Git

Undo last commit and KEEP changes

git reset --soft HEAD~1

Undo last commit and LOSE changes

git reset --hard HEAD~1

List all remote branches

git ls-remote --heads <remote-name>

where remote-name is usually something like origin

Checkout remote branch and set it up for tracking

Note: These instructions are specific to having cloned in this manner: git clone -b <branch-name> --single-branch as it only tracks the branch chosen at clone time.

git fetch origin <branch-name>

git remote set-branches origin <branch-name>

Show contents of merge commit

git show -m [SHA1]

where -m means maximum verbosity, automatically implied only with non-merge commits