Preserve symlinks when writing .config.old files

if .config is a symlink, then the intention is probably to overwrite the
target, but rename()ing the symlink to .config.old interferes with that.

Use the shutil.copyfile() fallback instead if .config is a symlink.

1 files changed, 4 insertions, 2 deletions

diff --git a/kconfiglib.py b/kconfiglib.py
index a376d62..551bca9 100644
--- a/kconfiglib.py
+++ b/kconfiglib.py
@@ -5870,9 +5870,11 @@ def _save_old(path):
         basename = "." + basename + ".old"
     backup = os.path.join(dirname, basename)
 
+    # os.replace() would be nice here, but it's Python 3 (3.3+) only
     try:
-        # os.replace() would be nice here, but it's Python 3 (3.3+) only
-        if os.name == "posix":
+        # Use copyfile() if 'path' is a symlink. The intention is probably to
+        # overwrite the target in that case.
+        if os.name == "posix" and not os.path.islink(path):
             # Will remove .<filename>.old if it already exists on POSIX
             # systems
             os.rename(path, backup)