# Library of functions shared by all CI scripts

skip_branch_tip_with_tag () {
        # Sometimes, a branch is pushed at the same time the tag that points
        # at the same commit as the tip of the branch is pushed, and building
        # both at the same time is a waste.
        #
        # Travis gives a tagname e.g. v2.14.0 in $TRAVIS_BRANCH when
        # the build is triggered by a push to a tag.  Let's see if
        # $TRAVIS_BRANCH is exactly at a tag, and if so, if it is
        # different from $TRAVIS_BRANCH.  That way, we can tell if
        # we are building the tip of a branch that is tagged and
        # we can skip the build because we won't be skipping a build
        # of a tag.

        if TAG=$(git describe --exact-match "$TRAVIS_BRANCH" 2>/dev/null) &&
                test "$TAG" != "$TRAVIS_BRANCH"
        then
                echo "Tip of $TRAVIS_BRANCH is exactly at $TAG"
                exit 0
        fi
}

# Set 'exit on error' for all CI scripts to let the caller know that
# something went wrong
set -e

skip_branch_tip_with_tag