RDBC-1026: skip() without take() no longer forces 0 results

__build_pagination emitted _page_size or 0 = 0 when page_size was None,
generating "limit n, 0" in RQL which told the server to return 0 items.

Fix: pass None (null) as page_size when take() was not called, matching
the C# reference which passes a null long? parameter. The server treats
a null limit as no limit.

Regression test: test_query_pagination.py verifies that skip(n) without
a preceding take() call returns documents starting from offset n.

Author: redknightlois

ravendb/documents/session/query.py

@@ -923,7 +923,7 @@ def __build_pagination(self, query_text: List[str]) -> None:
             query_text.append(" limit $")
             query_text.append(self.__add_query_parameter(self._start or 0))
             query_text.append(", $")
-            query_text.append(self.__add_query_parameter(self._page_size or 0))
+            query_text.append(self.__add_query_parameter(self._page_size))
 
     def __build_include(self, query_text: List[str]) -> None:
         if (

ravendb/tests/session_tests/test_query_pagination.py

@@ -0,0 +1,72 @@
+"""
+Query pagination: skip() without take() returns the expected documents.
+
+C# reference: FastTests/Issues/RavenDB_20542.cs
+  AddLongSkipToLINQ
+"""
+
+from ravendb.tests.test_base import TestBase
+
+
+class UserSkip:
+    def __init__(self, name: str = ""):
+        self.name = name
+
+
+class TestRavenDB20542(TestBase):
+    def setUp(self):
+        super().setUp()
+        with self.store.open_session() as session:
+            for name in ["AA", "BB", "CC"]:
+                session.store(UserSkip(name=name))
+            session.save_changes()
+
+    def test_skip_one_without_take_returns_remaining_documents(self):
+        """
+        C# spec: session.Query<User>().Skip(1).ToList() → 2 results (AA, BB, CC minus 1).
+        """
+        with self.store.open_session() as session:
+            q = session.advanced.document_query(object_type=UserSkip)
+            q = q.skip(1)
+            results = list(q)
+
+        self.assertEqual(
+            2,
+            len(results),
+            f"skip(1) on 3 documents should return 2, but got {len(results)}",
+        )
+
+    def test_skip_with_max_long_returns_no_results(self):
+        """
+        C# spec: session.Query<User>().Skip(long.MaxValue).ToList() → 0 results.
+        Skipping past all documents returns an empty list.
+        """
+        with self.store.open_session() as session:
+            q = session.advanced.document_query(object_type=UserSkip)
+            q = q.skip(9223372036854775807)
+            results = list(q)
+
+        self.assertEqual(
+            0,
+            len(results),
+            f"skip(long.MaxValue) should skip all documents and return 0, got {len(results)}",
+        )
+
+    # ------------------------------------------------------------------ #
+    #  Baseline: skip() combined with take()                              #
+    # ------------------------------------------------------------------ #
+
+    def test_skip_with_take_returns_correct_slice(self):
+        """
+        Baseline: skip(1).take(10) on 3 documents returns 2.
+        """
+        with self.store.open_session() as session:
+            q = session.advanced.document_query(object_type=UserSkip)
+            q = q.skip(1).take(10)
+            results = list(q)
+
+        self.assertEqual(
+            2,
+            len(results),
+            f"skip(1).take(10) on 3 documents should return 2, got {len(results)}",
+        )