sync: Add failing test scripts for branch sync feature

.changes/unreleased/Added-20260610-211549.yaml

@@ -0,0 +1,3 @@
+kind: Added
+body: 'sync: Add `gs branch sync` (and `gs stack sync` / `gs upstack sync` / `gs downstack sync`) to pull remote-side commits added to a tracked branch since the last push. Default behavior is fast-forward only; use `--rebase` (or `spice.repoSync.pullBranches=rebase`) to integrate remote-side commits even when the branch has been restacked since its last push. A branch that has only moved locally, with no new remote commits, is reported as owing a push rather than as diverged.'
+time: 2026-06-10T21:15:49.107419-04:00

.changes/unreleased/Added-20260610-211604.yaml

@@ -0,0 +1,3 @@
+kind: Added
+body: 'submit: Record the pushed commit hash for each tracked branch as `LastPushedHash` so subsequent syncs can distinguish bot-added commits from divergence.'
+time: 2026-06-10T21:16:04.581853-04:00

.changes/unreleased/Changed-20260610-211549.yaml

@@ -0,0 +1,3 @@
+kind: Changed
+body: 'repo sync: After the trunk pull, also pull remote-side commits on tracked stack branches via the new `spice.repoSync.pullBranches` config (default `fastForward`). Closes the common loop where CI bots add a commit and the next `gs submit` is rejected with "stale info".'
+time: 2026-06-10T21:15:49.138568-04:00

.changes/unreleased/Fixed-20260610-211549.yaml

@@ -0,0 +1,3 @@
+kind: Fixed
+body: 'test/shamhub: Pass `--git-dir` to git invocations against bare repos so shamhub-backed tests work on git 2.50+ (which no longer auto-discovers a bare repo from cwd alone).'
+time: 2026-06-10T21:15:49.166884-04:00

branch.go

@@ -38,6 +38,7 @@ type branchCmd struct {
 	// Pull request management
 	Merge  branchMergeCmd  `cmd:"" aliases:"m" experiment:"merge" help:"Merge a branch into trunk"`
 	Submit branchSubmitCmd `cmd:"" aliases:"s" help:"Submit a branch"`
+	Sync   branchSyncCmd   `cmd:"" aliases:"sy" help:"Pull remote-side commits into a tracked branch" released:"unreleased"`
 }
 
 // BranchPromptConfig defines configuration for the branch tree prompt

branch_sync.go

@@ -0,0 +1,75 @@
+package main
+
+import (
+	"context"
+	"fmt"
+
+	"go.abhg.dev/gs/internal/git"
+	"go.abhg.dev/gs/internal/handler/branchsync"
+	"go.abhg.dev/gs/internal/silog"
+	"go.abhg.dev/gs/internal/text"
+)
+
+type branchSyncCmd struct {
+	Branch string `placeholder:"NAME" help:"Branch to sync" predictor:"trackedBranches"`
+	Rebase bool   `help:"On divergence (both local and remote have new commits since the last push), replay remote-side commits onto local. Conflicts surface as a normal interrupted rebase; resume with 'gs rebase --continue'."`
+}
+
+func (*branchSyncCmd) Help() string {
+	return text.Dedent(`
+		Pull remote-side commits added to a tracked branch since the
+		last push (typically by a CI bot like autofix-ci).
+
+		The branch is fast-forwarded only if local has no commits past
+		the last push and the remote has moved forward. Diverged
+		branches (both sides have new commits) are reported and left
+		unchanged in this release; use 'gs upstack restack' after
+		moving the parent if you need to integrate them manually.
+
+		Children of a fast-forwarded branch will need a restack;
+		'gs upstack restack' from this branch will pick that up.
+	`)
+}
+
+func (cmd *branchSyncCmd) AfterApply(ctx context.Context, wt *git.Worktree) error {
+	if cmd.Branch == "" {
+		currentBranch, err := wt.CurrentBranch(ctx)
+		if err != nil {
+			return fmt.Errorf("get current branch: %w", err)
+		}
+		cmd.Branch = currentBranch
+	}
+	return nil
+}
+
+func (cmd *branchSyncCmd) Run(
+	ctx context.Context,
+	log *silog.Logger,
+	handler *branchsync.Handler,
+) error {
+	req := branchsync.SyncRequest{Branch: cmd.Branch}
+	if cmd.Rebase {
+		req.Mode = branchsync.ModeRebase
+	}
+	res, err := handler.Sync(ctx, req)
+	if err != nil {
+		return err
+	}
+
+	switch res.Action {
+	case branchsync.ActionClean:
+		log.Infof("%v: already in sync", res.Branch)
+	case branchsync.ActionFastForward:
+		log.Infof("%v: fast-forwarded %s..%s", res.Branch, res.FromHash.Short(), res.ToHash.Short())
+	case branchsync.ActionRebased:
+		log.Infof("%v: rebased onto remote %s", res.Branch, res.ToHash.Short())
+	case branchsync.ActionBehind:
+		log.Infof("%v: ahead of remote; nothing to pull", res.Branch)
+	case branchsync.ActionDiverged:
+		log.Warnf("%v: diverged from remote; pass --rebase to integrate remote-side commits", res.Branch)
+	case branchsync.ActionSkipped:
+		log.Warnf("%v: skipped (%v)", res.Branch, res.SkipReason)
+	}
+
+	return nil
+}

