Did Mormon Leaders Concoct The Da Vinci Code?

Random House, publisher of The Da Vinci Code is being sued in Great Britain for a type of copyright infringement. According to the New York Times:

"Speaking before a packed courtroom in London's High Court, Jonathan Rayner James, the lawyer for the aggrieved authors, Michael Baigent and Richard Leigh, said that Mr. [Dan] Brown had 'appropriated' the 'architecture' and central argument of their book The Holy Blood and the Holy Grail (1982) in The Da Vinci Code, published in 2003."

A central theme in the question is the assertion, found in both The Holy Blood and the Holy Grail (1982) and The Da Vinci Code, that Jesus was married to Mary Magdalene. Random House affirms that Dan Brown consulted The Holy Blood and the Holy Grail before he published The Da Vinci Code. However,

"Random House's lawyers argue that The Holy Blood and the Holy Grail is just one of many sources Mr. Brown consulted, and that it was relatively unimportant to his research. Furthermore, they say, many of the basic ideas put forward in The Holy Blood and the Holy Grail were not original, anyway, but had been around for years in other sources."

Indeed, the claim that Jesus was married to Mary Magdalene has been around at least since the early days of Mormonism.

LDS Apostles Orson Hyde and Orson Pratt were outspoken on this subject in the 19th century. One example:

"It will be borne in mind that once on a time, there was a marriage in Cana of Galilee; and on a careful reading of that transaction, it will be discovered that no less a person than Jesus Christ was married on that occasion. If he was never married, his intimacy with Mary and Martha, and the other Mary also whom Jesus loved, must have been highly unbecoming and improper to say the best of it." (Orson Hyde, Journal of Discourses 4:259).

Wilford Woodruff, then an LDS Apostle, recorded the teaching of President Joseph F. Smith, who later became the 4th LDS Prophet:

"Evening Meeting. Prayer By E Stephenson. Joseph F Smith spoke One hour & 25 M. He spoke upon the Marriage in Cana at Galilee. He thought Jesus was the Bridgegroom and Mary & Martha the brides. He also refered to Luke 10 ch. 38 to 42 verse, Also John 11 ch. 2 & 5 vers John 12 Ch 3d vers, John 20 8 to 18. Joseph Smith spoke upon these passages to show that Mary & Martha manifested much Closer relationship than Merely A Believer which looks Consistet. He did not think that Jesus who decended throug Poligamous families from Abraham down & who fulfilled all the Law even baptism by immersion would have lived and died without being married." (Wilford Woodruff's Journal 8:187, July 22, 1883. Spelling, etc., retained from the original).

Even Brigham Young endorsed the idea that Jesus was married. Responding to the charge that polygamy was one of the "relics of barbarism," Brigham Young said,

"Yes, one of the relics of Adam, of Enoch, of Noah, of Abraham, of Isaac, of Jacob, of Moses, David, Solomon, the Prophets, of Jesus, and his Apostles" (Journal of Discourses 11:328).