catch dest_offset < 0

python/src/nanoarrow/_lib.pyx

@@ -1834,11 +1834,12 @@ cdef class CBufferView:
             PyBuffer_Release(&buffer)
             raise ValueError("Destination buffer has itemsize != 1")
 
-        if buffer.len < (dest_offset + length):
+        if dest_offset < 0 or buffer.len < (dest_offset + length):
             buffer_len = buffer.len
             PyBuffer_Release(&buffer)
             raise IndexError(
-                f"Can't unpack {length} elements into buffer of size {buffer_len}"
+                f"Can't unpack {length} elements into buffer of size {buffer_len} "
+                f"with dest_offset = {dest_offset}"
             )
 
         ArrowBitsUnpackInt8(

python/tests/test_c_buffer_view.py

@@ -83,6 +83,10 @@ def test_buffer_view_bool_unpack():
     view.unpack_bits_into(out, dest_offset=2)
     assert list(out) == [255, 255, 1, 0, 0, 1, 0, 0, 0, 0]
 
+    # Check error requesting out-of-bounds dest_offset
+    with pytest.raises(IndexError, match="Can't unpack"):
+        view.unpack_bits_into(out, dest_offset=-1)
+
     # Check errors from requesting out-of-bounds slices
     msg = "do not describe a valid slice"
     with pytest.raises(IndexError, match=msg):