doc/includes/cli-reference.md

@@ -162,11 +162,19 @@ Run with --restack to also restack them and their upstacks.
 Run with --restack=aboves to only restack direct upstacks
 of deleted branches, leaving higher branches in place.
 
+After the trunk sync, every other tracked branch is also
+checked against its remote: if the remote has new commits
+(typically from a CI bot) and local has not moved past the
+last-pushed hash, the local branch is fast-forwarded so the
+next 'gs submit' will not be rejected with "stale info".
+Pass --no-pull-branches to skip this step.
+
 **Flags**
 
 * `--restack` ([:material-wrench:{ .middle title="spice.repoSync.restack" }](/cli/config.md#spicereposyncrestack)): How to restack branches above deleted branches. One of 'none', 'aboves', and 'upstack'.
+* `--pull-branches="fastForward"` ([:material-wrench:{ .middle title="spice.repoSync.pullBranches" }](/cli/config.md#spicereposyncpullbranches)): How to integrate remote-side commits on tracked stack branches. 'off' skips the per-branch pull; 'fastForward' (default) advances safe branches and skips diverged ones; 'rebase' replays diverged branches' local commits on top of the remote.
 
-**Configuration**: [spice.repoSync.closedChanges](/cli/config.md#spicereposyncclosedchanges), [spice.repoSync.restack](/cli/config.md#spicereposyncrestack)
+**Configuration**: [spice.repoSync.closedChanges](/cli/config.md#spicereposyncclosedchanges), [spice.repoSync.pullBranches](/cli/config.md#spicereposyncpullbranches), [spice.repoSync.restack](/cli/config.md#spicereposyncrestack)
 
 ### git-spice repo restack {#gs-repo-restack}
 
@@ -330,6 +338,25 @@ Use --fail-fast to stop the queue after the first branch failure.
 
 **Configuration**: [spice.merge.method](/cli/config.md#spicemergemethod), [spice.merge.readyTimeout](/cli/config.md#spicemergereadytimeout)
 
+### git-spice stack sync {#gs-stack-sync}
+
+```
+gs stack (s) sync (sy) [flags]
+```
+
+<span class="mdx-badge"><span class="mdx-badge__icon">:material-tag-hidden:{ title="Released in version" }</span><span class="mdx-badge__text">Unreleased</span></span>
+
+Pull remote-side commits for every branch in the stack
+
+Pull remote-side commits for every branch in the current
+stack (downstack and upstack of the named branch), bottom-up.
+Use --branch to identify a different stack.
+
+**Flags**
+
+* `--branch=NAME`: Branch to identify the stack
+* `--rebase`: On divergence, replay remote-side commits onto local.
+
 ### git-spice stack restack {#gs-stack-restack}
 
 ```
@@ -453,6 +480,27 @@ only if there are multiple CRs in the stack.
 
 **Configuration**: [spice.submit.assignees](/cli/config.md#spicesubmitassignees), [spice.submit.draft](/cli/config.md#spicesubmitdraft), [spice.submit.labels](/cli/config.md#spicesubmitlabels), [spice.submit.labels.addWhen](/cli/config.md#spicesubmitlabelsaddwhen), [spice.submit.listTemplatesTimeout](/cli/config.md#spicesubmitlisttemplatestimeout), [spice.submit.navigationComment](/cli/config.md#spicesubmitnavigationcomment), [spice.submit.navigationComment.downstack](/cli/config.md#spicesubmitnavigationcommentdownstack), [spice.submit.navigationCommentStyle.marker](/cli/config.md#spicesubmitnavigationcommentstylemarker), [spice.submit.navigationCommentSync](/cli/config.md#spicesubmitnavigationcommentsync), [spice.submit.publish](/cli/config.md#spicesubmitpublish), [spice.submit.reviewers](/cli/config.md#spicesubmitreviewers), [spice.submit.reviewers.addWhen](/cli/config.md#spicesubmitreviewersaddwhen), [spice.submit.skipRestackCheck](/cli/config.md#spicesubmitskiprestackcheck), [spice.submit.template](/cli/config.md#spicesubmittemplate), [spice.submit.updateOnly](/cli/config.md#spicesubmitupdateonly), [spice.submit.web](/cli/config.md#spicesubmitweb)
 
+### git-spice upstack sync {#gs-upstack-sync}
+
+```
+gs upstack (us) sync (sy) [flags]
+```
+
+<span class="mdx-badge"><span class="mdx-badge__icon">:material-tag-hidden:{ title="Released in version" }</span><span class="mdx-badge__text">Unreleased</span></span>
+
+Pull remote-side commits for a branch and those above it
+
+Pull remote-side commits for the current branch and all
+branches upstack from it. Branches that fast-forward
+(or rebase, with --rebase) trigger an upstack restack of
+their children so the stack stays coherent.
+Use --branch to start at a different branch.
+
+**Flags**
+
+* `--branch=NAME`: Branch to start at
+* `--rebase`: On divergence, replay remote-side commits onto local.
+
 ### git-spice upstack restack {#gs-upstack-restack}
 
