XLIFF Filter: sdlrep element in sdl:prev-origin cause incorrect repetition flag

Some segments may have two sdl:rep elements: one “normal”, the other inside an sdl:prev-origin element. The current code does not make any distinction, so it counts more repetitions that there is. For example if we have two segmenst with such case, we will get a count of 3 instead of 1. In addition, the first segment will have its repetition property set when it should not.

We need to take in account only the “normal” sdl:rep.