Speed up checkpoints v2 pre-push recovery

cmd/entire/cli/checkpoint/remote/git.go

@@ -309,6 +309,22 @@ func ResolveFetchTarget(ctx context.Context, target string) (string, error) {
 	return url, nil
 }
 
+// ResolveFilteredFetchTarget returns a fetch target suitable for an explicit
+// filtered fetch. Remote names are resolved to URLs even when the repo-level
+// filtered_fetches setting is disabled, because callers that pass
+// --filter=blob:none must not let git persist promisor settings onto a named
+// remote like origin.
+func ResolveFilteredFetchTarget(ctx context.Context, target string) (string, error) {
+	if target == "" || IsURL(target) || isLocalPath(target) {
+		return target, nil
+	}
+	url, err := GetRemoteURL(ctx, target)
+	if err != nil {
+		return "", fmt.Errorf("get remote URL: %w", err)
+	}
+	return url, nil
+}
+
 // newCommand creates an exec.Cmd for a git operation that may need
 // checkpoint token authentication. If ENTIRE_CHECKPOINT_TOKEN is set:
 //   - if the target in args is (or resolves to) an SSH remote, the target is

cmd/entire/cli/checkpoint/remote/git_test.go

@@ -256,6 +256,36 @@ func TestResolveFetchTarget(t *testing.T) {
 	})
 }
 
+// Not parallel: uses t.Chdir()
+func TestResolveFilteredFetchTarget_AlwaysResolvesRemoteName(t *testing.T) {
+	ctx := context.Background()
+
+	tmpDir := t.TempDir()
+	testutil.InitRepo(t, tmpDir)
+	testutil.WriteFile(t, tmpDir, "f.txt", "init")
+	testutil.GitAdd(t, tmpDir, "f.txt")
+	testutil.GitCommit(t, tmpDir, "init")
+
+	cmd := exec.CommandContext(ctx, "git", "remote", "add", "origin", "https://github.com/org/repo.git")
+	cmd.Dir = tmpDir
+	cmd.Env = testutil.GitIsolatedEnv()
+	require.NoError(t, cmd.Run())
+
+	t.Chdir(tmpDir)
+
+	target, err := ResolveFilteredFetchTarget(ctx, "origin")
+	require.NoError(t, err)
+	assert.Equal(t, "https://github.com/org/repo.git", target)
+
+	target, err = ResolveFilteredFetchTarget(ctx, "https://github.com/org/repo.git")
+	require.NoError(t, err)
+	assert.Equal(t, "https://github.com/org/repo.git", target)
+
+	target, err = ResolveFilteredFetchTarget(ctx, "../repo.git")
+	require.NoError(t, err)
+	assert.Equal(t, "../repo.git", target)
+}
+
 func TestAppendCheckpointTokenEnv(t *testing.T) {
 	t.Parallel()