LOS ANGELES — There’s a scene in “42” in which Jackie Robinson, the first black player in modern Major League Baseball, endures intolerably cruel racial slurs from the Philadelphia Phillies’ manager.

It’s early in the 1947 season. Each time the Brooklyn Dodgers’ first baseman comes up to bat, manager Ben Chapman emerges from the dugout, stands on the field and taunts him with increasingly personal and vitriolic attacks. It’s a visible struggle, but No. 42 maintains his composure before a crowd of thousands.

As a viewer, it’s uncomfortable to watch — although as writer-director Brian Helgeland points out, “if anything, the language we have in that scene was cleaned up from what it was.”…