Madonna's Alleged Stalker -- Facing Trial ... AGAIN

Talk about getting someone's hopes up -- TMZ has learned, a New York judge has decided to reinstate charges against a crazed fan arrested outside Madonna's apartment two years ago ... after previously dismissing his case.

As we reported, a retired FDNY firefighter named Robert Linhart was arrested in September 2010, carrying a sign that read, "M, the Universe brought us together in 1992 and again this year in Prague. Meet me please XXX."

Linhart was charged with criminal mischief, graffiti, and possession of a weapon -- an ice pick he allegedly had in his car.

But lucky for him, prosecutors failed to bring him to trial within 180 days of his original indictment -- per the speedy trial act (everyone has a right to a speedy trial blah blah blah). So, a judge dismissed Linhart's case in March 2012.

But Linhart's luck was short-lived -- and yesterday, a NY judge decided the 180 days were previously miscalculated. Now, prosecutors have 15 more days to bring Linhart to trial.