fix interval

Author: topper-123

pandas/core/arrays/interval.py

@@ -46,7 +46,10 @@
 from pandas.errors import IntCastingNaNError
 from pandas.util._decorators import Appender
 
-from pandas.core.dtypes.cast import LossySetitemError
+from pandas.core.dtypes.cast import (
+    LossySetitemError,
+    maybe_upcast_numeric_to_64bit,
+)
 from pandas.core.dtypes.common import (
     is_categorical_dtype,
     is_dtype_equal,
@@ -304,7 +307,10 @@ def _ensure_simple_new_inputs(
         from pandas.core.indexes.base import ensure_index
 
         left = ensure_index(left, copy=copy)
+        left = maybe_upcast_numeric_to_64bit(left)
+
         right = ensure_index(right, copy=copy)
+        right = maybe_upcast_numeric_to_64bit(right)
 
         if closed is None and isinstance(dtype, IntervalDtype):
             closed = dtype.closed

pandas/tests/indexes/interval/test_interval.py

@@ -427,7 +427,9 @@ def test_maybe_convert_i8_numeric(self, make_key, any_real_numpy_dtype):
         key = make_key(breaks)
 
         result = index._maybe_convert_i8(key)
-        expected = Index(key)
+        kind = breaks.dtype.kind
+        expected_dtype = {"i": np.int64, "u": np.uint64, "f": np.float64}[kind]
+        expected = Index(key, dtype=expected_dtype)
         tm.assert_index_equal(result, expected)
 
     @pytest.mark.parametrize(