ofz#2538: avoid oom

and merge together checkSeeks

Change-Id: I341a09404280fb8d4acfbe2abaed47e2830af55f
Reviewed-on: https://gerrit.libreoffice.org/39800
Reviewed-by: Caolán McNamara <caolanm@redhat.com>
Tested-by: Caolán McNamara <caolanm@redhat.com>

1 files changed, 6 insertions, 0 deletions

diff --git a/tools/source/stream/stream.cxx b/tools/source/stream/stream.cxx
index cdfac8273470..8c8d294f1164 100644
--- a/tools/source/stream/stream.cxx
+++ b/tools/source/stream/stream.cxx
@@ -1392,6 +1392,12 @@ sal_uInt64 SvStream::Seek(sal_uInt64 const nFilePos)
     return m_nBufFilePos + m_nBufActualPos;
 }
 
+bool checkSeek(SvStream &rSt, sal_uInt64 nOffset)
+{
+    const sal_uInt64 nMaxSeek(rSt.Tell() + rSt.remainingSize());
+    return (nOffset <= nMaxSeek && rSt.Seek(nOffset) == nOffset);
+}
+
 //STREAM_SEEK_TO_END in the some of the Seek backends is special cased to be
 //efficient, in others e.g. SotStorageStream it's really horribly slow, and in
 //those this should be overridden