diff --git a/Doc/library/shutil.rst b/Doc/library/shutil.rst index 8ed7e9edb1c..d0191371971 100644 --- a/Doc/library/shutil.rst +++ b/Doc/library/shutil.rst @@ -52,7 +52,7 @@ Directory and files operations Copy the contents (no metadata) of the file named *src* to a file named *dst* and return *dst*. *dst* must be the complete target file name; look at :func:`shutil.copy` for a copy that accepts a target directory path. If - *src* and *dst* are the same files, :exc:`Error` is raised. + *src* and *dst* are the same files, :exc:`SameFileError` is raised. The destination location must be writable; otherwise, an :exc:`OSError` exception will be raised. If *dst* already exists, it will be replaced. Special files @@ -67,6 +67,16 @@ Directory and files operations :exc:`IOError` used to be raised instead of :exc:`OSError`. Added *follow_symlinks* argument. Now returns *dst*. + Raise :exc:`SameFileError` instead of :exc:`Error`. + + +.. exception:: SameFileError + + This exception is raised if source and destination in :func:`copyfile` + are the same file. + + .. versionadded:: 3.3 + .. function:: copymode(src, dst, *, follow_symlinks=True) diff --git a/Lib/shutil.py b/Lib/shutil.py index a8b9f3f4cbb..7db95993135 100644 --- a/Lib/shutil.py +++ b/Lib/shutil.py @@ -42,6 +42,9 @@ __all__ = ["copyfileobj", "copyfile", "copymode", "copystat", "copy", "copy2", class Error(EnvironmentError): pass +class SameFileError(Error): + """Raised when source and destination are the same file.""" + class SpecialFileError(EnvironmentError): """Raised when trying to do a kind of operation (e.g. copying) which is not supported on a special file (e.g. a named pipe)""" @@ -90,7 +93,7 @@ def copyfile(src, dst, *, follow_symlinks=True): """ if _samefile(src, dst): - raise Error("`%s` and `%s` are the same file" % (src, dst)) + raise SameFileError("{!r} and {!r} are the same file".format(src, dst)) for fn in [src, dst]: try: @@ -215,6 +218,9 @@ def copy(src, dst, *, follow_symlinks=True): If follow_symlinks is false, symlinks won't be followed. This resembles GNU's "cp -P src dst". + If source and destination are the same file, a SameFileError will be + raised. + """ if os.path.isdir(dst): dst = os.path.join(dst, os.path.basename(src)) diff --git a/Lib/test/test_shutil.py b/Lib/test/test_shutil.py index eb0e9a4ee7a..cbca767a4c3 100644 --- a/Lib/test/test_shutil.py +++ b/Lib/test/test_shutil.py @@ -18,7 +18,8 @@ from shutil import (_make_tarball, _make_zipfile, make_archive, register_archive_format, unregister_archive_format, get_archive_formats, Error, unpack_archive, register_unpack_format, RegistryError, - unregister_unpack_format, get_unpack_formats) + unregister_unpack_format, get_unpack_formats, + SameFileError) import tarfile import warnings @@ -688,7 +689,7 @@ class TestShutil(unittest.TestCase): with open(src, 'w') as f: f.write('cheddar') os.link(src, dst) - self.assertRaises(shutil.Error, shutil.copyfile, src, dst) + self.assertRaises(shutil.SameFileError, shutil.copyfile, src, dst) with open(src, 'r') as f: self.assertEqual(f.read(), 'cheddar') os.remove(dst) @@ -708,7 +709,7 @@ class TestShutil(unittest.TestCase): # to TESTFN/TESTFN/cheese, while it should point at # TESTFN/cheese. os.symlink('cheese', dst) - self.assertRaises(shutil.Error, shutil.copyfile, src, dst) + self.assertRaises(shutil.SameFileError, shutil.copyfile, src, dst) with open(src, 'r') as f: self.assertEqual(f.read(), 'cheddar') os.remove(dst) @@ -1215,6 +1216,14 @@ class TestShutil(unittest.TestCase): self.assertTrue(os.path.exists(rv)) self.assertEqual(read_file(src_file), read_file(dst_file)) + def test_copyfile_same_file(self): + # copyfile() should raise SameFileError if the source and destination + # are the same. + src_dir = self.mkdtemp() + src_file = os.path.join(src_dir, 'foo') + write_file(src_file, 'foo') + self.assertRaises(SameFileError, shutil.copyfile, src_file, src_file) + def test_copytree_return_value(self): # copytree returns its destination path. src_dir = self.mkdtemp() diff --git a/Misc/NEWS b/Misc/NEWS index ec9e3a6b2a8..35c4a44b405 100644 --- a/Misc/NEWS +++ b/Misc/NEWS @@ -44,6 +44,9 @@ Core and Builtins Library ------- +- Issue #1492704: shutil.copyfile() raises a distinct SameFileError now if + source and destination are the same file. Patch by Atsuo Ishimoto. + - Issue #15397: inspect.getmodulename() is now based directly on importlib via a new importlib.machinery.all_suffixes() API.