Merge pull request #440 from lpirl/empty-pidfile

fix crash when stopping/restarting with an invalid pidfile

src/allmydata/scripts/startstop_node.py

@@ -185,7 +185,16 @@ def stop(config):
         return 2
     with open(pidfile, "r") as f:
         pid = f.read()
-    pid = int(pid)
+
+    try:
+        pid = int(pid)
+    except ValueError:
+        # The error message below mimics a Twisted error message, which is
+        # displayed when starting a node with an invalid pidfile.
+        print >>err, "Pidfile %s contains non-numeric value" % pidfile
+        # we define rc=2 to mean "nothing is running, but it wasn't me who
+        # stopped it"
+        return 2
 
     # kill it hard (SIGKILL), delete the twistd.pid file, then wait for the
     # process itself to go away. If it hasn't gone away after 20 seconds, warn

src/allmydata/test/cli/test_cli.py

@@ -7,6 +7,7 @@ import re
 from twisted.trial import unittest
 from twisted.python.monkey import MonkeyPatcher
 from twisted.internet import task
+from twisted.python.filepath import FilePath
 
 import allmydata
 from allmydata.util import fileutil, hashutil, base32, keyutil
@@ -1289,3 +1290,24 @@ class Options(ReallyEqualMixin, unittest.TestCase):
                               ["--node-directory=there", "start", "--nodaemon"])
         self.failUnlessRaises(usage.UsageError, self.parse,
                               ["start", "--basedir=here", "--nodaemon"])
+
+
+class Stop(unittest.TestCase):
+    def test_non_numeric_pid(self):
+        """
+        If the pidfile exists but does not contain a numeric value, a complaint to
+        this effect is written to stderr and the non-success result is
+        returned.
+        """
+        basedir = FilePath(self.mktemp().decode("ascii"))
+        basedir.makedirs()
+        basedir.child(u"twistd.pid").setContent(b"foo")
+
+        config = startstop_node.StopOptions()
+        config.stdout = StringIO()
+        config.stderr = StringIO()
+        config['basedir'] = basedir.path
+
+        result_code = startstop_node.stop(config)
+        self.assertEqual(2, result_code)
+        self.assertIn("contains non-numeric value", config.stderr.getvalue())