In commit 2596d157, we added a condition to run auto-backport.py only
when the GitHub Action is triggered by a push to the default branch.
However, this introduced an unexpected error due to incorrect condition
handling.
Problem:
- `github.event.before` evaluates to an empty string
- GitHub Actions' single-pass expression evaluation system causes
the step to always execute, regardless of `github.event_name`
Despite GitHub's documentation suggesting that ${{ }} can be omitted,
it recommends using explicit ${{}} expressions for compound conditions.
Changes:
- Use explicit ${{}} expression for compound conditions
- Avoid string interpolation in conditional statements
Root Cause:
The previous implementation failed because of how GitHub Actions
evaluates conditional expressions, leading to an unintended script
execution and a 404 error when attempting to compare commits.
Example Error:
```
python .github/scripts/auto-backport.py --repo scylladb/scylladb --base-branch refs/heads/master --commits ..2b07d93beac7bc83d955dadc20ccc307f13f20b6
shell: /usr/bin/bash -e {0}
env:
DEFAULT_BRANCH: master
GITHUB_TOKEN: ***
Traceback (most recent call last):
File "/home/runner/work/scylladb/scylladb/.github/scripts/auto-backport.py", line 201, in <module>
main()
File "/home/runner/work/scylladb/scylladb/.github/scripts/auto-backport.py", line 162, in main
commits = repo.compare(start_commit, end_commit).commits
File "/usr/lib/python3/dist-packages/github/Repository.py", line 888, in compare
headers, data = self._requester.requestJsonAndCheck(
File "/usr/lib/python3/dist-packages/github/Requester.py", line 353, in requestJsonAndCheck
return self.__check(
File "/usr/lib/python3/dist-packages/github/Requester.py", line 378, in __check
raise self.__createException(status, responseHeaders, output)
github.GithubException.UnknownObjectException: 404 {"message": "Not Found", "documentation_url": "https://docs.github.com/rest/commits/commits#compare-two-commits", "status": "404"}
```
Fixesscylladb/scylladb#21808
Signed-off-by: Kefu Chai <kefu.chai@scylladb.com>
Closesscylladb/scylladb#21809