pdf: extract XMP metadata writing and use XmlWriter

Instead of writing XMP metadata with a string buffer, change to
use XmlWriter instead. Extract XMP metadata writing into its own
class vcl::pdf::XmpMetadata.

This also needs a change to the XmlWriter to not write a classic
XML header: '<?xml version="1.0" ... ?>'

Change-Id: I95ea0e7ba58e7c43a0c707bf9c676994210ff104
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/85908
Reviewed-by: Tomaž Vajngerl <quikee@gmail.com>
Tested-by: Tomaž Vajngerl <quikee@gmail.com>

1 files changed, 8 insertions, 3 deletions

diff --git a/tools/source/xml/XmlWriter.cxx b/tools/source/xml/XmlWriter.cxx
index 3400a6e9d94b..a314eed6e940 100644
--- a/tools/source/xml/XmlWriter.cxx
+++ b/tools/source/xml/XmlWriter.cxx
@@ -36,11 +36,13 @@ struct XmlWriterImpl
     XmlWriterImpl(SvStream* pStream)
         : mpStream(pStream)
         , mpWriter(nullptr)
+        , mbWriteXmlHeader(true)
     {
     }
 
     SvStream* const mpStream;
     xmlTextWriterPtr mpWriter;
+    bool mbWriteXmlHeader;
 };
 
 XmlWriter::XmlWriter(SvStream* pStream)
@@ -54,21 +56,24 @@ XmlWriter::~XmlWriter()
         endDocument();
 }
 
-bool XmlWriter::startDocument(sal_Int32 nIndent)
+bool XmlWriter::startDocument(sal_Int32 nIndent, bool bWriteXmlHeader)
 {
+    mpImpl->mbWriteXmlHeader = bWriteXmlHeader;
     xmlOutputBufferPtr xmlOutBuffer
         = xmlOutputBufferCreateIO(funcWriteCallback, funcCloseCallback, mpImpl->mpStream, nullptr);
     mpImpl->mpWriter = xmlNewTextWriter(xmlOutBuffer);
     if (mpImpl->mpWriter == nullptr)
         return false;
     xmlTextWriterSetIndent(mpImpl->mpWriter, nIndent);
-    xmlTextWriterStartDocument(mpImpl->mpWriter, nullptr, "UTF-8", nullptr);
+    if (mpImpl->mbWriteXmlHeader)
+        xmlTextWriterStartDocument(mpImpl->mpWriter, nullptr, "UTF-8", nullptr);
     return true;
 }
 
 void XmlWriter::endDocument()
 {
-    xmlTextWriterEndDocument(mpImpl->mpWriter);
+    if (mpImpl->mbWriteXmlHeader)
+        xmlTextWriterEndDocument(mpImpl->mpWriter);
     xmlFreeTextWriter(mpImpl->mpWriter);
     mpImpl->mpWriter = nullptr;
 }