fix(pending-post): preserve sparse retry routes

src/views/pending-post/__tests__/pending-post.test.tsx

@@ -10,6 +10,7 @@ const act = (React as { act?: (cb: () => void | Promise<void>) => void | Promise
 type TestComment = {
   cid?: string;
   communityAddress?: string;
+  index?: number;
 };
 
 const testState = vi.hoisted(() => ({
@@ -136,6 +137,29 @@ describe('PendingPost', () => {
     expect(testState.navigateMock).toHaveBeenCalledWith('/not-found', { replace: true });
   });
 
+  it('keeps sparse pending account comment indices addressable', async () => {
+    testState.accountCommentIndex = '1';
+    testState.accountComments = [{ index: 1 }];
+    testState.post = {
+      communityAddress: 'music-posting.eth',
+      index: 1,
+    };
+
+    await renderPendingPost();
+
+    expect(container.querySelector('[data-testid="post-view"]')?.textContent).toBe('no-post');
+    expect(testState.navigateMock).not.toHaveBeenCalledWith('/not-found', { replace: true });
+  });
+
+  it('redirects missing sparse pending account comment indices to not found', async () => {
+    testState.accountCommentIndex = '0';
+    testState.accountComments = [{ index: 1 }];
+
+    await renderPendingPost();
+
+    expect(testState.navigateMock).toHaveBeenCalledWith('/not-found', { replace: true });
+  });
+
   it('redirects resolved pending posts to the canonical thread route', async () => {
     testState.accountCommentIndex = '1';
     testState.accountComments = [{}, {}];

src/views/pending-post/pending-post.tsx

@@ -7,6 +7,30 @@ import { getCommentCommunityAddress } from '../../lib/utils/comment-utils';
 import { getBoardPath } from '../../lib/utils/route-utils';
 import { Post } from '../post';
 
+type PendingAccountComment = {
+  index?: number;
+};
+
+const hasPendingAccountCommentIndex = (accountComments: PendingAccountComment[] | undefined, accountCommentIndex: number) => {
+  if (!accountComments || accountComments.length === 0) {
+    return true;
+  }
+
+  let hasExplicitIndices = false;
+  for (const accountComment of accountComments) {
+    if (typeof accountComment?.index !== 'number') {
+      continue;
+    }
+
+    hasExplicitIndices = true;
+    if (accountComment.index === accountCommentIndex) {
+      return true;
+    }
+  }
+
+  return hasExplicitIndices ? false : accountCommentIndex < accountComments.length;
+};
+
 const PendingPost = () => {
   const { accountComments } = useAccountComments();
   const { accountCommentIndex } = useParams<{ accountCommentIndex?: string }>();
@@ -23,7 +47,7 @@ const PendingPost = () => {
     (hasNormalizedAccountCommentIndex &&
       normalizedAccountCommentIndex >= 0 &&
       Number.isInteger(normalizedAccountCommentIndex) &&
-      (accountComments?.length === 0 || normalizedAccountCommentIndex < accountComments.length));
+      hasPendingAccountCommentIndex(accountComments, normalizedAccountCommentIndex));
 
   useEffect(() => {
     if (!isValidAccountCommentIndex) {