 ```
@@ -608,6 +656,25 @@ only if there are multiple CRs in the stack.
 
 **Configuration**: [spice.submit.assignees](/cli/config.md#spicesubmitassignees), [spice.submit.draft](/cli/config.md#spicesubmitdraft), [spice.submit.labels](/cli/config.md#spicesubmitlabels), [spice.submit.labels.addWhen](/cli/config.md#spicesubmitlabelsaddwhen), [spice.submit.listTemplatesTimeout](/cli/config.md#spicesubmitlisttemplatestimeout), [spice.submit.navigationComment](/cli/config.md#spicesubmitnavigationcomment), [spice.submit.navigationComment.downstack](/cli/config.md#spicesubmitnavigationcommentdownstack), [spice.submit.navigationCommentStyle.marker](/cli/config.md#spicesubmitnavigationcommentstylemarker), [spice.submit.navigationCommentSync](/cli/config.md#spicesubmitnavigationcommentsync), [spice.submit.publish](/cli/config.md#spicesubmitpublish), [spice.submit.reviewers](/cli/config.md#spicesubmitreviewers), [spice.submit.reviewers.addWhen](/cli/config.md#spicesubmitreviewersaddwhen), [spice.submit.skipRestackCheck](/cli/config.md#spicesubmitskiprestackcheck), [spice.submit.template](/cli/config.md#spicesubmittemplate), [spice.submit.updateOnly](/cli/config.md#spicesubmitupdateonly), [spice.submit.web](/cli/config.md#spicesubmitweb)
 
