[libxml++] Check some libxml function return values.

[Murray Cumming <murrayc src gnome org>]

commit f23a72661f395b444f962a7636055f860ba1167c
Author: Murray Cumming <murrayc murrayc com>
Date:   Fri Nov 26 15:51:16 2010 +0100

    Check some libxml function return values.
    
    	* libxml++/document.cc: do_write_to_stream():
    	* libxml++/schema.cc: set_document(): Check the results from
    	xmlSchemaNewDocParserCtxt() and xmlSaveFormatFileTo().
    	Bug #635846 (Markus Elfring).

 ChangeLog            |    9 +++++++++
 libxml++/document.cc |   15 +++++++++++----
 libxml++/schema.cc   |   22 +++++++++++++++++++---
 3 files changed, 39 insertions(+), 7 deletions(-)
---
diff --git a/ChangeLog b/ChangeLog
index 0709564..45f72f8 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,12 @@
+2010-11-26  Murray Cumming  <murrayc murrayc com>
+
+	Check some libxml function return values.
+
+	* libxml++/document.cc: do_write_to_stream():
+	* libxml++/schema.cc: set_document(): Check the results from 
+	xmlSchemaNewDocParserCtxt() and xmlSaveFormatFileTo().
+	Bug #635846 (Markus Elfring).
+
 2.33.1:
 
 2010-11-14  Murray Cumming  <murrayc murrayc com>
diff --git a/libxml++/document.cc b/libxml++/document.cc
index df159fb..6eec443 100644
--- a/libxml++/document.cc
+++ b/libxml++/document.cc
@@ -199,9 +199,7 @@ void Document::do_write_to_file(
 {
   KeepBlanks k(KeepBlanks::Default);
   xmlIndentTreeOutput = format?1:0;
-  int result = 0;
-
-  result = xmlSaveFormatFileEnc(filename.c_str(), impl_, encoding.empty() ? 0 : encoding.c_str(), format?1:0);
+  const int result = xmlSaveFormatFileEnc(filename.c_str(), impl_, encoding.empty() ? 0 : encoding.c_str(), format?1:0);
 
   if(result == -1)
   {
@@ -250,7 +248,16 @@ void Document::do_write_to_stream(std::ostream& output, const Glib::ustring& enc
 {
   // TODO assert document encoding is UTF-8 if encoding is different than UTF-8
   OStreamOutputBuffer buffer(output, encoding);
-  xmlSaveFormatFileTo(buffer.cobj(), impl_, encoding.c_str(), format?1:0);
+  const int result = xmlSaveFormatFileTo(buffer.cobj(), impl_, encoding.c_str(), format ? 1 : 0);
+  
+  if(result == -1)
+  {
+    #ifdef LIBXMLCPP_EXCEPTIONS_ENABLED
+    throw exception("do_write_to_stream() failed.");
+    #else
+    return;
+    #endif //LIBXMLCPP_EXCEPTIONS_ENABLED
+  }
 }
 
 void Document::set_entity_declaration(const Glib::ustring& name, XmlEntityType type,
diff --git a/libxml++/schema.cc b/libxml++/schema.cc
index 12d400b..a589083 100644
--- a/libxml++/schema.cc
+++ b/libxml++/schema.cc
@@ -37,14 +37,30 @@ void Schema::set_document(Document* document, bool embed)
   release_underlying();
 
   xmlSchemaParserCtxtPtr context = xmlSchemaNewDocParserCtxt( document->cobj() );
-  impl_ = xmlSchemaParse( context );
+
+  if(!context)
+  {
 #ifdef LIBXMLCPP_EXCEPTIONS_ENABLED
-  if ( !impl_ )
    throw parse_error("Schema could not be parsed");
+#else
+   return;
 #endif
+  }
+  
+  impl_ = xmlSchemaParse(context);
+  if(!impl_)
+  {
+    xmlSchemaFreeParserCtxt(context);
+#ifdef LIBXMLCPP_EXCEPTIONS_ENABLED
+    throw parse_error("Schema could not be parsed");
+#else
+    return;
+#endif
+  }
+
   impl_->_private = this;
   embedded_doc_ = embed;
-  xmlSchemaFreeParserCtxt( context );
+  xmlSchemaFreeParserCtxt(context);
 }
 
 Glib::ustring Schema::get_name() const