[libxml++] Document: write_to_*(): Make sure that we write UTF-8 out.

[Murray Cumming <murrayc src gnome org>]

commit 556478216b4344e8d78cc562338ec6616bd8a366
Author: Murray Cumming <murrayc murrayc com>
Date:   Fri Sep 9 11:02:45 2011 +0200

    Document: write_to_*(): Make sure that we write UTF-8 out.
    
    	* libxml++/document.cc: Because the xmlDocDump*() functions use some other
    	encoding if you specify NULL, causing errors such as:
    	xmlEscapeEntities : char out of range

 ChangeLog            |    8 ++++++++
 libxml++/document.cc |   22 +++++++++++++++++++---
 2 files changed, 27 insertions(+), 3 deletions(-)
---
diff --git a/ChangeLog b/ChangeLog
index 698d023..a40418d 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,11 @@
+2011-09-09  Murray Cumming  <murrayc murrayc com>
+
+	Document: write_to_*(): Make sure that we write UTF-8 out.
+
+	* libxml++/document.cc: Because the xmlDocDump*() functions use some other 
+	encoding if you specify NULL, causing errors such as:
+	xmlEscapeEntities : char out of range
+
 2.34.2:
 
 2011-09-06  Mathias Lorente  <mathias lorente free fr>
diff --git a/libxml++/document.cc b/libxml++/document.cc
index 6eec443..0be6a67 100644
--- a/libxml++/document.cc
+++ b/libxml++/document.cc
@@ -22,6 +22,19 @@
 namespace xmlpp
 {
 
+static const char* get_encoding_or_utf8(const Glib::ustring& encoding)
+{
+  if(encoding.empty())
+  {
+    //If we don't specify this to the xmlDocDump* functions (using 0 instead),
+    //then some other encoding is used, causing them to fail on non-ASCII characters.
+    return "UTF-8";
+  }
+  else
+    return encoding.c_str();
+}
+
+
 Document::Init::Init()
 {
   xmlInitParser(); //Not always necessary, but necessary for thread safety.
@@ -199,7 +212,8 @@ void Document::do_write_to_file(
 {
   KeepBlanks k(KeepBlanks::Default);
   xmlIndentTreeOutput = format?1:0;
-  const int result = xmlSaveFormatFileEnc(filename.c_str(), impl_, encoding.empty() ? 0 : encoding.c_str(), format?1:0);
+  const int result = xmlSaveFormatFileEnc(filename.c_str(), impl_,
+    get_encoding_or_utf8(encoding), format?1:0);
 
   if(result == -1)
   {
@@ -220,7 +234,8 @@ Glib::ustring Document::do_write_to_string(
   xmlChar* buffer = 0;
   int length = 0;
 
-  xmlDocDumpFormatMemoryEnc(impl_, &buffer, &length, encoding.empty() ? 0 : encoding.c_str(), format?1:0);
+  xmlDocDumpFormatMemoryEnc(impl_, &buffer, &length,
+    get_encoding_or_utf8(encoding), format?1:0);
 
   if(!buffer)
   {
@@ -248,7 +263,8 @@ 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);
-  const int result = xmlSaveFormatFileTo(buffer.cobj(), impl_, encoding.c_str(), format ? 1 : 0);
+  const int result = xmlSaveFormatFileTo(buffer.cobj(), impl_,
+    get_encoding_or_utf8(encoding), format ? 1 : 0);
   
   if(result == -1)
   {