Merge remote-tracking branch 'origin/master' into issue-104-cannot-exec-setuids

Conflicts:
	pexpect/__init__.py

5 files changed, 221 insertions, 41 deletions

diff --git a/tests/PexpectTestCase.py b/tests/PexpectTestCase.py
index 7a9574e..307437e 100644
--- a/tests/PexpectTestCase.py
+++ b/tests/PexpectTestCase.py
@@ -22,26 +22,68 @@ from __future__ import print_function
 
 import contextlib
 import unittest
+import signal
 import sys
 import os
 
+
 class PexpectTestCase(unittest.TestCase):
     def setUp(self):
         self.PYTHONBIN = sys.executable
         self.original_path = os.getcwd()
         tests_dir = os.path.dirname(__file__)
         self.project_dir = project_dir = os.path.dirname(tests_dir)
+
+        # all tests are executed in this folder; there are many auxiliary
+        # programs in this folder executed by spawn().
         os.chdir(tests_dir)
-        os.environ['COVERAGE_PROCESS_START'] = os.path.join(project_dir, '.coveragerc')
+
+        # If the pexpect raises an exception after fork(), but before
+        # exec(), our test runner *also* forks.  We prevent this by
+        # storing our pid and asserting equality on tearDown.
+        self.pid = os.getpid()
+
+        coverage_rc = os.path.join(project_dir, '.coveragerc')
+        os.environ['COVERAGE_PROCESS_START'] = coverage_rc
         os.environ['COVERAGE_FILE'] = os.path.join(project_dir, '.coverage')
         print('\n', self.id(), end=' ')
         sys.stdout.flush()
+
+        # some build agents will ignore SIGHUP and SIGINT, which python
+        # inherits.  This causes some of the tests related to terminate()
+        # to fail.  We set them to the default handlers that they should
+        # be, and restore them back to their SIG_IGN value on tearDown.
+        #
+        # I'm not entirely convinced they need to be restored, only our
+        # test runner is affected.
+        self.restore_ignored_signals = [
+            value for value in (signal.SIGHUP, signal.SIGINT,)
+            if signal.getsignal(value) == signal.SIG_IGN]
+        if signal.SIGHUP in self.restore_ignored_signals:
+            # sighup should be set to default handler
+            signal.signal(signal.SIGHUP, signal.SIG_DFL)
+        if signal.SIGINT in self.restore_ignored_signals:
+            # SIGINT should be set to signal.default_int_handler
+            signal.signal(signal.SIGINT, signal.default_int_handler)
         unittest.TestCase.setUp(self)
 
     def tearDown(self):
-        os.chdir (self.original_path)
+        # restore original working folder
+        os.chdir(self.original_path)
+
+        if self.pid != os.getpid():
+            # The build server pattern-matches phrase 'Test runner has forked!'
+            print("Test runner has forked! This means a child process raised "
+                  "an exception before exec() in a test case, the error is "
+                  "more than likely found above this line in stderr.",
+                  file=sys.stderr)
+            exit(1)
+
+        # restore signal handlers
+        for signal_value in self.restore_ignored_signals:
+            signal.signal(signal_value, signal.SIG_IGN)
 
-    if sys.version_info < (2,7):
+    if sys.version_info < (2, 7):
         # We want to use these methods, which are new/improved in 2.7, but
         # we are still supporting 2.6 for the moment. This section can be
         # removed when we drop Python 2.6 support.
diff --git a/tests/test_ctrl_chars.py b/tests/test_ctrl_chars.py
index 9c7b869..10d03db 100755
--- a/tests/test_ctrl_chars.py
+++ b/tests/test_ctrl_chars.py
@@ -26,6 +26,9 @@ from . import PexpectTestCase
 import time
 import sys
 
+from ptyprocess import ptyprocess
+ptyprocess._make_eof_intr()
+
 if sys.version_info[0] >= 3:
     def byte(i):
         return bytes([i])
@@ -54,7 +57,7 @@ class TestCtrlChars(PexpectTestCase.PexpectTestCase):
         child = pexpect.spawn('python getch.py', echo=False, timeout=5)
         child.expect('READY')
         child.sendintr()
-        child.expect(str(child._INTR) + '<STOP>')
+        child.expect(str(ord(ptyprocess._INTR)) + '<STOP>')
 
         child.send(byte(0))
         child.expect('0<STOP>')
@@ -66,7 +69,7 @@ class TestCtrlChars(PexpectTestCase.PexpectTestCase):
         child = pexpect.spawn('python getch.py', echo=False, timeout=5)
         child.expect('READY')
         child.sendeof()
-        child.expect(str(child._EOF) + '<STOP>')
+        child.expect(str(ord(ptyprocess._EOF)) + '<STOP>')
 
