Default new worktrees to the upstream branch (#2848)

* fix(workspaces): default new worktrees to upstream refs

Use the daemon-resolved upstream as the untouched starting ref so unpushed local commits do not leak into new workspaces. Preserve exact base identity for fork remotes while keeping local-first behavior across version drift.

* fix(workspaces): preserve exact base refs in git actions

Resolve accepted display aliases back to the stored ref before comparisons and updates. Fail closed when a non-origin remote base has no explicit mutable merge target.

* fix(workspaces): reject conflicting qualified base refs

Display aliases remain accepted for compatibility, but a qualified ref carries remote identity and must not be canonicalized to a different stored upstream.

* test(server): make upstream fixtures portable

Keep the checkout-status fixture aligned with the optional upstream field, and select main explicitly when cloning a bare test remote whose default HEAD varies by platform.

* fix(workspaces): preserve exact upstream refs

Qualified remote refs now fail closed when pruned instead of switching lineage. Metadata accepts Git-valid upstream names rather than applying a narrower character whitelist.

* fix(workspaces): preserve qualified local base refs

Local tracking branches are exact upstream identities too. Keep heuristics only for legacy unqualified metadata so origin cannot replace a stored refs/heads base.

packages/app/e2e/browser/new-workspace.spec.ts

@@ -24,6 +24,10 @@ import {
   openProjectViaDaemon,
   openStartingRefPicker,
   pasteGithubPrUrl,
+  captureStartingRefPicker,
+  expectStartingRefRows,
+  startingRefRow,
+  submitNewWorkspaceEmpty,
   searchAndSelectBranchInPicker,
   selectBranchInPicker,
   selectGitHubPrInPicker,
@@ -31,7 +35,14 @@ import {
   selectWorkspaceIsolation,
   submitNewWorkspacePrompt,
 } from "../support/helpers/new-workspace";
-import { createTempGitRepo, readWorktreeBranchInfo } from "../support/helpers/workspace";
+import {
+  commitLocalOnly,
+  createTempGitRepo,
+  readRepoRef,
+  readWorktreeBaseMetadata,
+  readWorktreeBranchInfo,
+  trackForkUpstream,
+} from "../support/helpers/workspace";
 import {
   createLocalGithubPrFixture,
   cloneGithubRepoDefaultBranchOnly,
@@ -743,6 +754,142 @@ test.describe("New workspace flow", () => {
     }
   });
 
