fix: lit/library-list search by title, own entries for authors, cursor without hidden rows (L3)

search uses search_columns post_title; users without edit_others_posts on
et_pb_layout query their own entries only (PostGuard::ownPostsOnly); the
cursor counts the entries shown, never the rows left out.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

src/Integrations/Divi/Library/DiviLibraryStore.php

@@ -70,8 +70,9 @@ class DiviLibraryStore
     /**
      * Published entries, $limit + 1 of them (Cursor::page() tells whether there are more).
      *
-     * @param array{layout_type?: string, scope?: string, search?: string, category?: string} $filters
-     *        scope: "global" or "normal"; category: name of a layout_category term.
+     * @param array{layout_type?: string, scope?: string, search?: string, category?: string, author?: int} $filters
+     *        scope: "global" or "normal"; search: in the title; category: name of a layout_category
+     *        term; author: only this user's entries.
      * @return list<WP_Post>
      */
     public function find(array $filters, int $limit, int $offset): array
@@ -101,6 +102,12 @@ class DiviLibraryStore
         ];
         if (($filters['search'] ?? '') !== '') {
             $args['s'] = $filters['search'];
+            // Audit L3: the title only – content is block JSON, and entries the user may not read
+            // must not be findable by their content.
+            $args['search_columns'] = ['post_title'];
+        }
+        if (is_int($filters['author'] ?? null)) {
+            $args['author'] = $filters['author'];
         }
         if ($taxQuery !== []) {
             // phpcs:ignore WordPress.DB.SlowDBQuery.slow_db_query_tax_query -- the library is small.

src/Integrations/Divi/Library/LibraryListAbility.php

@@ -29,7 +29,7 @@ defined('ABSPATH') || exit;
  */
 final class LibraryListAbility implements Ability
 {
-    /** At most this many entries are looked at per call while skipping entries the user may not edit. */
+    /** Rows looked at per call beyond the entries already shown (the cursor), skipping hidden ones. */
     public const MAX_SCAN = 500;
 
     public function __construct(
@@ -158,42 +158,48 @@ final class LibraryListAbility implements Ability
             ],
             static fn (mixed $value): bool => is_string($value) && $value !== ''
         );
+        // Audit L3: without edit_others_posts the query holds the own entries only (PostGuard).
+        $author = PostGuard::ownPostsOnly(DiviLibraryStore::POST_TYPE);
+        if ($author !== null) {
+            $filters['author'] = $author;
+        }
 
         return $this->page($filters, Cursor::limit($input['limit'] ?? null), $offset);
     }
 
     /**
-     * One page of the entries the user may edit. The cursor counts the store's rows, so entries
-     * left out never shift a page; next_cursor points at the next readable entry, null when none
-     * follows (or the scan cap is reached with nothing left).
+     * One page of the entries the user may edit. The cursor counts the entries this user was shown
+     * ($skip), never the rows left out (audit L3), so it tells nothing about hidden entries; each call
+     * reads the rows from the start again and skips the first $skip readable ones. next_cursor is
+     * null when no readable entry follows (or the scan cap is reached with nothing found).
      *
-     * @param array<string, string> $filters
+     * @param array<string, string|int> $filters
      * @return array{items: list<array<string, mixed>>, next_cursor: ?string}
      */
-    private function page(array $filters, int $limit, int $offset): array
+    private function page(array $filters, int $limit, int $skip): array
     {
         $store = $this->access->store();
         $items = [];
-        $position = $offset;
-        while ($position - $offset < self::MAX_SCAN) {
+        $readable = 0;
+        $position = 0;
+        while ($position < $skip + self::MAX_SCAN) {
             $rows = $store->find($filters, $limit, $position);
             foreach ($rows as $post) {
-                if ($this->access->canRead($post) !== null) {
-                    ++$position;
+                ++$position;
+                if ($this->access->canRead($post) !== null || $readable++ < $skip) {
                     continue;
                 }
                 if (count($items) === $limit) {
-                    return ['items' => $items, 'next_cursor' => Cursor::encode($position)];
+                    return ['items' => $items, 'next_cursor' => Cursor::encode($skip + $limit)];
                 }
                 $items[] = $store->describe($post);
-                ++$position;
             }
             if (count($rows) <= $limit) {
                 return ['items' => $items, 'next_cursor' => null];
             }
         }
 
-        return ['items' => $items, 'next_cursor' => Cursor::encode($position)];
+        return ['items' => $items, 'next_cursor' => $items === [] ? null : Cursor::encode($skip + count($items))];
     }
 
     /**