fast forward active branches where local is behind remote#40
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Pull request overview
Adds support for fast-forwarding stack branches that are locally behind their remote counterpart, so sync/rebase operate on up-to-date branch tips before cascading rebases.
Changes:
- Introduce a shared
fastForwardBrancheshelper to fast-forward active stack branches when local is strictly behindremote/<branch>. - Run branch fast-forwarding during
gh stack sync(and trigger cascade rebase when any branch moved) and duringgh stack rebase. - Update sync/rebase tests and mocks to model
origin/<branch>SHAs and cover branch fast-forward scenarios.
Show a summary per file
| File | Description |
|---|---|
| cmd/utils.go | Adds fastForwardBranches helper used by sync/rebase to fast-forward active branches behind the chosen remote. |
| cmd/sync.go | Calls fastForwardBranches and treats “any branch moved” as a reason to cascade rebase. |
| cmd/rebase.go | Calls fastForwardBranches before the cascade rebase begins. |
| cmd/sync_test.go | Adjusts mock SHA behavior and adds coverage for branch fast-forward-driven rebases/force pushes. |
| cmd/rebase_test.go | Adjusts mock SHA behavior and adds coverage for branch fast-forward behavior during rebase. |
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Lukeghenco
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Apr 16, 2026
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* fast forward active branches where local is behind remote
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Ports the still-applicable upstream changes since the fork point, adapted to this fork's standard-GitHub-API architecture (no private stack backend; stack deps tracked via "Requires #N"). Each change was test-driven. Bug fixes: - github#56 guard GraphQL PR-number conversion against int32 overflow - github#41 skip merged+deleted branches when rebasing (rev-parse error) - github#42 same fix on the sync path - github#43 --onto rebase for merged branches: backfill refs, pre-seed onto state, stale-base fallback via merge-base - github#39 always anchor branch diffs on the merge-base (inflated diff counts) - github#95 sync now cascades when the stack is stale even if trunk is current; rebase skips queued branches (IsSkipped) - github#80 view --json resolves directly with typed exit codes (no prompt) - github#49 (Part A) ignore stale merged/closed PRs for reused branch names (the backend ListStacks path is intentionally omitted) Features (standard API only): - github#108 trunk command - github#51 switch command - github#74 unstack -> active - github#101 add adopts existing branch - github#40 fast-forward branches behind their remote - github#76 draft PRs by default + --open (adds MarkPRReadyForReview) - github#77 seed PR body from repo template (keeps "Requires #N") - github#94 sync --prune merged branches Infra / cleanup: - github#103/github#110 bump github.com/cli/cli/v2 to v2.93.0 (go get + tidy) - github#89 remove placeholder `merge` command + docs - fix stale `unstack [branch]` docs Note: this commit is layered on in-progress local work (go-git ops, PR/commit caching, discover command) that shares the same files, so the two are committed together. Full suite green: build, vet, go test ./...
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Fast-forward stack branches that are behind their remote
In certain situations, when there was an upstream commit not present on local,
gh stack rebaseandgh stack syncwould rebase on top of the stale local ref, effectively dropping the new commits.Fix: Before the cascade rebase, both
rebaseandsyncnow detect stack branches where the local ref is strictly behind the remote tracking branch and fast-forward them. If the branch has diverged, it's left alone (the push step handles that). Forsync, a branch fast-forward also triggers the cascade rebase even if trunk hasn't moved.