+### git-spice downstack sync {#gs-downstack-sync}
+
+```
+gs downstack (ds) sync (sy) [flags]
+```
+
+<span class="mdx-badge"><span class="mdx-badge__icon">:material-tag-hidden:{ title="Released in version" }</span><span class="mdx-badge__text">Unreleased</span></span>
+
+Pull remote-side commits for a branch and those below it
+
+Pull remote-side commits for the current branch and all
+branches downstack from it (excluding trunk).
+Use --branch to start at a different branch.
+
+**Flags**
+
+* `--branch=NAME`: Branch to start at
+* `--rebase`: On divergence, replay remote-side commits onto local.
+
 ### git-spice downstack merge {#gs-downstack-merge}
 
 ```
@@ -1205,6 +1272,33 @@ only if there are multiple CRs in the stack.
 
 **Configuration**: [spice.submit.assignees](/cli/config.md#spicesubmitassignees), [spice.submit.draft](/cli/config.md#spicesubmitdraft), [spice.submit.labels](/cli/config.md#spicesubmitlabels), [spice.submit.labels.addWhen](/cli/config.md#spicesubmitlabelsaddwhen), [spice.submit.listTemplatesTimeout](/cli/config.md#spicesubmitlisttemplatestimeout), [spice.submit.navigationComment](/cli/config.md#spicesubmitnavigationcomment), [spice.submit.navigationComment.downstack](/cli/config.md#spicesubmitnavigationcommentdownstack), [spice.submit.navigationCommentStyle.marker](/cli/config.md#spicesubmitnavigationcommentstylemarker), [spice.submit.navigationCommentSync](/cli/config.md#spicesubmitnavigationcommentsync), [spice.submit.publish](/cli/config.md#spicesubmitpublish), [spice.submit.reviewers](/cli/config.md#spicesubmitreviewers), [spice.submit.reviewers.addWhen](/cli/config.md#spicesubmitreviewersaddwhen), [spice.submit.skipRestackCheck](/cli/config.md#spicesubmitskiprestackcheck), [spice.submit.template](/cli/config.md#spicesubmittemplate), [spice.submit.web](/cli/config.md#spicesubmitweb)
 
+### git-spice branch sync {#gs-branch-sync}
+
+```
+gs branch (b) sync (sy) [flags]
+```
+
+<span class="mdx-badge"><span class="mdx-badge__icon">:material-tag-hidden:{ title="Released in version" }</span><span class="mdx-badge__text">Unreleased</span></span>
+
+Pull remote-side commits into a tracked branch
+
+Pull remote-side commits added to a tracked branch since the
+last push (typically by a CI bot like autofix-ci).
+
+The branch is fast-forwarded only if local has no commits past
+the last push and the remote has moved forward. Diverged
+branches (both sides have new commits) are reported and left
+unchanged in this release; use 'gs upstack restack' after
+moving the parent if you need to integrate them manually.
+
+Children of a fast-forwarded branch will need a restack;
+'gs upstack restack' from this branch will pick that up.
+
+**Flags**
+
+* `--branch=NAME`: Branch to sync
+* `--rebase`: On divergence (both local and remote have new commits since the last push), replay remote-side commits onto local. Conflicts surface as a normal interrupted rebase; resume with 'gs rebase --continue'.
+
 ## Commit
 
 ### git-spice commit create {#gs-commit-create}

doc/includes/cli-shorthands.md

@@ -13,6 +13,7 @@
 | gs bs | [gs branch submit](/cli/reference.md#gs-branch-submit) |
 | gs bsp | [gs branch split](/cli/reference.md#gs-branch-split) |
 | gs bsq | [gs branch squash](/cli/reference.md#gs-branch-squash) |
+| gs bsy | [gs branch sync](/cli/reference.md#gs-branch-sync) |
 | gs btr | [gs branch track](/cli/reference.md#gs-branch-track) |
 | gs buntr | [gs branch untrack](/cli/reference.md#gs-branch-untrack) |
 | gs ca | [gs commit amend](/cli/reference.md#gs-commit-amend) |
@@ -24,6 +25,7 @@
 | gs dsm | [gs downstack merge](/cli/reference.md#gs-downstack-merge) |
 | gs dsr | [gs downstack restack](/cli/reference.md#gs-downstack-restack) |
 | gs dss | [gs downstack submit](/cli/reference.md#gs-downstack-submit) |
+| gs dssy | [gs downstack sync](/cli/reference.md#gs-downstack-sync) |
 | gs dstr | [gs downstack track](/cli/reference.md#gs-downstack-track) |
 | gs ll | [gs log long](/cli/reference.md#gs-log-long) |
 | gs ls | [gs log short](/cli/reference.md#gs-log-short) |
@@ -37,7 +39,9 @@
 | gs sm | [gs stack merge](/cli/reference.md#gs-stack-merge) |
 | gs sr | [gs stack restack](/cli/reference.md#gs-stack-restack) |
 | gs ss | [gs stack submit](/cli/reference.md#gs-stack-submit) |
+| gs ssy | [gs stack sync](/cli/reference.md#gs-stack-sync) |
 | gs usd | [gs upstack delete](/cli/reference.md#gs-upstack-delete) |
 | gs uso | [gs upstack onto](/cli/reference.md#gs-upstack-onto) |
 | gs usr | [gs upstack restack](/cli/reference.md#gs-upstack-restack) |
 | gs uss | [gs upstack submit](/cli/reference.md#gs-upstack-submit) |
+| gs ussy | [gs upstack sync](/cli/reference.md#gs-upstack-sync) |

doc/src/guide/cr.md

@@ -269,6 +269,46 @@ in one step, use the `--restack` flag:
 {green}${reset} gs repo sync --restack
 ```
 
