[3.7] bpo-34260, shutil: fix copy2 and copystat documentation (GH-8523) (GH-10065)

Fix the documentation of copy2, as it does not copy file ownership (user and
group), only mode, mtime, atime and flags.

The original text was confusing to developers as it suggested that this
command is the same as 'cp -p', but according to cp(1), '-p' copies file
ownership as well.

Clarify which metadata is copied by shutil.copystat in its docstring.

(cherry picked from commit 4f399be0e70d8b5516b6213568b7665765bb3114)

diff --git a/Doc/library/shutil.rst b/Doc/library/shutil.rst
index 382f75d04f7134de91efeab92bb326c5ba91edd1..12e69a4ea040c038141971c9e4a0413d0118c66c 100644 (file)
--- a/Doc/library/shutil.rst
+++ b/Doc/library/shutil.rst
@@ -166,7 +166,7 @@ Directory and files operations
 .. function:: copy2(src, dst, *, follow_symlinks=True)
 
    Identical to :func:`~shutil.copy` except that :func:`copy2`
-   also attempts to preserve all file metadata.
+   also attempts to preserve file metadata.
 
    When *follow_symlinks* is false, and *src* is a symbolic
    link, :func:`copy2` attempts to copy all metadata from the

diff --git a/Lib/shutil.py b/Lib/shutil.py
index 3c02776a40655159ee47b45ce019c02eafb99681..f32c66b3550c91fe1b87251ebe4e3806f5484e88 100644 (file)
--- a/Lib/shutil.py
+++ b/Lib/shutil.py
@@ -171,11 +171,15 @@ else:
         pass
 
 def copystat(src, dst, *, follow_symlinks=True):
-    """Copy all stat info (mode bits, atime, mtime, flags) from src to dst.
+    """Copy file metadata
 
-    If the optional flag `follow_symlinks` is not set, symlinks aren't followed if and
-    only if both `src` and `dst` are symlinks.
+    Copy the permission bits, last access time, last modification time, and
+    flags from `src` to `dst`. On Linux, copystat() also copies the "extended
+    attributes" where possible. The file contents, owner, and group are
+    unaffected. `src` and `dst` are path names given as strings.
 
+    If the optional flag `follow_symlinks` is not set, symlinks aren't
+    followed if and only if both `src` and `dst` are symlinks.
     """
     def _nop(*args, ns=None, follow_symlinks=None):
         pass
@@ -243,8 +247,10 @@ def copy(src, dst, *, follow_symlinks=True):
     return dst
 
 def copy2(src, dst, *, follow_symlinks=True):
-    """Copy data and all stat info ("cp -p src dst"). Return the file's
-    destination."
+    """Copy data and metadata. Return the file's destination.
+
+    Metadata is copied with copystat(). Please see the copystat function
+    for more information.
 
     The destination may be a directory.