upstream_rename.sh

#!/bin/sh

set -e

# Prints all the git branch --set-upstream-to= commands that must be run
# after a remote changed the name of one of its branches.

# set -x

# default values, use environement to override
: "${REMOTE_URL:=https://github.com/zephyrproject-rtos/zephyr}"
: "${old_branch_name:=master}"
: "${new_branch_name:=main}"


main()
(
    # shellcheck disable=SC2039
    local rem rem_url brnch br_rem tracked_branch

    # Assumes people don't use whitespace in their remote names (otherwise
    # should do a bash while .. done <(git remote)
    for rem in $(git remote); do
        rem_url=$(git config --get remote."$rem".url)

        test "$rem_url" = ${REMOTE_URL} ||
            test "$rem_url" = ${REMOTE_URL}.git ||
            continue

        printf 'Found remote: %s %s\n' "$rem" "$rem_url"

        # no whitespace either, see above
        for brnch in $(git branch); do

            br_rem=$(git config --get branch."$brnch".remote) || true
            test "$br_rem" = "$rem" ||
                continue

            tracked_branch=$(git config --get branch."$brnch".merge) || true
            test "$tracked_branch" = refs/heads/"$old_branch_name" ||
                continue

            printf 'Please run:\n\tgit branch --set-upstream-to=%s %s\n' \
                   "$rem/$new_branch_name" "$brnch"

        done
    done
)

main "$@"