Issue #26385: Cleanup NamedTemporaryFile if fdopen() fails, by SilentGhost

Lib/tempfile.py

@@ -476,7 +476,8 @@ def NamedTemporaryFile(mode='w+b', bufsize=-1, suffix="",
     try:
         file = _os.fdopen(fd, mode, bufsize)
         return _TemporaryFileWrapper(file, name, delete)
-    except:
+    except BaseException:
+        _os.unlink(name)
         _os.close(fd)
         raise
 

Lib/test/test_tempfile.py

@@ -827,6 +827,13 @@ class test_NamedTemporaryFile(TC):
             os.close = old_close
             os.fdopen = old_fdopen
 
+    def test_bad_mode(self):
+        dir = tempfile.mkdtemp()
+        self.addCleanup(support.rmtree, dir)
+        with self.assertRaises(TypeError):
+            tempfile.NamedTemporaryFile(mode=(), dir=dir)
+        self.assertEqual(os.listdir(dir), [])
+
     # How to test the mode and bufsize parameters?
 
 test_classes.append(test_NamedTemporaryFile)

Misc/NEWS

@@ -55,6 +55,9 @@ Core and Builtins
 Library
 -------
 
+- Issue #26385: Remove the file if the internal fdopen() call in
+  NamedTemporaryFile() fails.  Based on patch by Silent Ghost.
+
 - Issue #26309: In the "socketserver" module, shut down the request (closing
   the connected socket) when verify_request() returns false.  Based on patch
   by Aviv Palivoda.