PVS-Studio warning V610 for WebP

void VP8YUVInit(void) {
  ....
  for (i = 0; i < 256; ++i) {
    VP8kVToR[i] = (89858 * (i - 128) + YUV_HALF) >> YUV_FIX;
    VP8kUToG[i] = -22014 * (i - 128) + YUV_HALF;
    VP8kVToG[i] = -45773 * (i - 128);
    VP8kUToB[i] = (113618 * (i - 128) + YUV_HALF) >> YUV_FIX;
  }
  ....
}

This suspicious code was found in WebP project by PVS-Studio static code analyzer.
Warning message is:
V610 Unspecified behavior. Check the shift operator '>>. The left operand is negative ('(89858 * (i - 128) + YUV_HALF)' = [-11469056..11444734]). yuv.c 40

PVS-Studio is a static analyzer for detecting bugs in the source code of applications written in C, C++, C++11, C++/CX. Site: http://www.viva64.com/en/pvs-studio/