“From Hollywood With Love: The Rise and Fall (and Rise Again) of the Romantic Comedy,” by Scott Meslow (Dey St.), out Feb. 1.Here are surprising stories from six of the most beloved rom-coms of the past few decades.In the initial script for 1989 film “When Harry Met Sally,” the two title characters, played by Billy Crystal and Meg Ryan, went their separate ways at the end.But a funny thing happened on the way to a bummer ending.Director Rob Reiner, after almost a decade of being single, fell in love.“I just had them walking in opposite directions at the end,” Reiner says in the book.“And then I met the woman who became my wife during the making of the movie, and I changed the ending.” (Reiner and his wife Michele married in 1989 and are still together.)But the main characters of “When Harry Met Sally” are actually stand-ins for Reiner and the film’s writer, Nora Ephron, who spent many hours arguing about the differences between men and women when it comes to sex and relationships.“Ephron wanted to know: What is it actually like to be a single man?” writes Meslow.