bpo-24538: Fix bug in shutil involving the copying of xattrs to read-only files. (PR-13212) (#13234)
Extended attributes can only be set on user-writeable files, but shutil previously
first chmod()ed the destination file to the source's permissions and then tried to
copy xattrs. This will cause failures if attempting to copy read-only files with
xattrs, as occurs with Git clones on Lustre FS.
(cherry picked from commit 79efbb719383386051c72f2ee932eeca8e033e6b)
Co-authored-by: Olexa Bilaniuk <obilaniu@users.noreply.github.com>
diff --git a/Lib/shutil.py b/Lib/shutil.py
index b0a53db..4c6fdd7 100644
--- a/Lib/shutil.py
+++ b/Lib/shutil.py
@@ -203,6 +203,9 @@
mode = stat.S_IMODE(st.st_mode)
lookup("utime")(dst, ns=(st.st_atime_ns, st.st_mtime_ns),
follow_symlinks=follow)
+ # We must copy extended attributes before the file is (potentially)
+ # chmod()'ed read-only, otherwise setxattr() will error with -EACCES.
+ _copyxattr(src, dst, follow_symlinks=follow)
try:
lookup("chmod")(dst, mode, follow_symlinks=follow)
except NotImplementedError:
@@ -226,7 +229,6 @@
break
else:
raise
- _copyxattr(src, dst, follow_symlinks=follow)
def copy(src, dst, *, follow_symlinks=True):
"""Copy data and mode bits ("cp src dst"). Return the file's destination.