Fixed io.acii read IPAC tables for long column types on Windows

astropy/io/ascii/ipac.py

@@ -14,6 +14,8 @@
 from textwrap import wrap
 from warnings import warn
 
+import numpy as np
+
 from astropy.table.pprint import get_auto_format_func
 from astropy.utils.exceptions import AstropyUserWarning
 
@@ -214,6 +216,10 @@ def get_cols(self, lines):
                 null = header_vals[3][i].strip()
                 fillval = "" if issubclass(col.type, core.StrType) else "0"
                 self.data.fill_values.append((null, fillval, col.name))
+            if "long".startswith(col.raw_type.lower()):
+                # ensure long columns are 64-bit int, to address:
+                # https://github.com/astropy/astropy/issues/15989
+                col.dtype = np.int64
             start = col.end + 1
             cols.append(col)
 

astropy/io/ascii/tests/test_types.py

@@ -53,6 +53,30 @@ def test_ipac_read_types():
         assert_equal(col.type, expected_type)
 
 
+def test_ipac_read_long_columns():
+    """Test for https://github.com/astropy/astropy/issues/15989"""
+    test_data = """\
+|              oid|expid|cadence|
+|             long|    l|    int|
+ 90000000000000001   123       1
+"""
+    dat = ascii.read(test_data, format="ipac")
+
+    # assert oid, as a long column, is at the minimal int64
+    oid = dat["oid"]
+    assert oid[0] == 90000000000000001
+    assert oid.dtype.kind == "i"
+    assert oid.dtype.itemsize >= 8
+
+    # expid is declared as a long column,
+    # the type needs to be at least int64, even though all
+    # the values are within int32 range
+    expid = dat["expid"]
+    assert expid[0] == 123
+    assert expid.dtype.kind == "i"
+    assert expid.dtype.itemsize >= 8
+
+
 def test_col_dtype_in_custom_class():
     """Test code in BaseOutputter._convert_vals to handle Column.dtype
     attribute. See discussion in #11895."""

docs/changes/io.ascii/15992.bugfix.rst

@@ -0,0 +1 @@
+Fixed reading IPAC tables for ``long`` column type on some platforms, e.g., Windows.