deploy some asserts to detect truncated STREAM_SEEK_TO_END

Since STREAM_SEEK_TO_END is now 64 bits it could happen that some
existing code uses it in some indirect manner and it gets truncated to
32 bits somewhere (on 32 bit platforms); try to detect that with asserts.

Of course the checked value is now a valid stream position, so
perhaps the checks should eventually be removed.

Change-Id: I4248c00d758220bdc3ee94c7aa7a7bd4c86c57f0

3 files changed, 10 insertions, 0 deletions

diff --git a/tools/source/stream/stream.cxx b/tools/source/stream/stream.cxx
index 48cae55f0169..9921d6f8a4dc 100644
--- a/tools/source/stream/stream.cxx
+++ b/tools/source/stream/stream.cxx
@@ -308,6 +308,8 @@ ErrCode SvAsyncLockBytes::FillAppend(const void * pBuffer, sal_Size nCount,
 // virtual
 sal_uInt64 SvAsyncLockBytes::Seek(sal_uInt64 const nPos)
 {
+    // check if a truncated STREAM_SEEK_TO_END was passed
+    assert(nPos != (sal_uInt64)(sal_uInt32)STREAM_SEEK_TO_END);
     if (nPos != STREAM_SEEK_TO_END)
         m_nSize = nPos;
     return m_nSize;
@@ -343,6 +345,8 @@ sal_Size SvStream::PutData( const void* pData, sal_Size nSize )
 
 sal_uInt64 SvStream::SeekPos(sal_uInt64 const nPos)
 {
+    // check if a truncated STREAM_SEEK_TO_END was passed
+    assert(nPos != (sal_uInt64)(sal_uInt32)STREAM_SEEK_TO_END);
     if( !GetError() && nPos == STREAM_SEEK_TO_END )
     {
         DBG_ASSERT( xLockBytes.Is(), "pure virtual function" );
@@ -1839,6 +1843,8 @@ sal_uInt64 SvMemoryStream::SeekPos(sal_uInt64 const nNewPos)
     // nEndOfData: First position in stream not allowed to read from
     // nSize: Size of allocated buffer
 
+    // check if a truncated STREAM_SEEK_TO_END was passed
+    assert(nNewPos != (sal_uInt64)(sal_uInt32)STREAM_SEEK_TO_END);
     if( nNewPos < nEndOfData )
         nPos = nNewPos;
     else if( nNewPos == STREAM_SEEK_TO_END )
diff --git a/tools/source/stream/strmunx.cxx b/tools/source/stream/strmunx.cxx
index 010bcc6660c6..c3144ed3bd57 100644
--- a/tools/source/stream/strmunx.cxx
+++ b/tools/source/stream/strmunx.cxx
@@ -358,6 +358,8 @@ sal_Size SvFileStream::PutData( const void* pData, sal_Size nSize )
 
 sal_uInt64 SvFileStream::SeekPos(sal_uInt64 const nPos)
 {
+    // check if a truncated STREAM_SEEK_TO_END was passed
+    assert(nPos != (sal_uInt64)(sal_uInt32)STREAM_SEEK_TO_END);
     if ( IsOpen() )
     {
         oslFileError rc;
diff --git a/tools/source/stream/strmwnt.cxx b/tools/source/stream/strmwnt.cxx
index d5f519fcef05..ad4f1336339b 100644
--- a/tools/source/stream/strmwnt.cxx
+++ b/tools/source/stream/strmwnt.cxx
@@ -162,6 +162,8 @@ sal_Size SvFileStream::PutData( const void* pData, sal_Size nSize )
 
 sal_uInt64 SvFileStream::SeekPos(sal_uInt64 const nPos)
 {
+    // check if a truncated STREAM_SEEK_TO_END was passed
+    assert(nPos != (sal_uInt64)(sal_uInt32)STREAM_SEEK_TO_END);
     DWORD nNewPos = 0;
     if( IsOpen() )
     {