In 7.3.8.1 General slice segment data syntax of JCTVC-L1003_v24 the syntax calls byte_alignment when a new tile is detected.

The syntax for byte_alignment emits a 1 followed by zeros until the stream is aligned.

However, the decoder implementation in function TComInputBitstream::readOutTrailingBits of TComBitStream.cpp contains the code:

Void TComInputBitstream::readOutTrailingBits ()
{

UInt uiBits = 0;
while ( ( getNumBitsLeft() > 0 ) && (getNumBitsUntilByteAligned()!=0) )
{

read ( 1, uiBits );

}

}

which will not emit a 1 if the stream is already aligned.
This code is called from TDecSbac::updateContextTables when the CABAC engine needs to be reinitialized.

Which is the correct behaviour? (Or have I misunderstood something?)