bpo-45558: shutil.copytree: Allow disabling copystat

Author: doronbehar

Doc/library/shutil.rst

@@ -226,16 +226,19 @@ Directory and files operations
 
 
 .. function:: copytree(src, dst, symlinks=False, ignore=None, \
-              copy_function=copy2, ignore_dangling_symlinks=False, \
-              dirs_exist_ok=False)
+              copy_stat=True, copy_function=copy2, \
+              ignore_dangling_symlinks=False, dirs_exist_ok=False)
 
    Recursively copy an entire directory tree rooted at *src* to a directory
    named *dst* and return the destination directory. *dirs_exist_ok* dictates
    whether to raise an exception in case *dst* or any missing parent directory
    already exists.
 
    Permissions and times of directories are copied with :func:`copystat`,
-   individual files are copied using :func:`~shutil.copy2`.
+   unless *copy_stat* is `False`. Individual files are copied using
+   :func:`~shutil.copy2` by default. Using `copy_stat=False` along with
+   `copy_function=shutil.copyfile` is useful when you wish to not use the
+   source permissions at all.
 
    If *symlinks* is true, symbolic links in the source tree are represented as
    symbolic links in the new tree and the metadata of the original links will

Lib/shutil.py

@@ -450,7 +450,7 @@ def _ignore_patterns(path, names):
     return _ignore_patterns
 
 def _copytree(entries, src, dst, symlinks, ignore, copy_function,
-              ignore_dangling_symlinks, dirs_exist_ok=False):
+              copy_stat, ignore_dangling_symlinks, dirs_exist_ok=False):
     if ignore is not None:
         ignored_names = ignore(os.fspath(src), [x.name for x in entries])
     else:
@@ -481,20 +481,22 @@ def _copytree(entries, src, dst, symlinks, ignore, copy_function,
                     # code with a custom `copy_function` may rely on copytree
                     # doing the right thing.
                     os.symlink(linkto, dstname)
-                    copystat(srcobj, dstname, follow_symlinks=not symlinks)
+                    if copy_stat:
+                        copystat(srcobj, dstname, follow_symlinks=not symlinks)
                 else:
                     # ignore dangling symlink if the flag is on
                     if not os.path.exists(linkto) and ignore_dangling_symlinks:
                         continue
                     # otherwise let the copy occur. copy2 will raise an error
                     if srcentry.is_dir():
                         copytree(srcobj, dstname, symlinks, ignore,
-                                 copy_function, dirs_exist_ok=dirs_exist_ok)
+                                 copy_function, copy_stat,
+                                 dirs_exist_ok=dirs_exist_ok)
                     else:
                         copy_function(srcobj, dstname)
             elif srcentry.is_dir():
                 copytree(srcobj, dstname, symlinks, ignore, copy_function,
-                         dirs_exist_ok=dirs_exist_ok)
+                         copy_stat, dirs_exist_ok=dirs_exist_ok)
             else:
                 # Will raise a SpecialFileError for unsupported file types
                 copy_function(srcobj, dstname)
@@ -504,18 +506,20 @@ def _copytree(entries, src, dst, symlinks, ignore, copy_function,
             errors.extend(err.args[0])
         except OSError as why:
             errors.append((srcname, dstname, str(why)))
-    try:
-        copystat(src, dst)
-    except OSError as why:
-        # Copying file access times may fail on Windows
-        if getattr(why, 'winerror', None) is None:
-            errors.append((src, dst, str(why)))
+    if copy_stat:
+        try:
+            copystat(src, dst)
+        except OSError as why:
+            # Copying file access times may fail on Windows
+            if getattr(why, 'winerror', None) is None:
+                errors.append((src, dst, str(why)))
     if errors:
         raise Error(errors)
     return dst
 
 def copytree(src, dst, symlinks=False, ignore=None, copy_function=copy2,
-             ignore_dangling_symlinks=False, dirs_exist_ok=False):
+             copy_stat=True, ignore_dangling_symlinks=False,
+             dirs_exist_ok=False):
     """Recursively copy a directory tree and return the destination directory.
 
     dirs_exist_ok dictates whether to raise an exception in case dst or any
@@ -551,12 +555,17 @@ def copytree(src, dst, symlinks=False, ignore=None, copy_function=copy2,
     destination path as arguments. By default, copy2() is used, but any
     function that supports the same signature (like copy()) can be used.
 
+    The optional copy_stat argument controls whether permissions will be
+    copied from the source to the destination. This can be used along with
+    copy_function=copyfile when you wish to not use the source permissions
+    at all.
     """
     sys.audit("shutil.copytree", src, dst)
     with os.scandir(src) as itr:
         entries = list(itr)
     return _copytree(entries=entries, src=src, dst=dst, symlinks=symlinks,
                      ignore=ignore, copy_function=copy_function,
+                     copy_stat=copy_stat,
                      ignore_dangling_symlinks=ignore_dangling_symlinks,
                      dirs_exist_ok=dirs_exist_ok)
 

Misc/NEWS.d/next/Library/2021-10-23-07-16-33.bpo-45558.jGmQIV.rst

@@ -0,0 +1 @@
+:func:`shutil.copytree`: Add a ``copy_stat`` boolean option that controls whether permissions will be copied as well from the source directory.