         child.send(byte(0))
         child.expect('0<STOP>')
diff --git a/tests/test_maxcanon.py b/tests/test_maxcanon.py
new file mode 100644
index 0000000..bbd08f3
--- /dev/null
+++ b/tests/test_maxcanon.py
@@ -0,0 +1,152 @@
+""" Module for canonical-mode tests. """
+import sys
+import os
+
+
+import pexpect
+from . import PexpectTestCase
+
+
+class TestCaseCanon(PexpectTestCase.PexpectTestCase):
+    """
+    Test expected Canonical mode behavior (limited input line length).
+
+    All systems use the value of MAX_CANON which can be found using
+    fpathconf(3) value PC_MAX_CANON -- with the exception of Linux.
+
+    Linux, though defining a value of 255, actually honors the value
+    of 4096 from linux kernel include file tty.h definition
+    N_TTY_BUF_SIZE.
+
+    Linux also does not honor IMAXBEL. termios(3) states, "Linux does not
+    implement this bit, and acts as if it is always set." Although these
+    tests ensure it is enabled, this is a non-op for Linux.
+
+    These tests only ensure the correctness of the behavior described by
+    the sendline() docstring. pexpect is not particularly involved in
+    these scenarios, though if we wish to expose some kind of interface
+    to tty.setraw, for example, these tests may be re-purposed as such.
+
+    Lastly, portions of these tests are skipped on Travis-CI. It produces
+    unexpected behavior not reproduced on Debian/GNU Linux.
+    """
+
+    def setUp(self):
+        super(TestCaseCanon, self).setUp()
+
+        self.echo = False
+        if sys.platform.lower().startswith('linux'):
+            # linux is 4096, N_TTY_BUF_SIZE.
+            self.max_input = 4096
+            self.echo = True
+        elif sys.platform.lower().startswith('sunos'):
+            # SunOS allows PC_MAX_CANON + 1; see
+            # https://bitbucket.org/illumos/illumos-gate/src/d07a59219ab7fd2a7f39eb47c46cf083c88e932f/usr/src/uts/common/io/ldterm.c?at=default#cl-1888
+            self.max_input = os.fpathconf(0, 'PC_MAX_CANON') + 1
+        else:
+            # All others (probably) limit exactly at PC_MAX_CANON
+            self.max_input = os.fpathconf(0, 'PC_MAX_CANON')
+
+    def test_under_max_canon(self):
+        " BEL is not sent by terminal driver at maximum bytes - 1. "
+        # given,
+        child = pexpect.spawn('bash', echo=self.echo, timeout=5)
+        child.sendline('echo READY')
+        child.sendline('stty icanon imaxbel')
+        child.sendline('echo BEGIN; cat')
+
+        # some systems BEL on (maximum - 1), not able to receive CR,
+        # even though all characters up until then were received, they
+        # simply cannot be transmitted, as CR is part of the transmission.
+        send_bytes = self.max_input - 1
+
+        # exercise,
+        child.sendline('_' * send_bytes)
+
+        # fast forward beyond 'cat' command, as ^G can be found as part of
+        # set-xterm-title sequence of $PROMPT_COMMAND or $PS1.
+        child.expect_exact('BEGIN')
+
+        # verify, all input is found in echo output,
+        child.expect_exact('_' * send_bytes)
+
+        # BEL is not found,
+        with self.assertRaises(pexpect.TIMEOUT, timeout=5):
+            child.expect_exact('\a')
+
+        # cleanup,
+        child.sendeof()           # exit cat(1)
+        child.sendline('exit 0')  # exit bash(1)
+        child.expect(pexpect.EOF)
+        assert not child.isalive()
+        assert child.exitstatus == 0
+
+    def test_beyond_max_icanon(self):
+        " a single BEL is sent when maximum bytes is reached. "
+        # given,
+        child = pexpect.spawn('bash', echo=self.echo, timeout=5)
+        child.sendline('stty icanon imaxbel erase ^H')
+        child.sendline('cat')
+        send_bytes = self.max_input
+
+        # exercise,
+        child.sendline('_' * send_bytes)
+        child.expect_exact('\a')
+
+        # exercise, we must now backspace to send CR.
+        child.sendcontrol('h')
+        child.sendline()
+
+        if os.environ.get('TRAVIS', None) == 'true':
+            # Travis-CI has intermittent behavior here, possibly
+            # because the master process is itself, a PTY?
+            return
+
+        # verify the length of (maximum - 1) received by cat(1),
+        # which has written it back out,
+        child.expect_exact('_' * (send_bytes - 1))
+        # and not a byte more.
+        with self.assertRaises(pexpect.TIMEOUT):
+            child.expect_exact('_', timeout=1)
+
+        # cleanup,
+        child.sendeof()           # exit cat(1)
+        child.sendline('exit 0')  # exit bash(1)
+        child.expect_exact(pexpect.EOF)
+        assert not child.isalive()
+        assert child.exitstatus == 0
+
+    def test_max_no_icanon(self):
+        " may exceed maximum input bytes if canonical mode is disabled. "
+        # given,
+        child = pexpect.spawn('bash', echo=self.echo, timeout=5)
+        child.sendline('stty -icanon imaxbel')
+        child.sendline('echo BEGIN; cat')
+        send_bytes = self.max_input + 11
+
+        # exercise,
+        child.sendline('_' * send_bytes)
+
+        # fast forward beyond 'cat' command, as ^G can be found as part of
+        # set-xterm-title sequence of $PROMPT_COMMAND or $PS1.
+        child.expect_exact('BEGIN')
+
+        if os.environ.get('TRAVIS', None) == 'true':
+            # Travis-CI has intermittent behavior here, possibly
+            # because the master process is itself, a PTY?
+            return
+
+        # BEL is *not* found,
+        with self.assertRaises(pexpect.TIMEOUT):
+            child.expect_exact('\a', timeout=1)
+
+        # verify, all input is found in output,
+        child.expect_exact('_' * send_bytes)
+
+        # cleanup,
+        child.sendcontrol('c')    # exit cat(1) (eof wont work in -icanon)
+        child.sendcontrol('c')
+        child.sendline('exit 0')  # exit bash(1)
+        child.expect(pexpect.EOF)
+        assert not child.isalive()
+        assert child.exitstatus == 0
diff --git a/tests/test_misc.py b/tests/test_misc.py
index a2245aa..28df570 100755
--- a/tests/test_misc.py
+++ b/tests/test_misc.py
@@ -149,41 +149,24 @@ class TestCaseMisc(PexpectTestCase.PexpectTestCase):
 
