fix: Fix the loop bounds in BitmapBuilder::extend_each_repeated_from_slice_unchecked (#26928)

Author: dsprenkels

crates/polars-arrow/src/bitmap/builder.rs

@@ -242,13 +242,14 @@ impl BitmapBuilder {
         length: usize,
         repeats: usize,
     ) {
+        debug_assert!(8 * slice.len() >= offset + length);
         if repeats == 0 {
             return;
         }
         if repeats == 1 {
             return self.extend_from_slice_unchecked(slice, offset, length);
         }
-        for bit_idx in offset..length {
+        for bit_idx in offset..(offset + length) {
             let bit = (*slice.get_unchecked(bit_idx / 8) >> (bit_idx % 8)) & 1 != 0;
             self.extend_constant(repeats, bit);
         }

py-polars/tests/unit/operations/test_inequality_join.py

@@ -15,6 +15,8 @@
 if TYPE_CHECKING:
     from hypothesis.strategies import DrawFn, SearchStrategy
 
+    from tests.conftest import PlMonkeyPatch
+
 
 @pytest.mark.parametrize(
     ("pred_1", "pred_2"),
@@ -690,3 +692,4 @@ def test_boolean_predicate_join_where() -> None:
     assert "NESTED LOOP JOIN" in plan
 
     assert_frame_equal(q.collect(), expect)
+