fix(server): pushing a branch whose remote branch was deleted publishes it again - #29619

Eligibility
A push can republish a branch after its remote branch was deleted, while preserving comparison-base metadata. Existing remote overrides and ordinary non-force Git push protections remain in place.

Additional Thinking

Your Custom Policy

Applied the default criteria. This repairs deleted-upstream handling rather than changing a product default, and the assessed diff adds no static-analysis suppression directives; neither additional human-review condition applies.

Code

Treats a deleted upstream ref as absent and lets a subsequent push republish the branch using retained Git configuration. Explicit push-remote settings retain precedence; differently named base upstreams are preserved before retargeting. Remote writes remain ordinary, non-force Git pushes. Shared status reporting also reflects the missing upstream. The customer-ignored file was not reconstructed.

Review Context

The author is saphid; no ownership information or check results were supplied. Four review threads were reported resolved, with no unresolved comments or correctness findings supplied.

Verdict

The change is confined to handling missing upstreams during existing Git status and push operations. Publishing follows the push request, respects configured remote overrides, avoids force updates, and preserves comparison-base configuration. No obvious material risk requiring human judgment remains.

Notes:
No code owners found in target merge base 60aec28

Agent Credits: 30 credits
Approvability runs at a flat rate of 30 credits whenever the agent is asked for a verdict.