Issue #21888: plistlib's load() and loads() now work if the fmt parameter is

specified.

Lib/plistlib.py

@@ -984,18 +984,16 @@ def load(fp, *, fmt=None, use_builtin_types=True, dict_type=dict):
         fp.seek(0)
         for info in _FORMATS.values():
             if info['detect'](header):
-                p = info['parser'](
-                    use_builtin_types=use_builtin_types,
-                    dict_type=dict_type,
-                )
+                P = info['parser']
                 break
 
         else:
             raise InvalidFileException()
 
     else:
-        p = _FORMATS[fmt]['parser'](use_builtin_types=use_builtin_types)
+        P = _FORMATS[fmt]['parser']
 
+    p = P(use_builtin_types=use_builtin_types, dict_type=dict_type)
     return p.parse(fp)
 
 

Lib/test/test_plistlib.py

@@ -207,6 +207,9 @@ class TestPlistlib(unittest.TestCase):
         for fmt in ALL_FORMATS:
             with self.subTest(fmt=fmt):
                 pl = self._create(fmt=fmt)
+                pl2 = plistlib.loads(TESTDATA[fmt], fmt=fmt)
+                self.assertEqual(dict(pl), dict(pl2),
+                    "generated data was not identical to Apple's output")
                 pl2 = plistlib.loads(TESTDATA[fmt])
                 self.assertEqual(dict(pl), dict(pl2),
                     "generated data was not identical to Apple's output")
@@ -217,6 +220,8 @@ class TestPlistlib(unittest.TestCase):
                 b = BytesIO()
                 pl = self._create(fmt=fmt)
                 plistlib.dump(pl, b, fmt=fmt)
+                pl2 = plistlib.load(BytesIO(b.getvalue()), fmt=fmt)
+                self.assertEqual(dict(pl), dict(pl2))
                 pl2 = plistlib.load(BytesIO(b.getvalue()))
                 self.assertEqual(dict(pl), dict(pl2))
 

Misc/NEWS

@@ -108,6 +108,9 @@ Core and Builtins
 Library
 -------
 
+- Issue #21888: plistlib's load() and loads() now work if the fmt parameter is
+  specified.
+
 - Issue #22032: __qualname__ instead of __name__ is now always used to format
   fully qualified class names of Python implemented classes.