+  // The starting ref the daemon actually cuts from is the thing that broke: the picker said
+  // one ref and the worktree was created from another. Every assertion here reads the
+  // created worktree's commits or its recorded base, never the trigger text alone.
+  test.describe("default starting ref", () => {
+    async function openWorktreeComposerForRepo(
+      page: import("@playwright/test").Page,
+      repoPath: string,
+    ) {
+      const openedProject = await openProjectViaDaemon(client, repoPath);
+      localWorkspaceIds.add(openedProject.workspaceId);
+
+      await gotoAppShell(page);
+      await waitForSidebarHydration(page);
+      await openNewWorkspaceComposer(page, {
+        projectKey: openedProject.projectKey,
+        projectDisplayName: openedProject.projectDisplayName,
+      });
+      await selectWorkspaceIsolation(page, "worktree");
+      return openedProject;
+    }
+
+    async function createWorktreeAndRead(
+      page: import("@playwright/test").Page,
+      openedProject: Awaited<ReturnType<typeof openProjectViaDaemon>>,
+    ) {
+      await submitNewWorkspaceEmpty(page);
+      const createdWorkspace = await assertNewWorkspaceSidebarAndHeader(page, {
+        serverId: getServerId(),
+        client,
+        previousWorkspaceId: openedProject.workspaceId,
+        projectDisplayName: openedProject.projectDisplayName,
+      });
+      createdWorktreeDirectories.add(createdWorkspace.workspaceDirectory);
+      return {
+        ...createdWorkspace,
+        branchInfo: await readWorktreeBranchInfo({
+          worktreePath: createdWorkspace.workspaceDirectory,
+        }),
+      };
+    }
+
+    test("branches off the upstream when the local branch is ahead and the picker is untouched", async ({
+      page,
+    }) => {
+      const tempRepo = await createTempGitRepo("ref-default-ahead-", { withRemote: true });
+
+      try {
+        const originHead = readRepoRef(tempRepo.path, "refs/remotes/origin/main");
+        commitLocalOnly(tempRepo.path, "one");
+        const localHead = commitLocalOnly(tempRepo.path, "two");
+
+        const openedProject = await openWorktreeComposerForRepo(page, tempRepo.path);
+        const created = await createWorktreeAndRead(page, openedProject);
+
+        expect(created.branchInfo.hasAncestor(originHead)).toBe(true);
+        expect(created.branchInfo.hasAncestor(localHead)).toBe(false);
+      } finally {
+        await tempRepo.cleanup();
+      }
+    });
+
+    test("branches off the local ref when the local row is chosen explicitly", async ({
+      page,
+    }, testInfo) => {
+      const tempRepo = await createTempGitRepo("ref-default-local-pick-", { withRemote: true });
+
+      try {
+        commitLocalOnly(tempRepo.path, "one");
+        const localHead = commitLocalOnly(tempRepo.path, "two");
+
+        const openedProject = await openWorktreeComposerForRepo(page, tempRepo.path);
+
+        await openStartingRefPicker(page);
+        await expectStartingRefRows(page, [
+          "main, origin branch",
+          "main, local branch, 2 commits ahead of origin main",
+        ]);
+        const screenshotPath = testInfo.outputPath("ref-picker-local-ahead.png");
+        await captureStartingRefPicker(page, screenshotPath);
+        await testInfo.attach("Ref picker: local ahead of upstream", {
+          path: screenshotPath,
+          contentType: "image/png",
+        });
+        await startingRefRow(page, "main, local branch, 2 commits ahead of origin main").click();
+        await expectPickerSelected(page, "main (local)");
+
+        const created = await createWorktreeAndRead(page, openedProject);
+        expect(created.branchInfo.hasAncestor(localHead)).toBe(true);
+      } finally {
+        await tempRepo.cleanup();
+      }
+    });
+
+    test("branches off a fork's upstream remote and records the branch name", async ({
+      page,
+    }, testInfo) => {
+      const tempRepo = await createTempGitRepo("ref-default-fork-", { withRemote: true });
+
+      try {
+        const upstreamHead = await trackForkUpstream(tempRepo.path);
+        const originHead = readRepoRef(tempRepo.path, "refs/remotes/origin/main");
+
+        const openedProject = await openWorktreeComposerForRepo(page, tempRepo.path);
+
+        await openStartingRefPicker(page);
+        // Branch suggestions only know about origin, so the upstream the fork actually
+        // tracks gets its own row rather than silently sharing origin's. Two rows reading
+        // "main" is the ambiguity this whole change exists to remove.
+        await expectStartingRefRows(page, [
+          "main (upstream), upstream branch",
+          "main, origin branch",
+        ]);
+        await expectPickerSelected(page, "main (upstream)");
+        const screenshotPath = testInfo.outputPath("ref-picker-fork.png");
+        await captureStartingRefPicker(page, screenshotPath);
+        await testInfo.attach("Ref picker: fork tracking upstream/main", {
+          path: screenshotPath,
+          contentType: "image/png",
+        });
+        await closeBranchPicker(page);
+
+        const created = await createWorktreeAndRead(page, openedProject);
+
+        expect(created.branchInfo.hasAncestor(upstreamHead)).toBe(true);
+        expect(upstreamHead).not.toBe(originHead);
+        // The name is what the UI shows; the ref is what resolves back to this commit.
+        expect(await readWorktreeBaseMetadata(created.workspaceDirectory)).toEqual({
+          baseRefName: "main",
+          baseRef: "refs/remotes/upstream/main",
+        });
+      } finally {
+        await tempRepo.cleanup();
+      }
+    });
+  });
+
   test("branch picker opens via keyboard and selects the filtered option on Enter", async ({
     page,
   }) => {

packages/app/e2e/support/helpers/new-workspace.ts

@@ -348,6 +348,23 @@ export async function searchAndSelectBranchInPicker(page: Page, name: string): P
   await selectBranchInPicker(page, name);
 }
 
+// Ref picker rows are named for a user: "main, origin branch" is the upstream copy and
+// "main, local branch, 2 commits ahead of origin main" is the local one.
+export function startingRefRow(page: Page, accessibleName: string) {
+  return page.getByRole("button", { name: accessibleName, exact: true });
+}
+
+export async function expectStartingRefRows(page: Page, accessibleNames: string[]): Promise<void> {
+  for (const name of accessibleNames) {
+    await expect(startingRefRow(page, name)).toBeVisible({ timeout: 30_000 });
+  }
+}
+
+export async function captureStartingRefPicker(page: Page, screenshotPath: string): Promise<void> {
+  await expect(page.getByTestId("combobox-desktop-container")).toBeVisible({ timeout: 30_000 });
+  await page.getByTestId("combobox-desktop-container").screenshot({ path: screenshotPath });
+}
+
 export async function selectGitHubPrInPicker(page: Page, number: number): Promise<void> {
   const prRow = page.getByTestId(`new-workspace-ref-picker-pr-${number}`);
   await expect(prRow).toBeVisible({ timeout: 30_000 });

packages/app/e2e/support/helpers/workspace.ts

@@ -1,5 +1,5 @@
 import { execSync } from "node:child_process";
-import { mkdtemp, writeFile, rm, mkdir, realpath } from "node:fs/promises";
+import { mkdtemp, readFile, writeFile, rm, mkdir, realpath } from "node:fs/promises";
 import { tmpdir } from "node:os";
 import path from "node:path";
 
@@ -159,6 +159,80 @@ export async function createTempDirectory(prefix = "paseo-e2e-dir-"): Promise<Te
   };
 }
 
