Create a new plan and configure Gatekeeper with push enabled. Use a regex for automatic plan branching, e.g. /gatekeeper-/ so only branches containing "gatekeeper-" will be automatically created and set up with Gatekeeper.

Now, create a VCS branch whose name doesn't contain gatekeeper- e.g. "dangerous-do-not-merge." Go to the plan's branches page and click "Create Branch," select your branch, and click "Create."

On the branch configuration UI, you'll now have the option to set branch settings, e.g. to set up Branch Updater, or disable push, or even disable the branch build altogether while you configure other settings.

Actual: While you're reading that page, Bamboo will automatically kick off a Gatekeeper build of dangerous-do-not-merge, with push enabled. You have to quickly go in and kill the build before it commits those changes to the master branch.

Expected: An "Enable Branch" checkbox on the default "Create Branch" dialog.

Today, the Create Branch dialog has two modes, one to "Auto-detect VCS branches" (which is different from automatic plan branching; it's just auto-detecting and listing branches for you to manually create) and another to "Create branch manually." There's an "Enable Branch" checkbox in the "Create branch manually" mode, unchecked by default, but there isn't a corresponding checkbox in the "Auto-detect VCS branches" list mode. (Screenshots attached.)

That means that it's dangerous to use the "Auto-detect VCS branches" mode (the default) together with automatic plan branching and branch merging, because if you use it, it's going to immediately start checking in code unless you kill the build.