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, 2 insertions, 2 deletions

diff --git a/sdext/source/presenter/PresenterController.cxx b/sdext/source/presenter/PresenterController.cxx
index a7771ea220ac..6b348dd40b76 100644
--- a/sdext/source/presenter/PresenterController.cxx
+++ b/sdext/source/presenter/PresenterController.cxx
@@ -382,13 +382,13 @@ void PresenterController::UpdatePaneTitles()
             if (nStartIndex < 0)
             {
                 // Add the remaining part of the string.
-                sResult.append(sTemplate.copy(nIndex));
+                sResult.appendCopy(sTemplate, nIndex);
                 break;
             }
             else
             {
                 // Add the part preceding the next %.
-                sResult.append(sTemplate.copy(nIndex, nStartIndex-nIndex));
+                sResult.appendCopy(sTemplate, nIndex, nStartIndex-nIndex);
 
                 // Get the placeholder
                 ++nStartIndex;