+/**
+ * A commit that exists only in the local checkout. The whole point of defaulting a new
+ * worktree to the upstream is that these commits do not leak into it.
+ */
+export function commitLocalOnly(repoPath: string, marker: string): string {
+  execSync(`git commit --allow-empty -m ${JSON.stringify(`local only ${marker}`)}`, {
+    cwd: repoPath,
+    stdio: "ignore",
+  });
+  return execSync("git rev-parse HEAD", { cwd: repoPath, stdio: "pipe" }).toString().trim();
+}
+
+/**
+ * A fork checkout: `origin` is the fork, `upstream` is the source repo, and the current
+ * branch tracks `upstream/main`. Upstream carries a commit origin does not, so a worktree
+ * based on the wrong remote is provable rather than coincidentally identical.
+ */
+export async function trackForkUpstream(repoPath: string): Promise<string> {
+  const upstreamDir = path.join(repoPath, "upstream.git");
+  const upstreamClone = await mkdtemp(path.join(await resolveTempRoot(), "paseo-e2e-upstream-"));
+  await mkdir(upstreamDir, { recursive: true });
+  execSync(`git init --bare -b main ${upstreamDir}`, { cwd: repoPath, stdio: "ignore" });
+  execSync(`git remote add upstream ${upstreamDir}`, { cwd: repoPath, stdio: "ignore" });
+  execSync("git push upstream main", { cwd: repoPath, stdio: "ignore" });
+
+  execSync(`git clone ${upstreamDir} ${upstreamClone}`, { stdio: "ignore" });
+  execSync('git config user.email "e2e@paseo.test"', { cwd: upstreamClone, stdio: "ignore" });
+  execSync('git config user.name "Paseo E2E"', { cwd: upstreamClone, stdio: "ignore" });
+  execSync("git config commit.gpgsign false", { cwd: upstreamClone, stdio: "ignore" });
+  execSync('git commit --allow-empty -m "upstream only"', {
+    cwd: upstreamClone,
+    stdio: "ignore",
+  });
+  execSync("git push origin main", { cwd: upstreamClone, stdio: "ignore" });
+  await rm(upstreamClone, { recursive: true, force: true });
+
+  execSync("git fetch upstream", { cwd: repoPath, stdio: "ignore" });
+  execSync("git branch --set-upstream-to=upstream/main main", {
+    cwd: repoPath,
+    stdio: "ignore",
+  });
+  return execSync("git rev-parse refs/remotes/upstream/main", { cwd: repoPath, stdio: "pipe" })
+    .toString()
+    .trim();
+}
+
+export function readRepoRef(repoPath: string, ref: string): string {
+  return execSync(`git rev-parse ${JSON.stringify(ref)}`, { cwd: repoPath, stdio: "pipe" })
+    .toString()
+    .trim();
+}
+
+/**
+ * The base identity the daemon recorded in worktree.json: the display name the UI reads back,
+ * and the exact ref every comparison and action resolves through.
+ */
+export async function readWorktreeBaseMetadata(
+  worktreePath: string,
+): Promise<{ baseRefName: string; baseRef?: string }> {
+  const gitDir = execSync("git rev-parse --absolute-git-dir", { cwd: worktreePath, stdio: "pipe" })
+    .toString()
+    .trim();
+  const metadata = JSON.parse(
+    await readFile(path.join(gitDir, "paseo", "worktree.json"), "utf8"),
+  ) as { baseRefName?: string; baseRef?: string };
+  if (!metadata.baseRefName) {
+    throw new Error(`worktree.json has no baseRefName: ${worktreePath}`);
+  }
+  return {
+    baseRefName: metadata.baseRefName,
+    ...(metadata.baseRef ? { baseRef: metadata.baseRef } : {}),
+  };
+}
+
 export async function readWorktreeBranchInfo({ worktreePath }: { worktreePath: string }): Promise<{
   currentBranch: string;
   hasAncestor: (ref: string) => boolean;

packages/app/src/screens/new-workspace-picker-item.test.ts

@@ -1,11 +1,12 @@
 import { describe, expect, it } from "vitest";
 import type { ForgeSearchItem } from "@getpaseo/protocol/messages";
-import type { CheckoutStatusPayload } from "@/git/checkout-status-cache";
 import {
+  type BranchPickerDetail,
   branchPickerOptionId,
   buildBranchPickerItems,
+  buildPickerOptionData,
+  defaultBasePickerItem,
   pickerItemToCheckoutRequest,
-  resolveCheckoutRequest,
   type PickerItem,
 } from "./new-workspace-picker-item";
 
@@ -104,7 +105,7 @@ describe("pickerItemToCheckoutRequest", () => {
 });
 
 describe("buildBranchPickerItems", () => {
-  it("hides the origin duplicate when local and origin match", () => {
+  it("keeps a single origin row when local and origin match", () => {
     expect(
       buildBranchPickerItems([
         {
@@ -120,14 +121,14 @@ describe("buildBranchPickerItems", () => {
       {
         kind: "branch",
         name: "main",
-        refName: "refs/heads/main",
-        accessibilityLabel: "main, local branch, up to date with origin main",
+        refName: "refs/remotes/origin/main",
+        accessibilityLabel: "main, origin branch",
         committerDate: 10,
       },
     ]);
   });
 
