Question: Ivanhoé is an 1826 pastiche opera in three acts with music by Gioachino Rossini, the  music was adapted, with the composer's permission, by the music-publisher Antonio Pacini from Rossini's operas, namely La gazza ladra, is a "melodramma" or opera semiseria in two acts by Gioachino Rossini, with a libretto by who?
Context: The Barber of Seville, or The Useless Precaution (Italian: Il barbiere di Siviglia, ossia L'inutile precauzione ] ) is an opera buffa in two acts by Gioachino Rossini with an Italian libretto by Cesare Sterbini.  The libretto was based on Pierre Beaumarchais's French comedy "Le Barbier de Séville" (1775).  The première of Rossini's opera (under the title "Almaviva, o sia L'inutile precauzione") took place on 20 February 1816 at the Teatro Argentina, Rome. The Thieving Magpie (La Gazza Ladra) is a double live album by the British neo-progressive rock band Marillion.  It was named after the introductory piece of classical music the band used before coming on stage during the "Clutching at Straws" tour 1987–1988, the overture to Rossini's opera "La gazza ladra", which translates as "The Thieving Magpie". La gazza ladra (] , The Thieving Magpie) is a "melodramma" or opera semiseria in two acts by Gioachino Rossini, with a libretto by Giovanni Gherardini based on "La pie voleuse" by Théodore Baudouin d'Aubigny and Louis-Charles Caigniez. Matilde di Shabran (full title: Matilde di Shabran, o sia Bellezza e Cuor di ferro; English: Matilde of Shabran, or Beauty and Ironheart) is a "melodramma giocoso" in two acts by Gioachino Rossini to a libretto by Jacopo Ferretti after François-Benoît Hoffman’s libretto for Méhul’s "Euphrosine" (1790, Paris) and J. M. Boutet de Monvel's play "Mathilde".  The opera was first performed in Rome at the Teatro Apollo, 24 February 1821 La pietra del paragone (The Touchstone) is an opera, or melodramma giocoso, in two acts by Gioachino Rossini, to an original Italian libretto by Luigi Romanelli. Tancredi is a "melodramma eroico" (opera seria or 'heroic' opera) in two acts by composer Gioachino Rossini and librettist Gaetano Rossi (who was also to write "Semiramide" ten years later), based on Voltaire's play "Tancrède" (1760).  The opera made its first appearance at the Teatro La Fenice in Venice on 6 February 1813, and because "Il signor Bruschino" premiered in late January, the composer must have completed "Tancredi" in less than a month.  The overture, borrowed from "La pietra del paragone", is a popular example of Rossini's characteristic style and is regularly performed in concert and recorded. Ivanhoé is an 1826 pastiche opera in three acts with music by Gioachino Rossini to a French-language libretto by Émile Deschamps and Gabriel-Gustave de Wailly, after Walter Scott's novel of the same name.  The music was adapted, with the composer's permission, by the music-publisher Antonio Pacini from Rossini's operas, namely "Semiramide", "La Cenerentola", "La gazza ladra", and "Tancredi" in order to introduce his music to Paris.  An examination of the score shows that Pacini also used music from "Bianca e Faliero", "Armida", "Maometto II", "Aureliano in Palmira", "Sigismondo", "Torvaldo e Dorliska", "Mosè in Egitto" and an amount of newly composed music including fanfares and the gallop that was later to become famous from its inclusion in "Guglielmo Tell".  The work was premiered on 15 September 1826, at the Odéon Theatre. Robert Bruce is an 1846 pastiche opera in three acts, with music by Gioachino Rossini and Louis Niedermeyer to a French-language libretto by Alphonse Royer and Gustave Vaëz, after Walter Scott's "History of Scotland".  The music was stitched together by Niedermeyer, with the composer's permission, with pieces from "La donna del lago", "Zelmira", and other Rossini operas.  The work was premiered on 30 December 1846, by the Paris Opera at the Salle Le Peletier.  The audience may not have noticed, but the orchestra included for the first time a recently invented instrument, which later came to be known as the saxophone. Ciro in Babilonia, ossia La caduta di Baldassare (Cyrus in Babylon, or The Downfall of Belshazzar) is an azione sacra in two acts by Gioachino Rossini with a libretto by Francesco Aventi.  It was first performed at the Teatro Comunale, Ferrara during Lent, 1812.  The exact date of the premiere is unknown but is believed to be 14 March.  During Lent it was the custom for Italian opera houses either to close or to stage works on themes from the Bible.  "Ciro in Babilonia" is one of two Lenten operas by Rossini (along with "Mosè in Egitto") and is based on the Biblical story of the overthrow of the Babylonian king Belshazzar by the Persian ruler Cyrus the Great. Zelmira (] ) is an opera in two acts by Gioachino Rossini to a libretto by Andrea Leone Tottola.  Based on the French play, "Zelmire" by de Belloy, it was the last of the composer's Neapolitan operas.  Stendhal called its music Teutonic, comparing it with "La clemenza di Tito" but remarking: "...while Mozart would probably, had he lived, have grown completely Italian, Rossini may well, by the end of his career, have become more German than Beethoven himself!"
Answer: Giovanni Gherardini