+### Pulling remote-side commits on stack branches
+
+<!-- gs:version unreleased -->
+
+After the trunk pull and merged-branch handling,
+$$gs repo sync$$ also pulls remote-side commits added to each tracked
+stack branch since its last push --
+typically commits added by CI bots such as autofix-ci, license-headers,
+or codeowners.
+
+Branches that fast-forward bring their children along by triggering an
+upstack restack.
+When the remote has genuinely gained commits but the local branch has
+also moved -- including branches restacked onto a newer trunk since
+their last push -- the branch is reported as diverged and skipped by
+default.
+A branch that has only moved locally, with no new remote commits,
+is recognized as simply owing a push and is not reported as diverged.
+To replay the remote-side commits on top of a diverged branch
+(even one that has been restacked), set:
+
+```freeze language="terminal"
+{green}${reset} git config {red}spice.repoSync.pullBranches{reset} {mag}rebase{reset}
+```
+
+To skip the per-branch pull entirely,
+set the value to `off`.
+See the [configuration reference](../cli/config.md#spicereposyncpullbranches).
+
+For finer-grained control,
+the same machinery is also available per branch and per scope:
+
+```freeze language="terminal"
+{green}${reset} gs branch sync           {gray}# current branch only{reset}
+{green}${reset} gs upstack sync          {gray}# current branch and above{reset}
+{green}${reset} gs downstack sync        {gray}# current branch and below{reset}
+{green}${reset} gs stack sync            {gray}# the whole stack{reset}
+{green}${reset} gs branch sync --rebase  {gray}# integrate a diverged branch{reset}
+```
+
 ### Handling closed Change Requests
 
 When running $$gs repo sync$$, if a Change Request was closed

downstack.go

@@ -3,6 +3,7 @@ package main
 type downstackCmd struct {
 	Track   downstackTrackCmd   `cmd:"" aliases:"tr" help:"Track all untracked branches below a branch"`
 	Submit  downstackSubmitCmd  `cmd:"" aliases:"s" help:"Submit a branch and those below it"`
+	Sync    downstackSyncCmd    `cmd:"" aliases:"sy" help:"Pull remote-side commits for a branch and those below it" released:"unreleased"`
 	Merge   downstackMergeCmd   `cmd:"" aliases:"m" experiment:"merge" help:"Merge a branch and those below it"`
 	Edit    downstackEditCmd    `cmd:"" aliases:"e" help:"Edit the order of branches below a branch"`
 	Restack downstackRestackCmd `cmd:"" aliases:"r" help:"Restack a branch and its downstack"`

downstack_sync.go

@@ -0,0 +1,60 @@
+package main
+
+import (
+	"context"
+	"fmt"
+	"slices"
+
+	"go.abhg.dev/gs/internal/git"
+	"go.abhg.dev/gs/internal/handler/branchsync"
+	"go.abhg.dev/gs/internal/silog"
+	"go.abhg.dev/gs/internal/spice"
+	"go.abhg.dev/gs/internal/spice/state"
+	"go.abhg.dev/gs/internal/text"
+)
+
+type downstackSyncCmd struct {
+	Branch string `placeholder:"NAME" help:"Branch to start at" predictor:"trackedBranches"`
+	Rebase bool   `help:"On divergence, replay remote-side commits onto local."`
+}
+
+func (*downstackSyncCmd) Help() string {
+	return text.Dedent(`
+		Pull remote-side commits for the current branch and all
+		branches downstack from it (excluding trunk).
+		Use --branch to start at a different branch.
+	`)
+}
+
+func (cmd *downstackSyncCmd) Run(
+	ctx context.Context,
+	log *silog.Logger,
+	wt *git.Worktree,
+	store *state.Store,
+	svc *spice.Service,
+	branchSyncHandler *branchsync.Handler,
+	restackHandler RestackHandler,
+) error {
+	if cmd.Branch == "" {
+		currentBranch, err := wt.CurrentBranch(ctx)
+		if err != nil {
+			return fmt.Errorf("get current branch: %w", err)
+		}
+		cmd.Branch = currentBranch
+	}
+
+	graph, err := svc.BranchGraph(ctx, nil)
+	if err != nil {
+		return fmt.Errorf("build branch graph: %w", err)
+	}
+
+	branches := slices.Collect(graph.Downstack(cmd.Branch))
+	// Downstack is [branch, child1, child2, ..., trunk-adjacent]; we want
+	// to sync bottom-up so children pick up updated bases.
+	slices.Reverse(branches)
+	// Drop trunk if present.
+	trunk := store.Trunk()
+	branches = slices.DeleteFunc(branches, func(b string) bool { return b == trunk })
+
+	return syncBranches(ctx, log, branchSyncHandler, restackHandler, branches, cmd.Rebase)
+}