-  it("creates compact local and origin rows when the refs differ", () => {
+  it("puts the origin row first and disambiguates the local row when the refs differ", () => {
     expect(
       buildBranchPickerItems([
         {
@@ -143,17 +144,16 @@ describe("buildBranchPickerItems", () => {
       {
         kind: "branch",
         name: "main",
-        refName: "refs/heads/main",
-        divergenceLabel: "+3 −2",
-        accessibilityLabel: "main, local branch, 3 commits ahead and 2 behind origin main",
+        refName: "refs/remotes/origin/main",
+        accessibilityLabel: "main, origin branch",
         committerDate: 10,
       },
       {
         kind: "branch",
-        name: "origin/main",
-        refName: "refs/remotes/origin/main",
-        divergenceLabel: "+2 −3",
-        accessibilityLabel: "origin main, 2 commits ahead and 3 behind local main",
+        name: "main (local)",
+        refName: "refs/heads/main",
+        divergenceLabel: "+3 −2",
+        accessibilityLabel: "main, local branch, 3 commits ahead and 2 behind origin main",
         committerDate: 10,
       },
     ]);
@@ -172,9 +172,30 @@ describe("buildBranchPickerItems", () => {
     ).toEqual([
       {
         kind: "branch",
-        name: "origin/release",
+        name: "release",
         refName: "refs/remotes/origin/release",
-        accessibilityLabel: "origin release, origin branch",
+        accessibilityLabel: "release, origin branch",
+        committerDate: 5,
+      },
+    ]);
+  });
+
+  it("keeps the plain name for a local-only branch", () => {
+    expect(
+      buildBranchPickerItems([
+        {
+          name: "scratch",
+          committerDate: 5,
+          hasLocal: true,
+          hasRemote: false,
+        },
+      ]),
+    ).toEqual([
+      {
+        kind: "branch",
+        name: "scratch",
+        refName: "refs/heads/scratch",
+        accessibilityLabel: "scratch, local branch",
         committerDate: 5,
       },
     ]);
@@ -194,15 +215,15 @@ describe("buildBranchPickerItems", () => {
       {
         kind: "branch",
         name: "main",
-        refName: "refs/heads/main",
-        accessibilityLabel: "main, local branch",
+        refName: "refs/remotes/origin/main",
+        accessibilityLabel: "main, origin branch",
         committerDate: 10,
       },
       {
         kind: "branch",
-        name: "origin/main",
-        refName: "refs/remotes/origin/main",
-        accessibilityLabel: "origin main, origin branch",
+        name: "main (local)",
+        refName: "refs/heads/main",
+        accessibilityLabel: "main, local branch",
         committerDate: 10,
       },
     ]);
@@ -221,38 +242,101 @@ describe("buildBranchPickerItems", () => {
   });
 });
 
-describe("resolveCheckoutRequest", () => {
-  const checkoutStatus = {
-    currentBranch: "feature/current",
-  } as CheckoutStatusPayload;
+const mainRow: BranchPickerDetail = {
+  name: "main",
+  committerDate: 10,
+  hasLocal: true,
+  hasRemote: true,
+  localAhead: 2,
+  localBehind: 0,
+};
 
-  it("branches from the loaded current branch when nothing was picked", () => {
-    expect(resolveCheckoutRequest(null, checkoutStatus)).toEqual({
-      action: "branch-off",
-      refName: "feature/current",
+describe("buildPickerOptionData", () => {
+  it("marks origin and keeps an ahead local main explicit", () => {
+    const baseItem = defaultBasePickerItem({
+      currentBranch: "main",
+      upstreamRef: "refs/remotes/origin/main",
     });
+    const data = buildPickerOptionData({ branchDetails: [mainRow], prItems: [], baseItem });
+
+    expect(data.options.map((option) => option.label)).toEqual(["main", "main (local)"]);
+    expect(data.selectedOptionId).toBe(branchPickerOptionId("refs/remotes/origin/main"));
   });
 
-  it("prefers an explicit picker selection", () => {
-    expect(
-      resolveCheckoutRequest(
-        {
-          kind: "branch",
-          name: "feature/picked",
-          refName: "refs/heads/feature/picked",
-          accessibilityLabel: "feature/picked, local branch",
-        },
-        checkoutStatus,
-      ),
-    ).toEqual({
-      action: "branch-off",
-      refName: "refs/heads/feature/picked",
+  it("adds and disambiguates a fork upstream absent from branch suggestions", () => {
+    const baseItem = defaultBasePickerItem({
+      currentBranch: "main",
+      upstreamRef: "refs/remotes/upstream/main",
     });
+    const data = buildPickerOptionData({
+      branchDetails: [{ ...mainRow, localAhead: 0, localBehind: 0 }],
+      prItems: [],
+      baseItem,
+    });
+
+    expect(data.options.map((option) => option.label)).toEqual(["main (upstream)", "main"]);
+    expect(data.selectedOptionId).toBe(branchPickerOptionId("refs/remotes/upstream/main"));
   });
 
