https://github.com/python/cpython/commit/16d75675d2ad2454f6dfbf333c94e6237df... commit: 16d75675d2ad2454f6dfbf333c94e6237df36018 branch: master author: Victor Stinner <vstinner@python.org> committer: GitHub <noreply@github.com> date: 2020-04-01T00:27:18+02:00 summary: bpo-31160: Fix race condition in test_os.PtyTests (GH-19263) bpo-31160, bpo-40094: Wait until the process completes before closing the PTY to prevent sending SIGHUP to the child process. files: M Lib/test/test_builtin.py diff --git a/Lib/test/test_builtin.py b/Lib/test/test_builtin.py index 86e5f1dc0246e..eaada1b50439b 100644 --- a/Lib/test/test_builtin.py +++ b/Lib/test/test_builtin.py @@ -1846,6 +1846,7 @@ def run_child(self, child, terminal_input): os.close(w) self.skipTest("pty.fork() raised {}".format(e)) raise + if pid == 0: # Child try: @@ -1859,9 +1860,11 @@ def run_child(self, child, terminal_input): finally: # We don't want to return to unittest... os._exit(0) + # Parent os.close(w) os.write(fd, terminal_input) + # Get results from the pipe with open(r, "r") as rpipe: lines = [] @@ -1871,6 +1874,7 @@ def run_child(self, child, terminal_input): # The other end was closed => the child exited break lines.append(line) + # Check the result was got and corresponds to the user's terminal input if len(lines) != 2: # Something went wrong, try to get at stderr @@ -1888,11 +1892,14 @@ def run_child(self, child, terminal_input): child_output = child_output.decode("ascii", "ignore") self.fail("got %d lines in pipe but expected 2, child output was:\n%s" % (len(lines), child_output)) - os.close(fd) - # Wait until the child process completes + # Wait until the child process completes before closing the PTY to + # prevent sending SIGHUP to the child process. support.wait_process(pid, exitcode=0) + # Close the PTY + os.close(fd) + return lines def check_input_tty(self, prompt, terminal_input, stdio_encoding=None):