fix(application): check a next version's draft for guest-pod links

docs/guest-mode.md

@@ -80,7 +80,9 @@ brings one in, for a guest and a logged-in user alike:
   address in it, such as a card's picture or what it's about
   (`releaseLinksGuestPod`);
 - so is a release made a [draft](studio.md#drafts), from a file or as
-  a next version;
+  a next version. So is a next version whose series or publisher, as
+  the documents they're described in say, links to it, such as by the
+  earlier versions the series lists (`dcat:hasVersion`);
 - so is a [deck file](studio.md#import-and-export) with such an
   address (`deckFileLinksGuestPod`). The deck's, its cards' and their
   documents' own addresses may name it: the import gives them new

docs/studio.md

@@ -1606,7 +1606,12 @@ anywhere else is shown by no editor and checked by no rule, but would
 be published with the draft, so such a release is refused too
 (`releaseForeignPart`). So is one that links to the guest's pod by an
 IRI (`releaseLinksGuestPod`): a guest's draft of it couldn't be kept
-([guest-mode.md](guest-mode.md#what-comes-from-outside)). Its text may
+([guest-mode.md](guest-mode.md#what-comes-from-outside)). For a next
+version, the draft as it's made is held to this too. It takes what the
+documents its series and publisher are described in say, such as the
+earlier versions the series lists (`dcat:hasVersion`). It's refused,
+with nothing written, when it links to the guest's pod by an IRI other
+than its own URL or its own subjects' (`<draft>#id`). Its text may
 name any address.
 
 Of a release's other statements, the draft keeps those of the release,

packages/application/src/releaseDrafts.test.ts

@@ -4,7 +4,7 @@
 
 import { describe, expect, it, vi } from "vitest";
 import { AppError } from "@solid-memo/domain/appError";
-import { GUEST_INSTANCE_URL } from "@solid-memo/domain/guest";
+import { GUEST_INSTANCE_URL, GUEST_ORIGIN, GUEST_WEBID } from "@solid-memo/domain/guest";
 import type { Card, Deck } from "@solid-memo/domain/deck";
 import {
   draftSummaryOf,
@@ -460,6 +460,57 @@ describe("createReleaseDraft", () => {
     expect(repository.create).toHaveBeenCalledOnce();
   });
 
+  it("refuses a next version whose release's linked documents link to the guest's pod, writing nothing (GHSA-vrq3-87m3-6rgg)", async () => {
+    const { useCases, repository, created } = setUp();
+    const OUTSIDE = "https://elsewhere.example/decks/solid/v1.ttl";
+    const SERIES = "https://elsewhere.example/decks/index.ttl#solid";
+    const outside = rebaseDraft(courseDraft(), OUTSIDE);
+    // The release itself names nothing at the guest's pod: its series is described in another document.
+    const release = {
+      ...outside,
+      root: { ...outside.root, inSeries: SERIES, isVersionOf: SERIES },
+      triples: outside.triples.filter((triple) => !triple.subject.endsWith("#series")),
+    };
+    const iri = (value: string) => ({ kind: "iri" as const, value });
+    const series: DraftTriple = {
+      subject: SERIES,
+      predicate: RDF_TYPE,
+      object: iri("http://www.w3.org/ns/dcat#DatasetSeries"),
+    };
+    const linking: DraftTriple[] = [
+      series,
+      {
+        subject: SERIES,
+        predicate: "http://www.w3.org/ns/dcat#theme",
+        object: iri(`${GUEST_ORIGIN}x`),
+      },
+      {
+        subject: SERIES,
+        predicate: "http://purl.org/dc/terms/publisher",
+        object: iri("HTTPS://GUEST.solid-memo.invalid:443/me"),
+      },
+    ];
+    const refused = new AppError("releaseLinksGuestPod", { url: OUTSIDE });
+    for (const instance of [GUEST_INSTANCE_URL, INSTANCE]) {
+      repository.readRelease.mockResolvedValueOnce(release);
+      repository.readLinked.mockResolvedValueOnce(linking);
+      await expect(
+        useCases.createReleaseDraft(instance, { kind: "nextVersionOf", url: OUTSIDE }, GUEST_WEBID),
+      ).rejects.toEqual(refused);
+    }
+    expect(repository.create).not.toHaveBeenCalled();
+    // A guest's next version names its own place at the guest's pod, which a copy of it moves.
+    repository.readRelease.mockResolvedValueOnce(release);
+    repository.readLinked.mockResolvedValueOnce([series]);
+    await useCases.createReleaseDraft(
+      GUEST_INSTANCE_URL,
+      { kind: "nextVersionOf", url: OUTSIDE },
+      GUEST_WEBID,
+    );
+    expect(created().url).toBe(draftUrlOf(GUEST_INSTANCE_URL, "solid", 2));
+    expect(created().triples).toContainEqual(series);
+  });
+
   it("refuses a release with a card outside it, writing nothing, but not one of its own its records do not hold", async () => {
     const { useCases, repository } = setUp();
     const typed = (subject: string, type: string): DraftTriple => ({

packages/application/src/releaseDrafts.ts

@@ -6,7 +6,7 @@ import { AppError } from "@solid-memo/domain/appError";
 import type { Deck } from "@solid-memo/domain/deck";
 import type { KeptDocuments } from "@solid-memo/domain/instance";
 import { catalogUrlOf, isDocumentIn } from "@solid-memo/domain/instanceLayout";
-import { draftAddressesGuest, isGuestUrl } from "@solid-memo/domain/guest";
+import { draftAddressesGuest, isGuestPodIri, isGuestUrl } from "@solid-memo/domain/guest";
 import { DECK_FILE_ACCEPT, deckFileFormatOf } from "@solid-memo/domain/deckFile";
 import { shown, tidiedStated, type LangText } from "@solid-memo/domain/langText";
 import { deckToDraft } from "@solid-memo/domain/release/deckToDraft";
@@ -269,6 +269,23 @@ function draftable(read: ReleaseDraft): ReleaseDraft {
   return ownStatements(release);
 }
 
+/**
+ * Whether a draft links to the guest's pod by an IRI other than its own
+ * or one of its subjects' (`<draft>#id`), the only ones a copy of it
+ * moves (copyReleaseDraft): a guest's draft that does could not be kept
+ * (GHSA-hc3p-fpwj-fvjp). A next version takes statements from the
+ * documents its release links to, which the release's own check
+ * (draftable) does not see (GHSA-vrq3-87m3-6rgg).
+ */
+function linksGuestPodBeyond(draft: ReleaseDraft): boolean {
+  let links = false;
+  rebaseDraft(draft, draft.url, (iri) => {
+    links ||= isGuestPodIri(iri) && iri !== draft.url && !iri.startsWith(`${draft.url}#`);
+    return iri;
+  });
+  return links;
+}
+
 /**
  * Whether a statement types the release an agent or distribution, or
  * names it: it can have no record of those, so the Studio would show no
@@ -632,12 +649,17 @@ export function createReleaseDraftUseCases({
             draft: await create(
               instanceUrl,
               { title: release.root.title ?? {}, ...(name === undefined ? {} : { name }), version },
-              (url) =>
-                nextVersionDraft(
+              (url) => {
+                const draft = nextVersionDraft(
                   inItsPlace(release, url),
                   url,
                   untaken(linked, takenBy(release, url)),
-                ),
+                );
+                // What the linked documents state is checked as the draft has it, as the release was (draftable).
+                if (linksGuestPodBeyond(draft))
+                  throw new AppError("releaseLinksGuestPod", { url: release.url });
+                return draft;
+              },
             ),
           };
         }