-  it("preserves the server-default intent for a detached checkout", () => {
+  it("marks a visible row on an old daemon when local and origin are in sync", () => {
+    const baseItem = defaultBasePickerItem({ currentBranch: "main" });
+    const data = buildPickerOptionData({
+      branchDetails: [{ ...mainRow, localAhead: 0, localBehind: 0 }],
+      prItems: [],
+      baseItem,
+    });
+
+    expect(data.options.map((option) => option.label)).toEqual(["main (local)", "main"]);
+    expect(data.selectedOptionId).toBe(branchPickerOptionId("refs/heads/main"));
+  });
+
+  it("keeps an explicit local selection marked", () => {
+    const baseItem: PickerItem = {
+      kind: "branch",
+      name: "main (local)",
+      refName: "refs/heads/main",
+      accessibilityLabel: "main, local branch",
+    };
+    const data = buildPickerOptionData({
+      branchDetails: [mainRow],
+      prItems: [],
+      baseItem,
+    });
+    const selected = data.itemById.get(data.selectedOptionId) ?? null;
+    expect(pickerItemToCheckoutRequest(selected)).toEqual({
+      action: "branch-off",
+      refName: "refs/heads/main",
+    });
+  });
+});
+
+describe("defaultBasePickerItem", () => {
+  it("uses origin when the current branch tracks origin", () => {
     expect(
-      resolveCheckoutRequest(null, { ...checkoutStatus, currentBranch: null }),
-    ).toBeUndefined();
+      defaultBasePickerItem({
+        currentBranch: "main",
+        upstreamRef: "refs/remotes/origin/main",
+      }),
+    ).toMatchObject({ refName: "refs/remotes/origin/main", name: "main" });
+  });
+
+  it("uses the exact non-origin upstream", () => {
+    expect(
+      defaultBasePickerItem({
+        currentBranch: "main",
+        upstreamRef: "refs/remotes/upstream/main",
+      }),
+    ).toMatchObject({ refName: "refs/remotes/upstream/main", name: "main" });
+  });
+
+  it("keeps old-daemon behavior local", () => {
+    expect(defaultBasePickerItem({ currentBranch: "main" })).toMatchObject({
+      refName: "refs/heads/main",
+      name: "main",
+    });
+  });
+
+  it("has no default for detached HEAD", () => {
+    expect(defaultBasePickerItem({ currentBranch: null })).toBeNull();
   });
 });

packages/app/src/screens/new-workspace-picker-item.ts

@@ -1,6 +1,7 @@
 import type { CreatePaseoWorktreeInput } from "@getpaseo/client/internal/daemon-client";
 import type { ForgeSearchItem } from "@getpaseo/protocol/messages";
-import type { CheckoutStatusPayload } from "@/git/checkout-status-cache";
+import type { ComboboxOptionModel } from "@/components/ui/combobox-options";
+import { getForgePresentation } from "@/git/forge";
 
 export interface BranchPickerDetail {
   name: string;
@@ -31,6 +32,8 @@ export type PickerCheckoutRequest = Pick<
 >;
 
 const BRANCH_OPTION_PREFIX = "branch:";
+const PR_OPTION_PREFIX = "github-pr:";
+const REMOTE_TRACKING_PREFIX = "refs/remotes/";
 
 export function branchPickerOptionId(refName: string): string {
   return `${BRANCH_OPTION_PREFIX}${refName}`;
@@ -82,11 +85,27 @@ export function buildBranchPickerItems(details: readonly BranchPickerDetail[]):
     const localBehind = detail.localBehind;
     const hasDivergence =
       hasLocal && hasRemote && localAhead !== undefined && localBehind !== undefined;
+    const refsDiffer = hasDivergence && (localAhead > 0 || localBehind > 0);
+    // One row when the two refs point at the same commit, two rows when they differ or
+    // when the divergence is unknown.
+    const showsBothRefs = hasLocal && hasRemote && (!hasDivergence || refsDiffer);
 
-    if (hasLocal) {
-      const localItem: Extract<PickerItem, { kind: "branch" }> = {
+    // The origin row goes first because it is the default base, and it never states
+    // divergence: it is the reference point the local row is measured against.
+    if (hasRemote) {
+      items.push({
         kind: "branch",
         name: detail.name,
+        refName: `refs/remotes/origin/${detail.name}`,
+        accessibilityLabel: `${detail.name}, origin branch`,
+        committerDate: detail.committerDate,
+      });
+    }
+
+    if (hasLocal && (showsBothRefs || !hasRemote)) {
+      const localItem: Extract<PickerItem, { kind: "branch" }> = {
+        kind: "branch",
+        name: showsBothRefs ? `${detail.name} (local)` : detail.name,
         refName: `refs/heads/${detail.name}`,
         accessibilityLabel: `${detail.name}, local branch`,
         committerDate: detail.committerDate,
@@ -101,33 +120,64 @@ export function buildBranchPickerItems(details: readonly BranchPickerDetail[]):
       }
       items.push(localItem);
     }
-
-    const refsDiffer = hasDivergence && (localAhead > 0 || localBehind > 0);
-    if (hasRemote && (!hasLocal || !hasDivergence || refsDiffer)) {
-      const remoteAhead = hasDivergence ? localBehind : 0;
-      const remoteBehind = hasDivergence ? localAhead : 0;
-      const remoteItem: Extract<PickerItem, { kind: "branch" }> = {
-        kind: "branch",
-        name: `origin/${detail.name}`,
-        refName: `refs/remotes/origin/${detail.name}`,
-        accessibilityLabel: `origin ${detail.name}, origin branch`,
-        committerDate: detail.committerDate,
-      };
-      if (hasDivergence) {
-        remoteItem.divergenceLabel = divergenceLabel(remoteAhead, remoteBehind);
-        remoteItem.accessibilityLabel = `origin ${detail.name}, ${divergenceAccessibility(
-          remoteAhead,
-          remoteBehind,
-          `local ${detail.name}`,
-        )}`;
-      }
-      items.push(remoteItem);
-    }
   }
 
