fix(pending post page): prevent crash and ensure redirect to "not found" on invalid URL

src/components/board-header/board-header.tsx

@@ -63,7 +63,7 @@ const BoardHeader = () => {
             ? shortAddress.endsWith('.eth') || shortAddress.endsWith('.sol')
               ? shortAddress.slice(0, -4)
               : shortAddress
-            : Plebbit.getShortAddress(subplebbitAddress))}
+            : subplebbitAddress && Plebbit.getShortAddress(subplebbitAddress))}
         {(isOffline || isOnlineStatusLoading) && !isInAllView && !isInSubscriptionsView && !isInModView && (
           <span className={styles.offlineIconWrapper}>
             <Tooltip content={offlineTitle}>

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

@@ -14,13 +14,10 @@ const PendingPost = () => {
 
   const isValidAccountCommentIndex =
     !accountCommentIndex ||
-    // Check if it's a valid positive integer
     (!isNaN(parseInt(accountCommentIndex)) &&
       parseInt(accountCommentIndex) >= 0 &&
       Number.isInteger(parseFloat(accountCommentIndex)) &&
-      // Allow index to be at most 1 position beyond the current length
-      // This handles the case where a new post is being created
-      (accountComments?.length === 0 || parseInt(accountCommentIndex) <= accountComments.length));
+      (accountComments?.length === 0 || parseInt(accountCommentIndex) < accountComments.length));
 
   useEffect(() => {
     if (!isValidAccountCommentIndex) {