Macs tend to fare second best in Consumer Reports testing, partly because the magazine lives in ignorance of the differences between Apple’s computers and Windows boxes. But they’ve always been recommended, until recently. I can quibble about the way the tests appear to emphasize features over performance, usability and reliability. In fact, I have. But it took a poor rating by CR to trigger a dialogue that revealed a serious flaw in their testing. The tests also triggered an obscure bug in Safari for macOS Sierra that might otherwise have remained undiscovered and unfixed. It all started when CR reported...