   return items;
 }
 
+export interface BaseRefCheckoutStatus {
+  currentBranch: string | null;
+  upstreamRef?: string | null;
+}
+
+// Display only. The exact ref is what every request carries; this is just how a ref reads in
+// a row label, so "refs/remotes/origin/other-name" shows as "other-name".
+function branchNameFromRef(refName: string): string {
+  if (refName.startsWith("refs/heads/")) return refName.slice("refs/heads/".length);
+  if (refName.startsWith(REMOTE_TRACKING_PREFIX)) {
+    const remainder = refName.slice(REMOTE_TRACKING_PREFIX.length);
+    const separator = remainder.indexOf("/");
+    return separator === -1 ? remainder : remainder.slice(separator + 1);
+  }
+  return refName;
+}
+
+// Where a ref lives, for disambiguating two rows that would otherwise read the same.
+function refQualifier(refName: string): string | null {
+  if (refName.startsWith("refs/heads/")) return "local";
+  if (refName.startsWith(REMOTE_TRACKING_PREFIX)) {
+    const remainder = refName.slice(REMOTE_TRACKING_PREFIX.length);
+    const separator = remainder.indexOf("/");
+    return separator === -1 ? null : remainder.slice(0, separator);
+  }
+  return null;
+}
+
+// The one owner of "what do we branch off when the user picked nothing". The checkmarked
+// row, the trigger label, and the created ref all read this; computing it twice is how the
+// picker once showed local main while branching off something else.
+//
+// The upstream wins when the branch has one, because branching off the local ref silently
+// carries unpushed commits into the new workspace. The daemon sends the resolved ref rather
+// than a remote name, so a fork tracking upstream/main branches from upstream/main.
+export function defaultBasePickerItem(status: BaseRefCheckoutStatus): PickerItem | null {
+  const currentBranch = status.currentBranch;
+  if (!currentBranch) return null;
+  // COMPAT(checkoutUpstreamRef): added in v0.2.6, remove after 2027-02-01 once the daemon
+  // floor sends upstreamRef. Daemons that predate it omit the field, which lands on the
+  // local ref — the base those daemons always used.
+  const refName = status.upstreamRef ?? `refs/heads/${currentBranch}`;
+  // The upstream branch can be named differently from the local one, so the row reads the
+  // ref rather than the branch the user happens to be on.
+  const name = branchNameFromRef(refName);
+  return {
+    kind: "branch",
+    name,
+    refName,
+    accessibilityLabel: status.upstreamRef ? `${name}, upstream branch` : `${name}, local branch`,
+  };
+}
+
 export function pickerItemToCheckoutRequest(
   item: PickerItem | null,
 ): PickerCheckoutRequest | undefined {
@@ -159,15 +209,98 @@ export function pickerItemToCheckoutRequest(
   }
 }
 
