bug#31903: 27.0.50; Server sockets with :nowait no longer work

bug#31903: 27.0.50; Server sockets with :nowait no longer work

[Helmut Eller]

With a file test.el containing this code:

  (make-network-process :name "*test*"
                        :server t
                        :nowait t
                        :host 'local
                        :service t
                        :family 'ipv4)

and starting Emacs with: emacs -Q -batch -l test.el
prints:
  make server process failed: Success, :name, *test*, :server, t, :nowait, t, :host, local, :service, t, :family, ipv4

I'm not sure whether :nowait is supposed to work with server sockets,
but this used to work in Emacs 25.  Either way, the error message looks
pretty wrong.

elnode calls make-network-process[1] in a similar way, so it's quite
annoying that this has changed (and obviously no one tested elnode).

[1] https://github.com/nicferrier/elnode/blob/master/elnode.el


In GNU Emacs 27.0.50 (build 2, x86_64-pc-linux-gnu, GTK+ Version 3.22.11)
 of 2018-06-19 built on caladan
Repository revision: a9b720ac5030a4ca84e8ebe8436027da0468624c
Windowing system distributor 'The X.Org Foundation', version 11.0.11902000
System Description: Debian GNU/Linux 9 (stretch)

Configured using:
 'configure --with-xpm=no --with-gif=no --with-tiff=no --with-jpeg=no
 --without-pop'

Configured features:
PNG SOUND DBUS GSETTINGS NOTIFY GNUTLS LIBXML2 FREETYPE XFT ZLIB
TOOLKIT_SCROLL_BARS GTK3 X11 THREADS LIBSYSTEMD

bug#31903: 27.0.50; Server sockets with :nowait no longer work

[Noam Postavsky]

retitle 31903 26.1; make-network-process :server t signals error with :nowait t instead of ignoring it
found 31903 26.1
tags 31903 + confirmed
severity 31903 minor
quit

Helmut Eller <eller.helmut@gmail.com> writes:

> I'm not sure whether :nowait is supposed to work with server sockets,
> but this used to work in Emacs 25.  Either way, the error message looks
> pretty wrong.

As far as I can tell, Emacs 25 just ignores :nowait when :server is
passed.  We could change Emacs 26 do that as well, or we just make the
error official but give a more a sensible error message when passed both
:nowait and :server.

bug#31903: 27.0.50; Server sockets with :nowait no longer work

[Eli Zaretskii]

> From: Noam Postavsky <npostavs@gmail.com>
> Date: Sun, 01 Jul 2018 11:48:45 -0400
> Cc: Lars Ingebrigtsen <larsi@gnus.org>, 31903@debbugs.gnu.org
> 
> Helmut Eller <eller.helmut@gmail.com> writes:
> 
> > I'm not sure whether :nowait is supposed to work with server sockets,
> > but this used to work in Emacs 25.  Either way, the error message looks
> > pretty wrong.
> 
> As far as I can tell, Emacs 25 just ignores :nowait when :server is
> passed.  We could change Emacs 26 do that as well, or we just make the
> error official but give a more a sensible error message when passed both
> :nowait and :server.

Unless someone protests within the next few days, I think I prefer the
latter alternative.

Thanks.

bug#31903: 27.0.50; Server sockets with :nowait no longer work

[Noam Postavsky]

[-- Attachment #1: Type: text/plain, Size: 863 bytes --]

tags 31903 + patch
quit

Eli Zaretskii <eliz@gnu.org> writes:

>> From: Noam Postavsky <npostavs@gmail.com>
>> Date: Sun, 01 Jul 2018 11:48:45 -0400
>> Cc: Lars Ingebrigtsen <larsi@gnus.org>, 31903@debbugs.gnu.org
>> 
>> Helmut Eller <eller.helmut@gmail.com> writes:
>> 
>> > I'm not sure whether :nowait is supposed to work with server sockets,
>> > but this used to work in Emacs 25.  Either way, the error message looks
>> > pretty wrong.
>> 
>> As far as I can tell, Emacs 25 just ignores :nowait when :server is
>> passed.  We could change Emacs 26 do that as well, or we just make the
>> error official but give a more a sensible error message when passed both
>> :nowait and :server.
>
> Unless someone protests within the next few days, I think I prefer the
> latter alternative.

