Make M-x shell work in emacs.

ports/emacs/nacl.patch

Index: ports/emacs/nacl.patch
diff --git a/ports/emacs/nacl.patch b/ports/emacs/nacl.patch
index 0c67369cd09f745255ca046c6088efb3cacf7741..84f74c9f3493750b08ac98efcbcdbb33e983f5e5 100644
--- a/ports/emacs/nacl.patch
+++ b/ports/emacs/nacl.patch
@@ -867,7 +867,19 @@ diff --git a/src/process.c b/src/process.c
  
  static void
  create_process (Lisp_Object process, char **new_argv, Lisp_Object current_dir)
-@@ -1663,9 +1684,13 @@ create_process (Lisp_Object process, char **new_argv, Lisp_Object current_dir)
+@@ -1640,7 +1661,11 @@ create_process (Lisp_Object process, char **new_argv, Lisp_Object current_dir)
+ #endif /* HAVE_PTYS */
+     {
+       int tem;
++#if defined(NACL_EMACS)
++      tem = nacl_spawn_pipe_flags (O_NONBLOCK, sv);
++#else
+       tem = pipe (sv);
++#endif
+       if (tem < 0)
+ 	report_file_error ("Creating pipe", Qnil);

[Pete Williamson, 2016/02/29 20:53:47]

Please double check indentation on this line.  The source file has a <tab> here,
just want to make sure the tab didn't get edited.  IT may be fine, but looking
at the diff in the alternate diff viewer (since the main diff viewer is broken
for nacl.patch), it seems that it should be indented two spaces more, but that
could just be the patch utility using a different default for number of spaces
in a tab (The emacs source uses 8 spaces to a tab.)

[bradnelson, 2016/03/03 18:04:02]

Done another pass to make these all match up in terms of local tabbing.

+       inchannel = sv[0];
+@@ -1663,9 +1688,13 @@ create_process (Lisp_Object process, char **new_argv, Lisp_Object current_dir)
        tem = pipe (wait_child_setup);
        if (tem < 0)
  	report_file_error ("Creating pipe", Qnil);
@@ -881,7 +893,35 @@ diff --git a/src/process.c b/src/process.c
        if (tem < 0)
  	{
  	  emacs_close (wait_child_setup[0]);
-@@ -4633,13 +4658,23 @@ wait_reading_process_output (intmax_t time_limit, int nsecs, int read_kbd,
+@@ -4473,14 +4502,26 @@ wait_reading_process_output (intmax_t time_limit, int nsecs, int read_kbd,
+ 	  Ctemp = write_mask;
+ 
+ 	  timeout = make_emacs_time (0, 0);
++#if defined (NACL_EMACS)
++    // NACL doesn't support pselect yet, so use select instead.
++    // (glibc stubs out pselect in terms of select).
++    // Select takes a different kind of time, and one fewer argument.
++    struct timeval timevalue = {0,0};
++	  if ((select (max (max_process_desc, max_input_desc) + 1,
++#else
+ 	  if ((pselect (max (max_process_desc, max_input_desc) + 1,
++#endif
+ 			&Atemp,
+ #ifdef NON_BLOCKING_CONNECT
+ 			(num_pending_connects > 0 ? &Ctemp : NULL),
+ #else
+ 			NULL,
+ #endif
+-			NULL, &timeout, NULL)
++#if defined (NACL_EMACS)
++             NULL, &timevalue)
++#else
++             NULL, &timeout, NULL)
++#endif
+ 	       <= 0))
+ 	    {
+ 	      /* It's okay for us to do this and then continue with
+@@ -4633,13 +4674,23 @@ wait_reading_process_output (intmax_t time_limit, int nsecs, int read_kbd,
            nfds = xg_select
  #elif defined (HAVE_NS)
  	  nfds = ns_select
@@ -905,6 +945,23 @@ diff --git a/src/process.c b/src/process.c
  
  #ifdef HAVE_GNUTLS
            /* GnuTLS buffers data internally.  In lowat mode it leaves
+@@ -6935,7 +6986,15 @@ wait_reading_process_output (intmax_t time_limit, int nsecs, int read_kbd,
+ 	{
+ 	  if (read_kbd || !NILP (wait_for_cell))
+ 	    FD_SET (0, &waitchannels);
+-	  nfds = pselect (1, &waitchannels, NULL, NULL, &timeout, NULL);
++#if defined (NACL_EMACS)
++    // NACL doesn't support pselect yet, so use select instead.
++    // (glibc stubs out pselect in terms of select).
++    // Select takes a different kind of time, and one fewer argument.
++    struct timeval timevalue = {0,0};
++    nfds = select(1, &waitchannels, NULL, NULL, &timevalue);
++#else
++	  nfds = pselect(1, &waitchannels, NULL, NULL, &timeout, NULL);
++#endif
+ 	}
+ 
+       xerrno = errno;
 diff --git a/src/sysdep.c b/src/sysdep.c
 --- a/src/sysdep.c
 +++ b/src/sysdep.c