-export function resolveCheckoutRequest(
-  selectedItem: PickerItem | null,
-  checkoutStatus: CheckoutStatusPayload,
-): PickerCheckoutRequest | undefined {
-  const selectedCheckoutRequest = pickerItemToCheckoutRequest(selectedItem);
-  if (selectedCheckoutRequest) return selectedCheckoutRequest;
-  if (!checkoutStatus.currentBranch) return undefined;
+export function prPickerOptionId(number: number): string {
+  return `${PR_OPTION_PREFIX}${number}`;
+}
+
+export function pickerOptionId(item: PickerItem): string {
+  return item.kind === "branch"
+    ? branchPickerOptionId(item.refName)
+    : prPickerOptionId(item.item.number);
+}
+
+function formatPrLabel(item: Pick<ForgeSearchItem, "forge" | "number" | "title">): string {
+  const presentation = getForgePresentation(item.forge ?? "github");
+  return `${presentation.numberPrefix}${item.number} ${item.title}`;
+}
+
+export function pickerItemLabel(item: PickerItem): string {
+  return item.kind === "branch" ? item.name : formatPrLabel(item.item);
+}
+
+export interface PickerOptionData {
+  options: ComboboxOptionModel[];
+  itemById: Map<string, PickerItem>;
+  selectedOptionId: string;
+}
+
+interface TimedOption {
+  option: ComboboxOptionModel;
+  timestamp: number;
+}
+
+export function buildPickerOptionData(input: {
+  branchDetails: readonly BranchPickerDetail[];
+  prItems: readonly ForgeSearchItem[];
+  baseItem: PickerItem | null;
+}): PickerOptionData {
+  const itemById = new Map<string, PickerItem>();
+  const timedOptions: TimedOption[] = [];
+
+  for (const branch of buildBranchPickerItems(input.branchDetails)) {
+    if (branch.kind !== "branch") continue;
+    const id = branchPickerOptionId(branch.refName);
+    itemById.set(id, branch);
+    timedOptions.push({
+      option: { id, label: pickerItemLabel(branch) },
+      timestamp: branch.committerDate ?? 0,
+    });
+  }
+
+  for (const pr of input.prItems) {
+    if (!pr.headRefName) continue;
+    const id = prPickerOptionId(pr.number);
+    itemById.set(id, { kind: "github-pr", item: pr });
+    const updatedAtMs = pr.updatedAt ? Date.parse(pr.updatedAt) : 0;
+    const timestamp = Number.isNaN(updatedAtMs) ? 0 : Math.floor(updatedAtMs / 1000);
+    timedOptions.push({ option: { id, label: formatPrLabel(pr) }, timestamp });
+  }
+
+  const baseItem = input.baseItem;
+  if (!baseItem) {
+    timedOptions.sort((a, b) => b.timestamp - a.timestamp);
+    return { options: timedOptions.map((t) => t.option), itemById, selectedOptionId: "" };
+  }
+
+  const selectedOptionId = pickerOptionId(baseItem);
+  if (!itemById.has(selectedOptionId)) {
+    // The label lives on the item, so the row and the trigger read it from the same place.
+    const labeledItem = disambiguate(baseItem, timedOptions);
+    itemById.set(selectedOptionId, labeledItem);
+    timedOptions.push({
+      option: { id: selectedOptionId, label: pickerItemLabel(labeledItem) },
+      // The base sorts first: it is what a workspace is created from unless you pick something.
+      timestamp: Number.POSITIVE_INFINITY,
+    });
+  }
+
+  timedOptions.sort((a, b) => b.timestamp - a.timestamp);
+  return { options: timedOptions.map((t) => t.option), itemById, selectedOptionId };
+}
+
+// Two rows reading "main" would be a coin flip for the user, so the added row says where its
+// ref lives. Only when it collides — a lone row needs no qualifier.
+function disambiguate(item: PickerItem, existing: readonly TimedOption[]): PickerItem {
+  if (item.kind !== "branch") return item;
+  if (!existing.some((entry) => entry.option.label === item.name)) return item;
+  const qualifier = refQualifier(item.refName);
+  if (!qualifier) return item;
+  const name = `${item.name} (${qualifier})`;
   return {
-    action: "branch-off",
-    refName: checkoutStatus.currentBranch,
+    ...item,
+    name,
+    // Accessibility labels are built as `${name}${suffix}`, so re-prefixing keeps the spoken
+    // label and the visible one the same string.
+    accessibilityLabel: `${name}${item.accessibilityLabel.slice(item.name.length)}`,
   };
 }

packages/app/src/screens/new-workspace-screen.tsx

@@ -61,7 +61,6 @@ import { useKeyboardActionHandler } from "@/hooks/use-keyboard-action-handler";
 import type { KeyboardActionId } from "@/keyboard/keyboard-action-dispatcher";
 import { useFormPreferences } from "@/hooks/use-form-preferences";
 import { useShortcutKeys } from "@/hooks/use-shortcut-keys";
-import { getForgePresentation } from "@/git/forge";
 import type { CreateAgentInitialValues } from "@/hooks/use-agent-form-state";
 import { generateMessageId } from "@/types/stream";
 import { toErrorMessage } from "@/utils/error-messages";
@@ -90,12 +89,14 @@ import {
   remapDraftCwdToWorkspace,
 } from "./new-workspace-fork-context";
 import {
-  branchPickerOptionId,
-  buildBranchPickerItems,
-  resolveCheckoutRequest,
+  buildPickerOptionData,
+  defaultBasePickerItem,
+  pickerItemLabel,
+  pickerItemToCheckoutRequest,
   type BranchPickerDetail,
   type PickerCheckoutRequest,
   type PickerItem,
+  type PickerOptionData,
 } from "./new-workspace-picker-item";
 import {
   clearPickerPrAttachmentForTargetChange,
@@ -169,12 +170,6 @@ interface NewWorkspaceScreenProps {
   draftId?: string;
 }
 
-interface PickerOptionData {
-  options: ComboboxOptionType[];
-  itemById: Map<string, PickerItem>;
-}
-
-const PR_OPTION_PREFIX = "github-pr:";
 const PROJECT_ICON_FALLBACK_FONT_SIZE = 10;
 // Stable reference so the keyboard-action handler doesn't re-register each render.
 const PROJECT_PICK_ACTIONS: readonly KeyboardActionId[] = ["workspace.project.pick"];
@@ -475,10 +470,6 @@ function ProjectOptionItem({
   );
 }
 
-function prOptionId(number: number): string {
-  return `${PR_OPTION_PREFIX}${number}`;
-}
-
 function NewWorkspacePickerOption({
   option,
   selected,
@@ -590,57 +581,10 @@ function AddProjectPickerAction({ onPress }: { onPress: () => void }) {
   );
 }
 
-function formatPrLabel(item: Pick<ForgeSearchItem, "forge" | "number" | "title">): string {
-  const presentation = getForgePresentation(item.forge ?? "github");
-  return `${presentation.numberPrefix}${item.number} ${item.title}`;
-}
-
-function pickerItemLabel(item: PickerItem): string {
-  return item.kind === "branch" ? item.name : formatPrLabel(item.item);
-}
-
-function pickerItemTriggerLabel(item: PickerItem): string {
-  return item.kind === "branch" ? item.name : formatPrLabel(item.item);
-}
-
 function newWorkspaceHostOptionTestID(serverId: string): string {
   return `new-workspace-host-picker-option-${serverId}`;
 }
 