Okay, here is the patch for that, I will push to emacs-26 in a few days.


[-- Warning: decoded text below may be mangled, UTF-8 assumed --]
[-- Attachment #2: patch --]
[-- Type: text/x-diff, Size: 2747 bytes --]

From a2ec0e58ab979b0a64a097ff0880cb7509d8aced Mon Sep 17 00:00:00 2001
From: Noam Postavsky <npostavs@gmail.com>
Date: Thu, 5 Jul 2018 19:37:28 -0400
Subject: [PATCH v1] Explicitly reject :server and :nowait (Bug#31903)

* src/process.c (Fmake_network_process): Explicitly check for and
signal an error when passed both :server and :nowait non-nil.  In
Emacs 25, :nowait would be ignored in this case, but as of Emacs 26.1
this gives an error, albeit an unclear one.  Also remove obsolete
comment regarding configurations lacking non-blocking mode, the
corresponding code was removed in 2012-11-17 "Assume POSIX 1003.1-1988
or later for fcntl.h."
---
 src/process.c | 26 +++++++++++---------------
 1 file changed, 11 insertions(+), 15 deletions(-)

diff --git a/src/process.c b/src/process.c
index 7f6ea1261e..4d7a735652 100644
--- a/src/process.c
+++ b/src/process.c
@@ -3890,12 +3890,15 @@ failed) connections may be logged in the server process's buffer.
   filter = Fplist_get (contact, QCfilter);
   sentinel = Fplist_get (contact, QCsentinel);
   use_external_socket_p = Fplist_get (contact, QCuse_external_socket);
+  Lisp_Object server = Fplist_get (contact, QCserver);
+  bool nowait = !NILP (Fplist_get (contact, QCnowait));
 
+  if (!NILP (server) && nowait)
+    error ("`:server' is incompatible with `:nowait'");
   CHECK_STRING (name);
 
   /* :local ADDRESS or :remote ADDRESS */
-  tem = Fplist_get (contact, QCserver);
-  if (NILP (tem))
+  if (!NILP (server))
     address = Fplist_get (contact, QCremote);
   else
     address = Fplist_get (contact, QClocal);
@@ -4009,7 +4012,7 @@ failed) connections may be logged in the server process's buffer.
     }
 
 #ifdef HAVE_GETADDRINFO_A
-  if (!NILP (host) && !NILP (Fplist_get (contact, QCnowait)))
+  if (!NILP (host) && nowait)
     {
       ptrdiff_t hostlen = SBYTES (host);
       struct req
@@ -4154,20 +4157,13 @@ failed) connections may be logged in the server process's buffer.
 
   set_network_socket_coding_system (proc, host, service, name);
 
-  /* :server BOOL */
-  tem = Fplist_get (contact, QCserver);
-  if (!NILP (tem))
-    {
-      /* Don't support network sockets when non-blocking mode is
-	 not available, since a blocked Emacs is not useful.  */
-      p->is_server = true;
-      if (TYPE_RANGED_INTEGERP (int, tem))
-	p->backlog = XINT (tem);
-    }
+  /* :server QLEN */
+  p->is_server = !NILP (server);
+  if (TYPE_RANGED_INTEGERP (int, server))
+    p->backlog = XINT (server);
 
   /* :nowait BOOL */
-  if (!p->is_server && socktype != SOCK_DGRAM
-      && !NILP (Fplist_get (contact, QCnowait)))
+  if (!p->is_server && socktype != SOCK_DGRAM && nowait)
     p->is_non_blocking_client = true;
 
   bool postpone_connection = false;
-- 
2.11.0

bug#31903: 27.0.50; Server sockets with :nowait no longer work

[Noam Postavsky]

tags 31903 fixed
close 31903 26.2
quit

Noam Postavsky <npostavs@gmail.com> writes:


> Okay, here is the patch for that, I will push to emacs-26 in a few days.

Done.

[1: 90d95b000c]: 2018-07-09 19:39:03 -0400
  Explicitly reject :server and :nowait (Bug#31903)
  https://git.savannah.gnu.org/cgit/emacs.git/commit/?id=90d95b000c37f7e85096716db96c4a940436f387