     def test_sighup(self):
         " validate argument `ignore_sighup=True` and `ignore_sighup=False`. "
-        # If a parent process sets an Ignore handler for SIGHUP (as on Fedora's
-        # build machines), this test breaks. We temporarily restore the default
-        # handler, so the child process will quit. However, we can't simply
-        # replace any installed handler, because getsignal returns None for
-        # handlers not set in Python code, so we wouldn't be able to restore
-        # them.
-        if signal.getsignal(signal.SIGHUP) == signal.SIG_IGN:
-            signal.signal(signal.SIGHUP, signal.SIG_DFL)
-            restore_sig_ign = True
-        else:
-            restore_sig_ign = False
-
         getch = sys.executable + ' getch.py'
-        try:
-            child = pexpect.spawn(getch, ignore_sighup=True)
-            child.expect('READY')
-            child.kill(signal.SIGHUP)
-            for _ in range(10):
-                if not child.isalive():
-                    self.fail('Child process should not have exited.')
-                time.sleep(0.1)
-
-            child = pexpect.spawn(getch, ignore_sighup=False)
-            child.expect('READY')
-            child.kill(signal.SIGHUP)
-            for _ in range(10):
-                if not child.isalive():
-                    break
-                time.sleep(0.1)
-            else:
-                self.fail('Child process should have exited.')
-
-        finally:
-            if restore_sig_ign:
-                signal.signal(signal.SIGHUP, signal.SIG_IGN)
+        child = pexpect.spawn(getch, ignore_sighup=True)
+        child.expect('READY')
+        child.kill(signal.SIGHUP)
+        for _ in range(10):
+            if not child.isalive():
+                self.fail('Child process should not have exited.')
+            time.sleep(0.1)
+
+        child = pexpect.spawn(getch, ignore_sighup=False)
+        child.expect('READY')
+        child.kill(signal.SIGHUP)
+        for _ in range(10):
+            if not child.isalive():
+                break
+            time.sleep(0.1)
+        else:
+            self.fail('Child process should have exited.')
 
     def test_bad_child_pid(self):
         " assert bad condition error in isalive(). "
@@ -191,7 +174,7 @@ class TestCaseMisc(PexpectTestCase.PexpectTestCase):
         child = pexpect.spawn('cat')
         child.terminate(force=1)
         # Force an invalid state to test isalive
-        child.terminated = 0
+        child.ptyproc.terminated = 0
         try:
             with self.assertRaisesRegexp(pexpect.ExceptionPexpect,
                                          ".*" + expect_errmsg):
diff --git a/tests/test_replwrap.py b/tests/test_replwrap.py
index 14f7c39..28c7599 100644
--- a/tests/test_replwrap.py
+++ b/tests/test_replwrap.py
@@ -26,7 +26,7 @@ class REPLWrapTestCase(unittest.TestCase):
         assert 'real' in res, res
 
         # PAGER should be set to cat, otherwise man hangs
-        res = bash.run_command('man sleep', timeout=2)
+        res = bash.run_command('man sleep', timeout=5)
         assert 'SLEEP' in res, res
 
     def test_multiline(self):