-function computePickerOptionData(
-  branchDetails: readonly BranchPickerDetail[],
-  prItems: ReadonlyArray<ForgeSearchItem>,
-): PickerOptionData {
-  const idMap = new Map<string, PickerItem>();
-
-  interface TimedOption {
-    option: ComboboxOptionType;
-    timestamp: number;
-  }
-  const timedOptions: TimedOption[] = [];
-
-  for (const branch of buildBranchPickerItems(branchDetails)) {
-    if (branch.kind !== "branch") continue;
-    const id = branchPickerOptionId(branch.refName);
-    const option = { id, label: branch.name };
-    idMap.set(id, branch);
-    timedOptions.push({ option, timestamp: branch.committerDate ?? 0 });
-  }
-
-  for (const pr of prItems) {
-    if (!pr.headRefName) continue;
-    const id = prOptionId(pr.number);
-    const option = { id, label: formatPrLabel(pr) };
-    idMap.set(id, { kind: "github-pr", item: pr });
-    const updatedAtMs = pr.updatedAt ? Date.parse(pr.updatedAt) : 0;
-    const timestamp = Number.isNaN(updatedAtMs) ? 0 : Math.floor(updatedAtMs / 1000);
-    timedOptions.push({ option, timestamp });
-  }
-
-  timedOptions.sort((a, b) => b.timestamp - a.timestamp);
-  return { options: timedOptions.map((t) => t.option), itemById: idMap };
-}
-
 function IsolationPickerTrigger({
   pickerAnchorRef,
   onPress,
@@ -1655,7 +1599,6 @@ export function NewWorkspaceScreen({
     cwd: selectedSourceDirectory ?? "",
   });
 
-  const currentBranch = checkoutStatus?.currentBranch ?? null;
   const worktreeSupport = selectedProject
     ? getWorktreeSupportForHostProject({ project: selectedProject, serverId: selectedServerId })
     : "unsupported";
@@ -1709,25 +1652,23 @@ export function NewWorkspaceScreen({
     return githubPrSearchQuery.data?.items ?? [];
   }, [forgeSearchAuthenticated, githubPrSearchQuery.data?.items]);
 
-  const { options, itemById }: PickerOptionData = useMemo(
-    () => computePickerOptionData(branchDetails, prItems),
-    [branchDetails, prItems],
+  const baseItem = useMemo(
+    () => selectedItem ?? (checkoutStatus ? defaultBasePickerItem(checkoutStatus) : null),
+    [checkoutStatus, selectedItem],
+  );
+  const { options, itemById, selectedOptionId }: PickerOptionData = useMemo(
+    () =>
+      buildPickerOptionData({
+        branchDetails,
+        prItems,
+        baseItem,
+      }),
+    [baseItem, branchDetails, prItems],
   );
   const triggerLabel = useMemo(() => {
-    if (selectedItem) return pickerItemTriggerLabel(selectedItem);
-    return currentBranch ?? "main";
-  }, [currentBranch, selectedItem]);
-
-  const selectedOptionId = useMemo(() => {
-    if (!selectedItem) {
-      if (!currentBranch) return "";
-      const exactLocalId = branchPickerOptionId(`refs/heads/${currentBranch}`);
-      return itemById.has(exactLocalId) ? exactLocalId : branchPickerOptionId(currentBranch);
-    }
-    return selectedItem.kind === "branch"
-      ? branchPickerOptionId(selectedItem.refName)
-      : prOptionId(selectedItem.item.number);
-  }, [currentBranch, itemById, selectedItem]);
+    const displayItem = itemById.get(selectedOptionId);
+    return displayItem ? pickerItemLabel(displayItem) : "main";
+  }, [itemById, selectedOptionId]);
   const selectPickerItem = useCallback(
     (item: PickerItem) => {
       const nextAttachments = syncPickerPrAttachment({
@@ -1929,15 +1870,17 @@ export function NewWorkspaceScreen({
       }
       const connectedClient = withConnectedClient();
       const createsWorktree = !supportsWorkspaceMultiplicity || effectiveIsolation === "worktree";
-      const checkoutRequest = createsWorktree
-        ? resolveCheckoutRequest(
-            selectedItem,
-            await ensureCheckoutStatus({
-              queryClient,
-              client: connectedClient,
-              serverId: selectedServerId,
-              cwd: selectedSourceDirectory,
-            }),
+      const checkoutStatusForCreate = createsWorktree
+        ? await ensureCheckoutStatus({
+            queryClient,
+            client: connectedClient,
+            serverId: selectedServerId,
+            cwd: selectedSourceDirectory,
+          })
+        : null;
+      const checkoutRequest = checkoutStatusForCreate
+        ? pickerItemToCheckoutRequest(
+            selectedItem ?? defaultBasePickerItem(checkoutStatusForCreate),
           )
         : undefined;
       const normalizedWorkspace = supportsWorkspaceMultiplicity