merge for issue #17358

Lib/imp.py

@@ -111,7 +111,12 @@ def load_source(name, pathname, file=None):
            'importlib.machinery.SourceFileLoader(name, pathname).load_module()'
            ' instead')
     warnings.warn(msg, DeprecationWarning, 2)
-    return _LoadSourceCompatibility(name, pathname, file).load_module(name)
+    _LoadSourceCompatibility(name, pathname, file).load_module(name)
+    module = sys.modules[name]
+    # To allow reloading to potentially work, use a non-hacked loader which
+    # won't rely on a now-closed file object.
+    module.__loader__ = _bootstrap.SourceFileLoader(name, pathname)
+    return module
 
 
 class _LoadCompiledCompatibility(_HackedGetData,
@@ -125,7 +130,12 @@ def load_compiled(name, pathname, file=None):
            'importlib.machinery.SourcelessFileLoader(name, pathname).'
            'load_module() instead ')
     warnings.warn(msg, DeprecationWarning, 2)
-    return _LoadCompiledCompatibility(name, pathname, file).load_module(name)
+    _LoadCompiledCompatibility(name, pathname, file).load_module(name)
+    module = sys.modules[name]
+    # To allow reloading to potentially work, use a non-hacked loader which
+    # won't rely on a now-closed file object.
+    module.__loader__ = _bootstrap.SourcelessFileLoader(name, pathname)
+    return module
 
 
 def load_package(name, path):

Misc/NEWS

@@ -52,6 +52,9 @@ Core and Builtins
 Library
 -------
 
+- Issue #17358: Modules loaded by imp.load_source() and load_compiled() (and by
+  extention load_module()) now have a better chance of working when reloaded.
+
 - Issue #17804: New function ``struct.iter_unpack`` allows for streaming
   struct unpacking.