Bruce Jenner -- Sad Sack in Calabasas

Bruce Jenner looked mighty unhappy Wednesday ... after "In Touch" ran a cover story with a Photoshopped pic and a caption touting his life as a woman.

Jenner was tooling around Calabasas, smoking a cig, as he pondered whatever was on his mind.

Our Bruce sources tell us he doesn't care what the tabloids say about him, but it must have been hard to avoid seeing the cover.

As for Kris, she says the magazine was mean, whether or not its story had any foothold on the truth.