fix bug

Author: lfffkh

pandas/core/construction.py

@@ -32,6 +32,7 @@
     maybe_cast_to_integer_array,
     maybe_convert_platform,
     maybe_infer_to_datetimelike,
+    maybe_promote,
 )
 from pandas.core.dtypes.common import (
     ensure_object,
@@ -508,22 +509,21 @@ def ensure_wrapped_if_datetimelike(arr):
 
 def sanitize_masked_array(data: ma.MaskedArray) -> np.ndarray:
     """
-    Convert numpy MaskedArray to ensure mask is softened.
+    Convert numpy MaskedArray to ensure mask is softened,
+
     """
     mask = ma.getmaskarray(data)
     if mask.any():
         dtype = cast(np.dtype, data.dtype)
-        data = ma.asarray(data.astype(dtype, copy=True))
-        data.soften_mask()  # set hardmask False if it was True
-
-        if np.issubdtype(dtype, np.integer):
-            fill_value: int | float | None = np.iinfo(dtype).min
-        elif np.issubdtype(dtype, np.floating):
-            fill_value = np.nan
+        if isinstance(dtype, ExtensionDtype) and dtype.name.startswith("Masked"):
+            data = ma.asarray(data.astype(dtype, copy=True))
+            data.soften_mask()  # If the data is a Masked EA, directly soften the mask.
         else:
-            fill_value = None
-
-        data[mask] = fill_value
+            dtype, fill_value = maybe_promote(data.dtype, np.nan)
+            dtype = cast(np.dtype, dtype)
+            data = ma.asarray(data.astype(dtype, copy=True))
+            data.soften_mask()  # set hardmask False if it was True
+            data[mask] = fill_value
     else:
         data = data.copy()
     return data