fix(edit): handle empty cached search snapshots

Author: nijel

docs/changes.rst

@@ -39,6 +39,7 @@ Weblate 2026.7
 * Project and workspace translation license defaults now follow component and project licenses more closely.
 * Component and category API ``PATCH`` requests no longer remove the category when the field is omitted.
 * Hardened HTML and AJAX object lookups against private project enumeration.
+* Out-of-range cached search offsets no longer cause translate form submissions to fail.
 * Document and translation-memory uploads now enforce :setting:`TRANSLATION_UPLOAD_MAX_SIZE`, and API document uploads validate file extensions.
 * :ref:`check-rst-syntax` now detects inline roles wrapped in stray backticks.
 * :ref:`auto-translation` no longer validates hidden component fields when using machine translation.

weblate/trans/tests/test_edit.py

@@ -102,6 +102,7 @@ def test_search_session_snapshot_handles_full_and_partial_windows(self) -> None:
                 {"partial_ids": [10, 11], "partial_offset": 3}, 2, 1
             )
         )
+        self.assertIsNone(get_search_session_snapshot({"ids": [1, 2, 3]}, 5, 1))
 
     def test_search_session_snapshot_rejects_malformed_ids(self) -> None:
         self.assertIsNone(get_search_session_snapshot({"ids": ["invalid"]}, 1, 1))

weblate/trans/views/edit.py

@@ -457,6 +457,8 @@ def get_search_session_snapshot(
             offset = max(len(unit_ids) - page_size + 1, 1)
         page_offset = offset - 1
         page_ids = unit_ids[page_offset : page_offset + page_size + 1]
+        if not page_ids:
+            return None
         return SearchSnapshot(
             ids=page_ids,
             offset=offset,