[Python-checkins] cpython (merge 3.2 -> 3.3): Fixes Issue #16114: The subprocess module no longer provides a
gregory.p.smith
python-checkins at python.org
Wed Oct 10 12:52:46 CEST 2012
http://hg.python.org/cpython/rev/ee30d7ef70be
changeset: 79633:ee30d7ef70be
branch: 3.3
parent: 79630:9451908da615
parent: 79632:e938fa6be509
user: Gregory P. Smith <greg at krypto.org>
date: Wed Oct 10 03:44:47 2012 -0700
summary:
Fixes Issue #16114: The subprocess module no longer provides a
misleading error message stating that args[0] did not exist when
either the cwd or executable keyword arguments specified a path that
did not exist.
files:
Lib/subprocess.py | 10 ++++-
Lib/test/test_subprocess.py | 47 +++++++++++++++++++++---
Misc/NEWS | 4 ++
Modules/_posixsubprocess.c | 7 +++-
4 files changed, 59 insertions(+), 9 deletions(-)
diff --git a/Lib/subprocess.py b/Lib/subprocess.py
--- a/Lib/subprocess.py
+++ b/Lib/subprocess.py
@@ -1327,6 +1327,7 @@
if executable is None:
executable = args[0]
+ orig_executable = executable
# For transferring possible exec failure from child to parent.
# Data format: "exception name:hex errno:description"
@@ -1409,10 +1410,17 @@
err_msg = err_msg.decode(errors="surrogatepass")
if issubclass(child_exception_type, OSError) and hex_errno:
errno_num = int(hex_errno, 16)
+ child_exec_never_called = (err_msg == "noexec")
+ if child_exec_never_called:
+ err_msg = ""
if errno_num != 0:
err_msg = os.strerror(errno_num)
if errno_num == errno.ENOENT:
- err_msg += ': ' + repr(args[0])
+ if child_exec_never_called:
+ # The error must be from chdir(cwd).
+ err_msg += ': ' + repr(cwd)
+ else:
+ err_msg += ': ' + repr(orig_executable)
raise child_exception_type(errno_num, err_msg)
raise child_exception_type(err_msg)
diff --git a/Lib/test/test_subprocess.py b/Lib/test/test_subprocess.py
--- a/Lib/test/test_subprocess.py
+++ b/Lib/test/test_subprocess.py
@@ -1038,24 +1038,30 @@
@unittest.skipIf(mswindows, "POSIX specific tests")
class POSIXProcessTestCase(BaseTestCase):
- def test_exceptions(self):
- nonexistent_dir = "/_this/pa.th/does/not/exist"
+ def setUp(self):
+ super().setUp()
+ self._nonexistent_dir = "/_this/pa.th/does/not/exist"
+
+ def _get_chdir_exception(self):
try:
- os.chdir(nonexistent_dir)
+ os.chdir(self._nonexistent_dir)
except OSError as e:
# This avoids hard coding the errno value or the OS perror()
# string and instead capture the exception that we want to see
# below for comparison.
desired_exception = e
- desired_exception.strerror += ': ' + repr(sys.executable)
+ desired_exception.strerror += ': ' + repr(self._nonexistent_dir)
else:
self.fail("chdir to nonexistant directory %s succeeded." %
- nonexistent_dir)
+ self._nonexistent_dir)
+ return desired_exception
- # Error in the child re-raised in the parent.
+ def test_exception_cwd(self):
+ """Test error in the child raised in the parent for a bad cwd."""
+ desired_exception = self._get_chdir_exception()
try:
p = subprocess.Popen([sys.executable, "-c", ""],
- cwd=nonexistent_dir)
+ cwd=self._nonexistent_dir)
except OSError as e:
# Test that the child process chdir failure actually makes
# it up to the parent process as the correct exception.
@@ -1064,6 +1070,33 @@
else:
self.fail("Expected OSError: %s" % desired_exception)
+ def test_exception_bad_executable(self):
+ """Test error in the child raised in the parent for a bad executable."""
+ desired_exception = self._get_chdir_exception()
+ try:
+ p = subprocess.Popen([sys.executable, "-c", ""],
+ executable=self._nonexistent_dir)
+ except OSError as e:
+ # Test that the child process exec failure actually makes
+ # it up to the parent process as the correct exception.
+ self.assertEqual(desired_exception.errno, e.errno)
+ self.assertEqual(desired_exception.strerror, e.strerror)
+ else:
+ self.fail("Expected OSError: %s" % desired_exception)
+
+ def test_exception_bad_args_0(self):
+ """Test error in the child raised in the parent for a bad args[0]."""
+ desired_exception = self._get_chdir_exception()
+ try:
+ p = subprocess.Popen([self._nonexistent_dir, "-c", ""])
+ except OSError as e:
+ # Test that the child process exec failure actually makes
+ # it up to the parent process as the correct exception.
+ self.assertEqual(desired_exception.errno, e.errno)
+ self.assertEqual(desired_exception.strerror, e.strerror)
+ else:
+ self.fail("Expected OSError: %s" % desired_exception)
+
def test_restore_signals(self):
# Code coverage for both values of restore_signals to make sure it
# at least does not blow up.
diff --git a/Misc/NEWS b/Misc/NEWS
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -37,6 +37,10 @@
Library
-------
+- Issue #16114: The subprocess module no longer provides a misleading error
+ message stating that args[0] did not exist when either the cwd or executable
+ keyword arguments specified a path that did not exist.
+
- Issue #16169: Fix ctypes.WinError()'s confusion between errno and winerror.
- Issue #16089: Allow ElementTree.TreeBuilder to work again with a non-Element
diff --git a/Modules/_posixsubprocess.c b/Modules/_posixsubprocess.c
--- a/Modules/_posixsubprocess.c
+++ b/Modules/_posixsubprocess.c
@@ -356,7 +356,7 @@
PyObject *preexec_fn,
PyObject *preexec_fn_args_tuple)
{
- int i, saved_errno, unused;
+ int i, saved_errno, unused, reached_preexec = 0;
PyObject *result;
const char* err_msg = "";
/* Buffer large enough to hold a hex integer. We can't malloc. */
@@ -440,6 +440,7 @@
POSIX_CALL(setsid());
#endif
+ reached_preexec = 1;
if (preexec_fn != Py_None && preexec_fn_args_tuple) {
/* This is where the user has asked us to deadlock their program. */
result = PyObject_Call(preexec_fn, preexec_fn_args_tuple, NULL);
@@ -489,6 +490,10 @@
}
unused = write(errpipe_write, cur, hex_errno + sizeof(hex_errno) - cur);
unused = write(errpipe_write, ":", 1);
+ if (!reached_preexec) {
+ /* Indicate to the parent that the error happened before exec(). */
+ unused = write(errpipe_write, "noexec", 6);
+ }
/* We can't call strerror(saved_errno). It is not async signal safe.
* The parent process will look the error message up. */
} else {
--
Repository URL: http://hg.python.org/cpython
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