Add branch support to ChangeLog helper tool

[pljones]

Short description of changes

I made this change when working on the release 3.12.3 changes because there were multiple fixes in the release.

As written, the tool had main hard coded. This change now makes main the default branch but allows an alternative branch to be specified -- e.g. --branch release/3_12.

Tested - it no longer finds merges to main that didn't get to release/3_12.

CHANGELOG: SKIP

Context: Fixes an issue?

Release process helper update.

Does this change need documentation? What needs to be documented and how?

No. (--help updated)

Status of this Pull Request

Test on Release 3.12.3 ChangeLog.

What is missing until this pull request can be merged?

Should be okay to merge.

Checklist

• I've verified that this Pull Request follows the general code principles
• I tested my code and it does what I want
• My code follows the style guide
• I waited some time after this Pull Request was opened and all GitHub checks completed without errors.
• I've filled all the content above

[Copilot]

Pull request overview

This PR updates the tools/changelog-helper.sh release-process helper to support checking PR references against a specified branch instead of always using main, enabling accurate ChangeLog verification for release branches (e.g. release/3_12).

Changes:

• Add a --branch CLI option (defaulting to main) to select which branch to check.
• Pass the selected branch through to the “find/add missing entries” flow and update --help output accordingly.
• Adjust git ref handling in the missing-entry scan to incorporate the selected branch.

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[Copilot]

Pull request overview

Copilot reviewed 1 out of 1 changed files in this pull request and generated 1 comment.

Comments suppressed due to low confidence (1)

tools/changelog-helper.sh:104

• target_ref is computed (and even switched to the release tag when it exists), but the subsequent git log still uses ${branch}. This means the selected ref/tag is ignored and the output can be wrong for released versions or when the target branch only exists as origin/<branch>. Also the "Ignoring PR" message still refers to ..HEAD instead of the actual range being scanned.

    echo
    echo "Checking if all PR references in git log since ${prev_release_tag} are included for ${target_release} based on ref ${target_ref}..."
    local milestone
    for id in $(git log "${prev_release_tag}..${branch}" | grep -oP '#\K(\d+)'); do
        gh pr view "${id}" --json title &> /dev/null || continue # Skip non-PRs

[softins]

Apart from those comments, this looks sensible and in line with the existing design of the script.

[Copilot]

Pull request overview

Copilot reviewed 1 out of 1 changed files in this pull request and generated no new comments.