inotify: close most file descriptors when autostarting

Otherwise, operations that autostart while talking to an SSH repository
prevent SSH stderr from closing normally. This causes hangs at
the end of hg clone or hg pull -u.

hgext/inotify/server.py

@@ -708,6 +708,26 b' class Master(object):'
                 timeobj.handle_timeout()
 
 def start(ui, repo):
+    def closefds(ignore):
+        # (from python bug #1177468)
+        # close all inherited file descriptors
+        # Python 2.4.1 and later use /dev/urandom to seed the random module's RNG
+        # a file descriptor is kept internally as os._urandomfd (created on demand
+        # the first time os.urandom() is called), and should not be closed
+        try:
+            os.urandom(4)
+            urandom_fd = getattr(os, '_urandomfd', None)
+        except AttributeError:
+            urandom_fd = None
+        ignore.append(urandom_fd)
+        for fd in range(3, 256):
+            if fd in ignore:
+                continue
+            try:
+                os.close(fd)
+            except OSError:
+                pass
+
     m = Master(ui, repo)
     sys.stdout.flush()
     sys.stderr.flush()
@@ -716,6 +736,7 b' def start(ui, repo):'
     if pid:
         return pid
 
+    closefds([m.server.fileno(), m.watcher.fileno()])
     os.setsid()
 
     fd = os.open('/dev/null', os.O_RDONLY)