Potential porting bug in map_params_dirac_to_stereo

Basic info

• Float reference:
  • Encoder (float):
  • Decoder (float): 2a32cceaf0d7ce3482cb05e5c12951e95a8a552a
• Fixed point:
  • Encoder (fixed):
  • Decoder (fixed): a8ff39cd

Bug description

This took a bit of looking but it seems that there is indexing bug done in porting for shift step. See below:

Float

            /* Clamp values here. [-1, 1] is the allowed range, but due to precision issues they can be slightly off which can cause problems later. */
            side_gain[b] *= sqrtf( 1.f - diffuseness[b] );
            side_gain[b] = max( min( side_gain[b], 1 ), -1 );
            side_gain[b + STEREO_DFT_BAND_MAX] *= sqrtf( 1.f - diffuseness[b] );
            side_gain[b + STEREO_DFT_BAND_MAX] = max( min( side_gain[b + STEREO_DFT_BAND_MAX], 1 ), -1 );

BASOP

            /* Clamp values here. [-1, 1] is the allowed range, but due to precision issues they can be slightly off which can cause problems later. */
            /* In Q31, this clamping happens implicitly */
            q_sqrt = 0;
            move16();
            side_gain[b] = Mpy_32_32( side_gain[b], Sqrt32( L_sub( MAX_32, diffuseness[b] ), &q_sqrt ) ); /*Q31 - q_sqrt*/
            move32();
            IF( q_sqrt )
            {
                side_gain[b] = L_shl( side_gain[b], q_sqrt ); /*Q31*/
                q_sqrt = 0;
                move16();
            }
            side_gain[b + STEREO_DFT_BAND_MAX] = Mpy_32_32( side_gain[b + STEREO_DFT_BAND_MAX], Sqrt32( L_sub( MAX_32, diffuseness[b] ), &q_sqrt ) ); /*Q31 - q_sqrt*/
            move32();
            IF( q_sqrt )
            {
BUG HERE -->    side_gain[b + STEREO_DFT_BAND_MAX] = L_shl( side_gain[b], q_sqrt ); /*Q31*/
                q_sqrt = 0;
                move16();
            }

I am pretty sure that the assignment should be done from side_gain[b + STEREO_DFT_BAND_MAX] if I understand this correctly.