create appendCopy method in OUStringBuffer

so we can avoid temporary copies when appending a substring of an
OUString to the buffer. I would have preferred to call the method just
"append" but that results in ambiguous method errors when the callsite
is something like
   sal_Int32 n;
   OUStringBuffer s;
   s.append(n, 10);
I'm not sure why

Change-Id: I6b5b6641fcb5b26ce2269f89ef06e03c0b6aa76f
Reviewed-on: https://gerrit.libreoffice.org/58666
Tested-by: Jenkins
Reviewed-by: Noel Grandin <noel.grandin@collabora.co.uk>

1 files changed, 1 insertions, 1 deletions

diff --git a/sax/source/tools/converter.cxx b/sax/source/tools/converter.cxx
index e8bd90f02c21..416ada3f4ce4 100644
--- a/sax/source/tools/converter.cxx
+++ b/sax/source/tools/converter.cxx
@@ -754,7 +754,7 @@ void Converter::convertDuration(OUStringBuffer& rBuffer,
         if ( aNS.getLength() > 2 )
         {
             rBuffer.append( '.');
-            rBuffer.append( aNS.copy( 2 ) );     // strip "0."
+            rBuffer.appendCopy( aNS, 2 );     // strip "0."
         }
     }
     rBuffer.append( 'S');