Issue #25583: Avoid incorrect errors raised by os.makedirs(exist_ok=True)

1 files changed, 5 insertions, 3 deletions

diff --git a/Lib/os.py b/Lib/os.py
index a8f6a0b..27b241a 100644
--- a/Lib/os.py
+++ b/Lib/os.py
@@ -226,7 +226,7 @@ def makedirs(name, mode=0o777, exist_ok=False):
         try:
             makedirs(head, mode, exist_ok)
         except FileExistsError:
-            # be happy if someone already created the path
+            # Defeats race condition when another thread created the path
             pass
         cdir = curdir
         if isinstance(tail, bytes):
@@ -235,8 +235,10 @@ def makedirs(name, mode=0o777, exist_ok=False):
             return
     try:
         mkdir(name, mode)
-    except OSError as e:
-        if not exist_ok or e.errno != errno.EEXIST or not path.isdir(name):
+    except OSError:
+        # Cannot rely on checking for EEXIST, since the operating system
+        # could give priority to other errors like EACCES or EROFS
+        if not exist_ok or not path.isdir(name):
             raise
 
 def removedirs(name):