Of course. Here is the link. Please see page 15. The manual covers all "modern" revolvers that S&W makes, but this lock was added only after 2001. I have this lock, that's why I knew about it. The S&W Web site doesn't talk about it, and not even one photo exists that shows the gun from the other side (where the latch is.) You have to read the manual to see the lock.
I hadn’t realized that sort of thing had been added to revolvers; clearly I haven’t looked closely at modern revolvers in the last decade, if this has become common/routine.
Still, I don’t think this feature bears on the issue of self-defense carry safety. And the fact remains that people managed to carry loaded revolvers safely for many decades, and still do today, and many people manage to carry loaded Glocks in Condition One safely, some for a couple decades already, without a button safety. A button safety is simply not a be-all end-all to safe carry. And that is what this issue/discussion boils down to.
Asserting that Glocks are inherently unsafe to carry in Condition One is simply absurd, and this is what several have done here, including you. They are quite similar to revolvers when it comes to carry safety and handling. Hundreds of thousands, millions even, of people carry loaded revolvers and Condition One Glocks successfully. Now, if you feel unsafe with carrying Glocks, or loaded revolvers, that’s fine. But don’t try to shift blame for your fears and limitations onto what is a perfectly functional piece of hardware that serves many quite well.