Sharon Tate's sister, Debra Tate, has had a change of heart over Quentin Tarantino's upcoming flick about the Manson Family ... after a face-to-face with the director.

Debra tells TMZ ... Quentin reached out to her to break the ice and address her concerns over his project -- "Once Upon a Time in Hollywood" -- and was able to arrange a meeting recently.

Debra says she voiced her concerns and he heard her out, then explained the movie's plot ... which made her feel much better. She says she now believes Tarantino has honorable intentions ... "This movie is not what people would expect it to be when you combine the Tarantino and Manson names."

Debra's also pleased with the movie's new release date, which was bumped up 2 weeks in 2019 so it no longer coincides with the 50th anniversary of the murders ... which she thought was "tacky and exploitative."

She still has reservations, though ... but says she's going to meet with Quentin again to read the script and hash it out. But, she's on board for now ... even enough to see the flick.

The film stars Margot Robbie, Leo DiCaprio and Brad Pitt and is about a TV actor and his stunt double trying to make a name for themselves in Hollywood. Tarantino has publicly called it a movie about 1969, not just Charles Manson.

Quentin Tarantino has found his Bruce Lee for “Once Upon a Time in Hollywood,” TheWrap has learned. Mike Moh, who has repeatedly paid tribute to Lee online, will play the kung-fu master in Tarantino’s film set in the era of the Manson murders.

Moh was named as a member of the cast last month, but his role was not officially released. Individuals with knowledge of the project told to TheWrap this week that Moh will play Lee. That’s fitting, because Moh has honored Lee in YouTube videos (see below) and a tweet last month on the 45th anniversary of Lee’s death.

“It’s been 45 years since this man passed,” tweeted Moh, who is best known for playing Triton on Marvel’s “The Inhumans.” “#brucelee has inspired me in so many ways… Martial arts, acting, his philosophies on life. But look at the loving way he looked at his children. I know the exact feeling he felt RIP Bruce. Walk on”

The question of who would play Lee has interested his fans since news broke that Lee would appear in the film — though his appearance is likely to be brief.

For a brief time after the murders of his pregnant wife, Sharon Tate, and some of their closest friends, director Roman Polanski very wrongly believed that Bruce Lee may have killed them.

Moh’s hiring also adds racial diversity to a film packed with white actors. The story of the Manson murders is largely one of white killers and white victims — though the film will not focus strictly on the Manson family crimes. Brad Pitt and Leonardo DiCaprio, who will play the neighbors of Sharon Tate (Margot Robbie), are fictional characters.

Tarantino and Moh will likely have a lot of Lee love to discuss, as Lee’s influence on the filmmaker can’t be overstated.

For example, the yellow suit he wore to battle Kareem Abdul Jabbar in “Game of Death” inspired the one Uma Thurman’s Beatrix Kiddo (aka The Bride) wore as she took out the Crazy 88, Gogo Yubari and O-Ren in “Kill Bill Vol. 1.” As Polly told us on the podcast, Lee picked up the yellow suit during a trip with Polanski to Gstaad, Switzerland.

Moh’s hiring also adds racial diversity to a film packed with white actors. The story of the Manson murders is largely one of white killers and white victims — though the film will not focus strictly on the Manson family crimes.

Lena Dunham, Austin Butler, Maya Hawke, and Lorenza Izzo have joined the cast of Quentin Tarantino’s “Once Upon a Time in Hollywood.”

The movie is set against the backdrop of the Manson Family murders with Leonardo DiCaprio playing Rick Dalton, former star of a western TV series, while Brad Pitt will play his longtime stunt double, Cliff Booth. The studio announced a month ago that it was moving the release forward two weeks to July 26, 2019 — possibly avoiding controversy over the timing of the opening.

Dunham will be playing a character named Gypsy. Hawke has been cast as the fictional character Flower Child and Izzo will portray Francesca Capucci, a glamorous Italian movie star.