PVS-Studio warning V501 for Skia

void SkCanvasStack::pushCanvas(....) {
  ....
  for (int i = fList.count() - 1; i > 0; --i) {
    SkIRect localBounds = canvasBounds;
    localBounds.offset(origin - fCanvasData[i-1].origin);

    fCanvasData[i-1].requiredClip.op(localBounds,
                                     SkRegion::kDifference_Op);
    fList[i-i]->clipRegion(fCanvasData[i-1].requiredClip);
  }
  ....
}

Most likely this is what should be written here: fList[i-1]->

This suspicious code was found in Skia project by PVS-Studio static code analyzer.
Warning message is:
V501 There are identical sub-expressions to the left and to the right of the '-' operator: i - i SkCanvasStack.cpp 38

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