> If we push a branch and a tag pointing to the HEAD of this branch,
s/the HEAD of//, perhaps?
There is no such thing as "HEAD" (all capital!) of a branch, is it?
> then Travis CI would run the build twice. This wastes resources and
Nit: s/run the build/build and test the same tree/, to further stress
that the two builds are redundant.
> slows the testing.
>
> Add a function to detect this situation and skip the build the branch
s/skip the build/skip building/ ?
> if appropriate. Invoke this function on every build.
>
> Helped-by: Junio C Hamano <gitster@xxxxxxxxx>
> Signed-off-by: Lars Schneider <larsxschneider@xxxxxxxxx>
> ---
> ci/lib-travisci.sh | 23 +++++++++++++++++++++++
> 1 file changed, 23 insertions(+)
>
> diff --git a/ci/lib-travisci.sh b/ci/lib-travisci.sh
> index 44d6ba2dd2..9c4ae9bdd0 100755
> --- a/ci/lib-travisci.sh
> +++ b/ci/lib-travisci.sh
> @@ -1,5 +1,28 @@
> # 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) &&
> + $TAG != $TRAVIS_BRANCH
This must be
[ $TAG != $TRAVIS_BRANCH ]
otherwise the shell will rightfully complain:
$ TRAVIS_BRANCH=v2.14.0 ./ci/lib-travisci.sh
./ci/lib-travisci.sh: line 17: v2.14.0: command not found
Furthermore, I would prefer quotes around $TAG and $TRAVIS_BRANCH. If
either one of those two variables were empty (or contain multiple
words) at that point, the shell would complain. Now, I don't think
that either can end up being empty, so quotes are not necessary, but
having quotes around them would save future readers from spending
brain cycles on this unnecessarily.
> + 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
> --
> 2.14.1
>
>
