MFC r331926:
r330675 introduced an extra window check in the LRO code to ensure it captured and reported the highest window advertisement with the same SEQ/ACK. However, the window comparison uses modulo 2**16 math, rather than directly comparing the absolute values. Because windows use absolute values and not modulo 2**16 math (i.e. they don't wrap), we need to compare the absolute values.
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