
        ctxt->input->base = ctxt->input->cur;
         ctxt->input->end = ctxt->input->cur;
     }
diff --git a/result/errors/759573.xml.err b/result/errors/759573.xml.err
index 554039f6..38ef5c40 100644
--- a/result/errors/759573.xml.err
+++ b/result/errors/759573.xml.err
@@ -21,14 +21,11 @@ Entity: line 1:
             ^
 ./test/errors/759573.xml:1: parser error : internal error: xmlParseInternalSubset: error detected in Markup 
declaration
 
-<?h?><!DOCTYPEt[<!ELEMENT t (A)><!ENTITY % xx '&#37;<![INCLUDE[000&#37;&#3000;00
-     ^
+
+^
 ./test/errors/759573.xml:1: parser error : DOCTYPE improperly terminated
-<?h?><!DOCTYPEt[<!ELEMENT t (A)><!ENTITY % xx '&#37;<![INCLUDE[000&#37;&#3000;00
-     ^
-./test/errors/759573.xml:1: parser error : StartTag: invalid element name
-<?h?><!DOCTYPEt[<!ELEMENT t (A)><!ENTITY % xx '&#37;<![INCLUDE[000&#37;&#3000;00
-      ^
-./test/errors/759573.xml:1: parser error : Extra content at the end of the document
-<?h?><!DOCTYPEt[<!ELEMENT t (A)><!ENTITY % xx '&#37;<![INCLUDE[000&#37;&#3000;00
-      ^
+
+^
+./test/errors/759573.xml:1: parser error : Start tag expected, '<' not found
+
+^