Issue #17222: Raise FileExistsError when py_compile.compile would
overwrite a symlink or non-regular file with a regular file.
diff --git a/Lib/py_compile.py b/Lib/py_compile.py
index 701e8ac..cee35a5 100644
--- a/Lib/py_compile.py
+++ b/Lib/py_compile.py
@@ -7,6 +7,7 @@
import importlib._bootstrap
import importlib.machinery
import os
+import os.path
import sys
import traceback
@@ -96,12 +97,25 @@
See compileall.py for a script/module that uses this module to
byte-compile all installed files (or all files in selected
directories).
+
+ Do note that FileExistsError is raised if cfile ends up pointing at a
+ non-regular file or symlink. Because the compilation uses a file renaming,
+ the resulting file would be regular and thus not the same type of file as
+ it was previously.
"""
if cfile is None:
if optimize >= 0:
cfile = imp.cache_from_source(file, debug_override=not optimize)
else:
cfile = imp.cache_from_source(file)
+ if os.path.islink(cfile):
+ msg = ('{} is a symlink and will be changed into a regular file if '
+ 'import writes a byte-compiled file to it')
+ raise FileExistsError(msg.format(file, cfile))
+ elif os.path.exists(cfile) and not os.path.isfile(cfile):
+ msg = ('{} is a non-regular file and will be changed into a regular '
+ 'one if import writes a byte-compiled file to it')
+ raise FileExistsError(msg.format(file, cfile))
loader = importlib.machinery.SourceFileLoader('<py_compile>', file)
source_bytes = loader.get_data(file)
try: