bpo-32667: Fix tests when $PATH contains a file (#5322)

Some tests failed when the PATH environment variable contained a path
to an existing file. Fix tests to ignore also NotADirectoryError, not
only FileNotFoundError and PermissionError.

Lib/test/test_dtrace.py

@@ -79,7 +79,7 @@ class TraceBackend:
         try:
             output = self.trace(abspath("assert_usable" + self.EXTENSION))
             output = output.strip()
-        except (FileNotFoundError, PermissionError) as fnfe:
+        except (FileNotFoundError, NotADirectoryError, PermissionError) as fnfe:
             output = str(fnfe)
         if output != "probe: success":
             raise unittest.SkipTest(

Lib/test/test_subprocess.py

@@ -46,6 +46,8 @@ else:
     SETBINARY = ''
 
 NONEXISTING_CMD = ('nonexisting_i_hope',)
+# Ignore errors that indicate the command was not found
+NONEXISTING_ERRORS = (FileNotFoundError, NotADirectoryError, PermissionError)
 
 
 class BaseTestCase(unittest.TestCase):
@@ -306,9 +308,9 @@ class ProcessTestCase(BaseTestCase):
         # Verify first that the call succeeds without the executable arg.
         pre_args = [sys.executable, "-c"]
         self._assert_python(pre_args)
-        self.assertRaises((FileNotFoundError, PermissionError),
+        self.assertRaises(NONEXISTING_ERRORS,
                           self._assert_python, pre_args,
-                          executable="doesnotexist")
+                          executable=NONEXISTING_CMD[0])
 
     @unittest.skipIf(mswindows, "executable argument replaces shell")
     def test_executable_replaces_shell(self):
@@ -1146,13 +1148,10 @@ class ProcessTestCase(BaseTestCase):
         # value for that limit, but Windows has 2048, so we loop
         # 1024 times (each call leaked two fds).
         for i in range(1024):
-            with self.assertRaises(OSError) as c:
+            with self.assertRaises(NONEXISTING_ERRORS):
                 subprocess.Popen(NONEXISTING_CMD,
                                  stdout=subprocess.PIPE,
                                  stderr=subprocess.PIPE)
-            # ignore errors that indicate the command was not found
-            if c.exception.errno not in (errno.ENOENT, errno.EACCES):
-                raise c.exception
 
     def test_nonexisting_with_pipes(self):
         # bpo-30121: Popen with pipes must close properly pipes on error.
@@ -2533,7 +2532,7 @@ class POSIXProcessTestCase(BaseTestCase):
         # let some time for the process to exit, and create a new Popen: this
         # should trigger the wait() of p
         time.sleep(0.2)
-        with self.assertRaises(OSError) as c:
+        with self.assertRaises(OSError):
             with subprocess.Popen(NONEXISTING_CMD,
                                   stdout=subprocess.PIPE,
                                   stderr=subprocess.PIPE) as proc:
@@ -3044,7 +3043,7 @@ class ContextManagerTests(BaseTestCase):
             self.assertEqual(proc.returncode, 1)
 
     def test_invalid_args(self):
-        with self.assertRaises((FileNotFoundError, PermissionError)) as c:
+        with self.assertRaises(NONEXISTING_ERRORS):
             with subprocess.Popen(NONEXISTING_CMD,
                                   stdout=subprocess.PIPE,
                                   stderr=subprocess.PIPE) as proc: