Fill missing item-table pages from fully-visible inputs in context expansion

CHANGELOG.md

@@ -4,6 +4,7 @@
 ### Fixed
 
 - Context expansion no longer drops a retrieved result from a merged group when clipping to `search.max_context_chars`; groups whose clip would evict a constituent's evidence are returned as separate expanded results.
+- Context expansion now fills missing page metadata from input search results when the referenced items survive in the expanded result.
 
 ## [0.65.1] - 2026-07-10
 

haiku_rag_slim/haiku/rag/context.py

@@ -284,6 +284,20 @@ def _group_lost_constituent(built: SearchResult, group: list[SearchResult]) -> b
     )
 
 
+def _add_input_pages_for_surviving_refs(
+    pages: set[int], refs: list[str], original_results: list[SearchResult]
+) -> None:
+    """Fill missing item-table pages from inputs whose own refs all survived."""
+    surviving = set(refs)
+    if not surviving:
+        return
+    for result in original_results:
+        if not result.page_numbers or not result.doc_item_refs:
+            continue
+        if set(result.doc_item_refs) <= surviving:
+            pages.update(result.page_numbers)
+
+
 def _build_result(
     range_start: int,
     range_end: int,
@@ -374,6 +388,8 @@ def _build_result(
         else:
             pages, refs, labels = _collect_meta(base_spans)
 
+    _add_input_pages_for_surviving_refs(pages, refs, original_results)
+
     # Carry image_data and picture_captions from the originally retrieved
     # chunks, but only for constituents whose refs survive the window — a
     # chunk clipped out of the budget must not still ship its image to the

tests/test_context.py

@@ -1027,6 +1027,107 @@ class TestExpandWithItems:
             assert by_chunk["c2"].content == "B" * 400
             assert by_chunk["c2"].page_numbers == [2]
 
+    async def test_surviving_refs_fill_missing_item_pages_from_input(
+        self, temp_db_path
+    ):
+        """When a visible item has missing page metadata, use the input
+        result's page_numbers as a floor for that surviving ref."""
+        from haiku.rag.client import HaikuRAG
+
+        async with HaikuRAG(temp_db_path, create=True) as rag:
+            items = [
+                DocumentItem(
+                    document_id="doc-1",
+                    position=0,
+                    self_ref="#/texts/0",
+                    label="text",
+                    text="Visible item with missing item-table pages.",
+                    page_numbers=[],
+                ),
+                DocumentItem(
+                    document_id="doc-1",
+                    position=1,
+                    self_ref="#/texts/1",
+                    label="text",
+                    text="Visible item with stored item-table pages.",
+                    page_numbers=[8],
+                ),
+            ]
+            await rag.document_item_repository.create_items("doc-1", items)
+
+            r_missing_item_page = SearchResult(
+                content=items[0].text,
+                score=0.9,
+                chunk_id="c-missing",
+                document_id="doc-1",
+                doc_item_refs=["#/texts/0"],
+                page_numbers=[7],
+            )
+            r_with_item_page = SearchResult(
+                content=items[1].text,
+                score=0.8,
+                chunk_id="c-present",
+                document_id="doc-1",
+                doc_item_refs=["#/texts/1"],
+                page_numbers=[8],
+            )
+            expanded = await expand_with_items(
+                rag.document_item_repository,
+                "doc-1",
+                [r_missing_item_page, r_with_item_page],
+                5000,
+            )
+
+            assert len(expanded) == 1
+            assert set(expanded[0].doc_item_refs) == {"#/texts/0", "#/texts/1"}
+            assert expanded[0].page_numbers == [7, 8]
+
+    async def test_input_pages_not_added_for_clipped_out_refs(self, temp_db_path):
+        """Input page metadata is not blindly unioned when only some of a
+        constituent's refs survive the clip window."""
+        from haiku.rag.client import HaikuRAG
+
+        item0_text = "LEFTMARK " + "a" * 91
+        item1_text = "RIGHTMARK " + "b" * 70
+        async with HaikuRAG(temp_db_path, create=True) as rag:
+            items = [
+                DocumentItem(
+                    document_id="doc-1",
+                    position=0,
+                    self_ref="#/texts/0",
+                    label="text",
+                    text=item0_text,
+                    page_numbers=[1],
+                ),
+                DocumentItem(
+                    document_id="doc-1",
+                    position=1,
+                    self_ref="#/texts/1",
+                    label="text",
+                    text=item1_text,
+                    page_numbers=[2],
+                ),
+            ]
+            await rag.document_item_repository.create_items("doc-1", items)
+
+            result = SearchResult(
+                content=item0_text,
+                score=0.9,
+                chunk_id="c-both",
+                document_id="doc-1",
+                doc_item_refs=["#/texts/0", "#/texts/1"],
+                page_numbers=[1, 2],
+            )
+            expanded = await expand_with_items(
+                rag.document_item_repository, "doc-1", [result], 100
+            )
+
+            assert len(expanded) == 1
+            assert "LEFTMARK" in expanded[0].content
+            assert "RIGHTMARK" not in expanded[0].content
+            assert expanded[0].doc_item_refs == ["#/texts/0"]
+            assert expanded[0].page_numbers == [1]
+
     async def test_fuzzy_match_preserves_central_marker(self, temp_db_path):
         """The chunk's text need not be verbatim in the joined item text: a clean
         central marker is still located via the central-slice anchor."""