clean up UNO available() implementations

There seems to be some confusion here. available() is actually the
number of bytes that can be read without blocking, but most
implementations seems to be just returning the number of bytes remaining
in the stream. Since we're doing that, let's do it properly.

(*) some of them were just casting, instead of clamping, which will
return wrong values sometimes.
(*) FileStreamWrapper_Impl/OInputStreamWrapper/OTempFileService were
doing unnecessary work, instead of just asking the underlying SvStream
for it's remaining size

Change-Id: I3ef26e0363e989ed3e00be0fdb993e1cdeb7819f
Reviewed-on: https://gerrit.libreoffice.org/57264
Tested-by: Jenkins
Reviewed-by: Noel Grandin <noel.grandin@collabora.co.uk>

1 files changed, 1 insertions, 1 deletions

diff --git a/ucbhelper/source/provider/fd_inputstream.cxx b/ucbhelper/source/provider/fd_inputstream.cxx
index 32c56b40b0fa..b34e39646a4f 100644
--- a/ucbhelper/source/provider/fd_inputstream.cxx
+++ b/ucbhelper/source/provider/fd_inputstream.cxx
@@ -99,7 +99,7 @@ namespace ucbhelper
 
     sal_Int32 SAL_CALL FdInputStream::available()
     {
-        return sal::static_int_cast<sal_Int32>(m_nLength - getPosition());
+        return std::min<sal_Int64>(SAL_MAX_INT32, m_nLength - getPosition());
     }