Azure DevOps: platformAutomerge merge commit message is not updated when the PR title changes

[riksmithns]

How are you running Renovate?

Self-hosted Renovate CLI

Which platform you running Renovate on?

Other (please specify)

Which version of Renovate are you using?

44.146.3

Please tell us more about your question or problem

Platform: Azure DevOps

With automerge: true and platformAutomerge: true on Azure DevOps, Renovate enables auto-complete on its PRs and sets completionOptions.mergeCommitMessage to the PR title. When the PR title changes later, the merge commit message is not updated, so the PR auto-completes with an outdated commit message.

This happens in any run where Renovate pushes a new commit to the branch and the PR title changes, for example:

• Renovate updates the title itself: e.g. a PR Update dependency foo to v1.2.3 gets more updates and becomes Update all non-major dependencies, or a newer version becomes available (... to v1.2.4). The squash commit still uses the old title.
• A user requests a rebase by renaming the PR to rebase!<title>. Renovate rebases and restores the title, but the squash commit is named rebase!<title>.

Cause

1. In lib/workers/repository/update/branch/index.ts, after a new commit is pushed (commitSha), platform.reattemptPlatformAutomerge() is called. This happens before ensurePr().
2. In lib/modules/platform/azure/index.ts, reattemptPlatformAutomerge() → setPlatformAutomerge() re-reads the PR and sets mergeCommitMessage: pr.title, which is still the old title.
3. ensurePr() → updatePr() then sets the new title ({ title, description, ... }) but does not touch completionOptions.mergeCommitMessage, so the stale message is kept.

Possible fixes:

• Let updatePr() in the Azure platform also set completionOptions.mergeCommitMessage to the new title when auto-complete is enabled. Updating only completionOptions via the REST API (without autoCompleteSetBy) works and keeps the existing auto-complete owner.
• Or reattempt platform automerge after ensurePr() has updated the title.

Minimal reproduction

Setup: Azure DevOps repo with squash merge strategy and a branch policy (so the PR doesn't complete immediately), and this config:

{
  "automerge": true,
  "platformAutomerge": true
}

Scenario A (title changed by Renovate):

1. Let Renovate create a PR for a single update, e.g. Update dependency foo to v1.2.3. Auto-complete is set with merge commit message = PR title.
2. Wait until another update ends up in the same branch (e.g. a grouped PR gets a second dependency, or a newer version is released), and run Renovate.
3. The branch and the PR title are updated, but completionOptions.mergeCommitMessage (via the API) still has the old title.
4. Once policies pass, the PR auto-completes with the old title as the squash commit message.

Scenario B (rebase requested):

1. Rename a Renovate PR with auto-complete to rebase!<original title>.
2. Run Renovate: the branch is rebased and the title is restored.
3. completionOptions.mergeCommitMessage is rebase!<original title>, and the squash commit message on the base branch starts with rebase!.

Expected behavior

The merge commit message always matches the current PR title.

Logs (if relevant)

Logs

Replace this text with your logs, between the starting and ending triple backticks

[riksmithns]

This discussion seems "invisble" / "hidden" on Github. Seeing if a comment resurfaces it. (Result: It does, discussion is now visible)