Close INotify filedescriptor if a directory is unwatched due to fs de…

…letion

INotify will transparently unwatch a directory if it has been deleted from
the filesystem. Not making a call to .loseConnection() results in
leaving permanently opened [orphaned] file descriptors.

We now close that file descriptor since it can no longer trigger.

src/twisted/internet/inotify.py

@@ -293,6 +293,7 @@ def _doRead(self, in_):
                     self._addChildren, self._watchpoints[new_wd])
             if mask & IN_DELETE_SELF:
                 self._rmWatch(wd)
+                self.loseConnection()
 
 
     def _addChildren(self, iwp):

src/twisted/internet/test/test_inotify.py

@@ -317,6 +317,38 @@ def _eb():
         return d
 
 
+    def test_deleteSelfLoseConnection(self):
+        """
+        L{inotify.INotify} closes the file descriptor after removing a
+        directory from the filesystem (and therefore from the watchlist).
+        """
+        def cbNotified(result):
+            def _():
+                try:
+                    self.assertFalse(self.inotify._isWatched(self.dirname))
+                    self.assertFalse(self.inotify.connected)
+                    d.callback(None)
+                except Exception:
+                    d.errback()
+
+            (ignored, filename, events) = result
+            self.assertEqual(filename.asBytesMode(), self.dirname.asBytesMode())
+            self.assertTrue(events & inotify.IN_DELETE_SELF)
+            reactor.callLater(0, _)
+
+        self.assertTrue(
+            self.inotify.watch(
+                self.dirname, mask=inotify.IN_DELETE_SELF,
+                callbacks=[lambda *args: notified.callback(args)]))
+
+        notified = defer.Deferred()
+        notified.addCallback(cbNotified)
+
+        self.dirname.remove()
+        d = defer.Deferred()
+        return d
+
+
     def test_ignoreDirectory(self):
         """
         L{inotify.INotify.ignore} removes a directory from the watchlist

src/twisted/newsfragments/9777.bugfix

@@ -0,0 +1 @@
+INotify will close its file descriptor if a directory is automatically removed by twisted from the watchlist because it's deleted, avoiding orphaned filedescriptors.