[xml] Encoding

[Echoes <echoes free fr>]

  Hello,

 I'm dumping a DOM tree to a string using xmlDocDumpMemory().
So far so good. 
But when now I want to specifiy the encoding used (ISO-8859-1)
so I use xmlDocDumpMemoryEnc(doc, &res, &size, "ISO-8859-1");

 It fails with this error :
xmlDocDumpFormatMemoryEnc: Source document not in UTF8

 Note that it always fails whatever encoding i tried.

 I guess I'm missing something during the creation of the tree ?

 Thanks

        Eugène