parent: reap the child process if connection fails

For example if no response is received in :attr:`connect_timeout`
seconds, the child would be left running.

mitogen/parent.py

@@ -699,7 +699,11 @@ class Stream(mitogen.core.Stream):
         LOG.debug('%r.connect(): child process stdin/stdout=%r',
                   self, self.receive_side.fd)
 
-        self._connect_bootstrap(extra_fd)
+        try:
+            self._connect_bootstrap(extra_fd)
+        except Exception:
+            self._reap_child()
+            raise
 
     def _ec0_received(self):
         LOG.debug('%r._ec0_received()', self)

tests/data/python_never_responds.sh

@@ -0,0 +1,3 @@
+#!/bin/bash
+# I am a Python interpreter that sits idle until the connection times out.
+exec -a mitogen-tests-python-never-responds.sh sleep 86400

tests/parent_test.py

@@ -1,3 +1,4 @@
+import errno
 import os
 import subprocess
 import tempfile
@@ -9,6 +10,26 @@ import testlib
 import mitogen.parent
 
 
+class ReapChildTest(testlib.RouterMixin, testlib.TestCase):
+    def test_connect_timeout(self):
+        # Ensure the child process is reaped if the connection times out.
+        stream = mitogen.parent.Stream(
+            router=self.router,
+            remote_id=1234,
+            old_router=self.router,
+            max_message_size=self.router.max_message_size,
+            python_path=testlib.data_path('python_never_responds.sh'),
+            connect_timeout=0.5,
+        )
+        self.assertRaises(mitogen.core.TimeoutError,
+            lambda: stream.connect()
+        )
+        e = self.assertRaises(OSError,
+            lambda: os.kill(stream.pid, 0)
+        )
+        self.assertEquals(e.args[0], errno.ESRCH)
+
+
 class StreamErrorTest(testlib.RouterMixin, testlib.TestCase):
     def test_direct_eof(self):
         e = self.assertRaises(mitogen.core.StreamError,