DRONE_COMMIT_BRANCH refers to target, not source branch in merge requests

[based64god]

Type:
Bug report. I have a single drone instance running hooked up to a gitlab server via webhooks.

What happened:
Both https://docs.drone.io/reference/environ/drone-commit-branch/ and https://docs.drone.io/reference/environ/drone-branch/ refer to the target branch in builds triggered by merge requests.

Expected:
Both https://docs.drone.io/reference/environ/drone-commit-branch/ and https://docs.drone.io/reference/environ/drone-branch/ should refer to the source branch, while https://docs.drone.io/reference/environ/drone-target-branch/ should refer to the target.

I suspect this is a gitlab issue, and is probably not reproducible on github.

[bradrydzewski]

Hmmm, I am unable to reproduce this issue (drone 1.0.0-rc.5). The mapping of source and target branch for merge request for GitLab can be found here:
https://github.com/drone/go-scm/blob/master/scm/driver/gitlab/webhook.go#L244:L245

[based64god]

Here's a screenshot of the build log. I don't see this for builds triggered by pushes. It's only for ones triggered by merge events. Are there any logs I can push up here that might be useful?

[based64god]

Small update.

Appears to be working as intended.

[based64god]

For anyone who finds this in the future, you want DRONE_SOURCE_BRANCH.

[quantonganh]

@bradrydzewski So, we agree that DRONE_COMMIT_BRANCH should refer to source branch (as in 0.8), right?

https://github.com/drone/drone/blob/2a3ffc779ba33a9d9c14ec4faae4cbaac0d898ad/operator/runner/env.go#L85

[bradrydzewski]

nope, DRONE_COMMIT_BRANCH has always been the target branch, including in 0.8. In 1.0 we also provide more explicit values DRONE_SOURCE_BRANCH and DRONE_TARGET_BRANCH

[quantonganh]

DRONE_COMMIT_BRANCH has always been the target branch, including in 0.8

I don't think so: https://github.com/drone/drone/blob/768ed784bd74b0e0c2d8d49c4c8b6dca99b25e96/remote/gitlab/gitlab.go#L530

[bradrydzewski]

for GitHub and other providers it was target branch. If GitLab were using source branch previously it was a bug. The 1.0 implementation is the desired state.

[quantonganh]

for GitHub and other providers it was target branch.

OK: https://github.com/drone/drone/blob/768ed784bd74b0e0c2d8d49c4c8b6dca99b25e96/remote/github/convert.go#L268

But IMO, it should be source branch, as target branch often is master.

The question is: Is there any env that we can use to refer to the source branch (for both push and pull_request events)?

[bradrydzewski]

yes, you can use DRONE_SOURCE_BRANCH for push and pull_request events.