A caret straight after a newline is on a line with nothing to measure — the shape a trailing-newline draft ends in. chromium returns no client rects at all for the collapsed position (an all-zero box, which sent the reveal upward instead), firefox reports the line above, WebKit the right one. Measure the newline the caret just left and step one line down: all three then land on 649 of 652 with the caret's line at 315 inside the 336px box. The browser case now pastes a newline-terminated block, and fails 'expected 0 to be greater than 0' without the rule.
creatixchu
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