[libxml2] Avoid memory leak if xmlParserInputBufferCreateIO fails

[Daniel Veillard <veillard src gnome org>]

commit 24464be6390bc61a0f0e17890fbfc9c581434e29
Author: Lin Yi-Li <record nctu cis91 gmail com>
Date:   Thu May 10 16:14:55 2012 +0800

    Avoid memory leak if xmlParserInputBufferCreateIO fails
    
    For https://bugzilla.gnome.org/show_bug.cgi?id=643949
    
    In case of error on an IO creation input the given context
    is terminated with the given close function, except if the
    error happened in xmlParserInputBufferCreateIO. This can
    lead to a resource leak which is fixed by this patch.

 HTMLparser.c |   10 ++++++++--
 parser.c     |   26 ++++++++++++++++++--------
 xmlreader.c  |   13 ++++++++++---
 3 files changed, 36 insertions(+), 13 deletions(-)
---
diff --git a/HTMLparser.c b/HTMLparser.c
index 2eb3fb4..bf15c6a 100644
--- a/HTMLparser.c
+++ b/HTMLparser.c
@@ -6780,8 +6780,11 @@ htmlReadIO(xmlInputReadCallback ioread, xmlInputCloseCallback ioclose,
 
     input = xmlParserInputBufferCreateIO(ioread, ioclose, ioctx,
                                          XML_CHAR_ENCODING_NONE);
-    if (input == NULL)
+    if (input == NULL) {
+        if (ioclose != NULL)
+            ioclose(ioctx);
         return (NULL);
+    }
     ctxt = htmlNewParserCtxt();
     if (ctxt == NULL) {
         xmlFreeParserInputBuffer(input);
@@ -6980,8 +6983,11 @@ htmlCtxtReadIO(htmlParserCtxtPtr ctxt, xmlInputReadCallback ioread,
 
     input = xmlParserInputBufferCreateIO(ioread, ioclose, ioctx,
                                          XML_CHAR_ENCODING_NONE);
-    if (input == NULL)
+    if (input == NULL) {
+        if (ioclose != NULL)
+            ioclose(ioctx);
         return (NULL);
+    }
     stream = xmlNewIOInputStream(ctxt, input, XML_CHAR_ENCODING_NONE);
     if (stream == NULL) {
         xmlFreeParserInputBuffer(input);
diff --git a/parser.c b/parser.c
index 7ea5a88..b39aa59 100644
--- a/parser.c
+++ b/parser.c
@@ -11984,11 +11984,15 @@ xmlCreateIOParserCtxt(xmlSAXHandlerPtr sax, void *user_data,
     xmlParserCtxtPtr ctxt;
     xmlParserInputPtr inputStream;
     xmlParserInputBufferPtr buf;
-    
+
     if (ioread == NULL) return(NULL);
 
     buf = xmlParserInputBufferCreateIO(ioread, ioclose, ioctx, enc);
-    if (buf == NULL) return(NULL);
+    if (buf == NULL) {
+        if (ioclose != NULL)
+            ioclose(ioctx);
+        return (NULL);
+    }
 
     ctxt = xmlNewParserCtxt();
     if (ctxt == NULL) {
@@ -12013,7 +12017,7 @@ xmlCreateIOParserCtxt(xmlSAXHandlerPtr sax, void *user_data,
 	    memcpy(ctxt->sax, sax, sizeof(xmlSAXHandlerV1));
 	if (user_data != NULL)
 	    ctxt->userData = user_data;
-    }	
+    }
 
     inputStream = xmlNewIOInputStream(ctxt, buf, enc);
     if (inputStream == NULL) {
@@ -14787,7 +14791,7 @@ xmlReadFd(int fd, const char *URL, const char *encoding, int options)
  * @options:  a combination of xmlParserOption
  *
  * parse an XML document from I/O functions and source and build a tree.
- * 
+ *
  * Returns the resulting document tree
  */
 xmlDocPtr
@@ -14803,8 +14807,11 @@ xmlReadIO(xmlInputReadCallback ioread, xmlInputCloseCallback ioclose,
 
     input = xmlParserInputBufferCreateIO(ioread, ioclose, ioctx,
                                          XML_CHAR_ENCODING_NONE);
-    if (input == NULL)
+    if (input == NULL) {
+        if (ioclose != NULL)
+            ioclose(ioctx);
         return (NULL);
+    }
     ctxt = xmlNewParserCtxt();
     if (ctxt == NULL) {
         xmlFreeParserInputBuffer(input);
@@ -14830,7 +14837,7 @@ xmlReadIO(xmlInputReadCallback ioread, xmlInputCloseCallback ioclose,
  *
  * parse an XML in-memory document and build a tree.
  * This reuses the existing @ctxt parser context
- * 
+ *
  * Returns the resulting document tree
  */
 xmlDocPtr
@@ -14985,7 +14992,7 @@ xmlCtxtReadFd(xmlParserCtxtPtr ctxt, int fd,
  *
  * parse an XML document from I/O functions and source and build a tree.
  * This reuses the existing @ctxt parser context
- * 
+ *
  * Returns the resulting document tree
  */
 xmlDocPtr
@@ -15006,8 +15013,11 @@ xmlCtxtReadIO(xmlParserCtxtPtr ctxt, xmlInputReadCallback ioread,
 
     input = xmlParserInputBufferCreateIO(ioread, ioclose, ioctx,
                                          XML_CHAR_ENCODING_NONE);
-    if (input == NULL)
+    if (input == NULL) {
+        if (ioclose != NULL)
+            ioclose(ioctx);
         return (NULL);
+    }
     stream = xmlNewIOInputStream(ctxt, input, XML_CHAR_ENCODING_NONE);
     if (stream == NULL) {
         xmlFreeParserInputBuffer(input);
diff --git a/xmlreader.c b/xmlreader.c
index 864abf0..ef41927 100644
--- a/xmlreader.c
+++ b/xmlreader.c
@@ -5401,8 +5401,11 @@ xmlReaderForIO(xmlInputReadCallback ioread, xmlInputCloseCallback ioclose,
 
     input = xmlParserInputBufferCreateIO(ioread, ioclose, ioctx,
                                          XML_CHAR_ENCODING_NONE);
-    if (input == NULL)
+    if (input == NULL) {
+        if (ioclose != NULL)
+            ioclose(ioctx);
         return (NULL);
+    }
     reader = xmlNewTextReader(input, URL);
     if (reader == NULL) {
         xmlFreeParserInputBuffer(input);
@@ -5619,10 +5622,14 @@ xmlReaderNewIO(xmlTextReaderPtr reader, xmlInputReadCallback ioread,
 
     input = xmlParserInputBufferCreateIO(ioread, ioclose, ioctx,
                                          XML_CHAR_ENCODING_NONE);
-    if (input == NULL)
-        return (-1);
+    if (input == NULL) {
+        if (ioclose != NULL)
+            ioclose(ioctx);
+        return (NULL);
+    }
     return (xmlTextReaderSetup(reader, input, URL, encoding, options));
 }
+
 /************************************************************************
  *									*
  *			Utilities					*