Fix the MSDOS build

* config.bat:
* msdos/sedlisp.inp:
* msdos/sedlibmk.inp:
* msdos/sedleim.inp:
* msdos/sedadmin.inp:
* msdos/sed6.inp:
* msdos/sed3v2.inp:
* msdos/sed2v2.inp:
* msdos/sed1v2.inp: Adapt to Emacs 25.

* src/process.c (remove_slash_colon): Move out of "#ifdef
subprocesses" block, as it its called unconditionally.  Move
ADD_SUBFEATURE calls into "#ifdef subprocesses" block, as they
reference variables only defined in that block.
* src/msdos.h: Provide prototypes for IT_set_frame_parameters,
faccessat, msdos_fatal_signal, syms_of_msdos, pthread_sigmask,
dos_keysns, dos_keyread, run_msdos_command, and
syms_of_win16select, to avoid compiler warnings.
* src/msdos.c (SYS_ENVIRON): Define to either '_environ' or
'environ', depending on the DJGPP version.
Remove declarations of externally-visible Lisp objects, like
Qbackground_color and Qreverse.
(run_msdos_command): First argument is not signed, not unsigned.
Use SYS_ENVIRON.
(sys_select): Use 'timespec_cmp' instead of 'timespec_sign', as
the latter doesn't work when 'time_t' is an unsigned data type.
This caused idle timers to behave incorrectly: they only fired
after a keyboard input event.
* src/frame.c (adjust_frame_size) [MSDOS]: Account for
FRAME_TOP_MARGIN that isn't counted in the frame's number of
lines, but dos_set_window_size needs it to be added.
* src/lread.c (INFINITY, NAN) [DJGPP < 2.05]: Provide definitions.
* src/fns.c (sort_vector_copy) [__GNUC__ < 4]: Provide a prototype
that works around compilation errors with older GCC versions.
* src/w16select.c: Don't declare QCLIPBOARD and QPRIMARY as Lisp
Objects.
* src/filelock.c [MSDOS]: Ifdef away most of the code.  Provide
no-op implementations for 'lock_file' and 'unlock_file'.
(Ffile_locked_p) [MSDOS]: Always return nil.  This avoids multiple
ifdefs in all users of filelock.c functionality.
* src/conf_post.h (EOVERFLOW, SIZE_MAX) [DJGPP < 2.04]: Define.
* src/emacs.c [MSDOS]: Include dosfns.h, to avoid compiler
warnings.
* src/dosfns.h: Provide prototypes for dos_cleanup,
syms_of_dosfns, and init_dosfns.
* src/deps.mk (atimer.o): Depend on msdos.h.
(emacs.o): Depend on dosfns.h.
* src/atimer.c [MSDOS]: Include msdos.h, to avoid compiler
warnings.

* lisp/window.el (window--adjust-process-windows): Skip the body
if 'process-list' is not available.  This avoids failure to start
up on MS-DOS.
* lisp/vc/diff.el (diff-no-select): Test 'make-process', not
'start-process', as the latter is now available on all platforms.
* lisp/textmodes/ispell.el (ispell-async-processp): Replace
'start-process' with 'make-process' in a comment.
* lisp/term/internal.el (IT-unicode-translations): Modify and add
a few translations to display Info files with Unicode markup.  Fix
an ancient off-by-one mismatch error with Unicode codepoints.
* lisp/progmodes/compile.el (compilation-start): Test
'make-process', not 'start-process', as the latter is now
available on all platforms.
* lisp/man.el (Man-build-man-command, Man-getpage-in-background):
Test 'make-process', not 'start-process', as the latter is now
available on all platforms.
* lisp/international/mule-cmds.el (set-coding-system-map): Test
'make-process', not 'start-process', as the latter is now
available on all platforms.
* lisp/eshell/esh-cmd.el (eshell-do-pipelines-synchronously): Doc
fix.
(eshell-execute-pipeline): Test 'make-process', not
'start-process', as the latter is now available on all platforms.

1 files changed, 19 insertions, 17 deletions

diff --git a/src/msdos.c b/src/msdos.c
index 84e8c39ec0c..62411ea2f6d 100644
--- a/src/msdos.c
+++ b/src/msdos.c
@@ -59,6 +59,12 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 #include <libc/dosio.h>  /* for _USE_LFN */
 #include <conio.h>	 /* for cputs */
 
+#if (__DJGPP__ + (__DJGPP_MINOR__ > 3)) >= 3
+#define SYS_ENVIRON _environ
+#else
+#define SYS_ENVIRON environ
+#endif
+
 #include "msdos.h"
 #include "systime.h"
 #include "frame.h"
@@ -422,8 +428,6 @@ static unsigned long screen_old_address = 0;
 /* Segment and offset of the virtual screen.  If 0, DOS/V is NOT loaded.  */
 static unsigned short screen_virtual_segment = 0;
 static unsigned short screen_virtual_offset = 0;
-extern Lisp_Object Qcursor_type;
-extern Lisp_Object Qbar, Qhbar;
 
 /* The screen colors of the current frame, which serve as the default
    colors for newly-created frames.  */
@@ -1384,11 +1388,6 @@ IT_delete_glyphs (struct frame *f, int n)
 
 /* This was copied from xfaces.c  */
 
-extern Lisp_Object Qbackground_color;
-extern Lisp_Object Qforeground_color;
-Lisp_Object Qreverse;
-extern Lisp_Object Qtitle;
-
 /* IT_set_terminal_modes is called when emacs is started,
    resumed, and whenever the screen is redrawn!  */
 
@@ -3710,7 +3709,7 @@ dos_ttcooked (void)
    file TEMPOUT and stderr to TEMPERR.  */
 
 int
-run_msdos_command (unsigned char **argv, const char *working_dir,
+run_msdos_command (char **argv, const char *working_dir,
 		   int tempin, int tempout, int temperr, char **envv)
 {
   char *saveargv1, *saveargv2, *lowcase_argv0, *pa, *pl;
@@ -3796,8 +3795,8 @@ run_msdos_command (unsigned char **argv, const char *working_dir,
 	;
       if (*cmnd)
 	{
-	  extern char **environ;
-	  char **save_env = environ;
+	  extern char **SYS_ENVIRON;
+	  char **save_env = SYS_ENVIRON;
 	  int save_system_flags = __system_flags;
 
 	  /* Request the most powerful version of `system'.  We need
@@ -3809,16 +3808,16 @@ run_msdos_command (unsigned char **argv, const char *working_dir,
 			     | __system_handle_null_commands
 			     | __system_emulate_chdir);
 
-	  environ = envv;
+	  SYS_ENVIRON = envv;
 	  result = system (cmnd);
 	  __system_flags = save_system_flags;
-	  environ = save_env;
+	  SYS_ENVIRON = save_env;
 	}
       else
 	result = 0;	/* emulate Unixy shell behavior with empty cmd line */
     }
   else
-    result = spawnve (P_WAIT, argv[0], (char **)argv, envv);
+    result = spawnve (P_WAIT, argv[0], argv, envv);
 
   dup2 (inbak, 0);
   dup2 (outbak, 1);
@@ -4085,11 +4084,14 @@ sys_select (int nfds, fd_set *rfds, fd_set *wfds, fd_set *efds,
 	  gettime (&t);
 	  clnow = make_timespec (t.tv_sec, t.tv_nsec);
 	  cldiff = timespec_sub (clnow, cllast);
+	  /* Stop when timeout value is about to cross zero.  */
+	  if (timespec_cmp (*timeout, cldiff) <= 0)
+	    {
+	      timeout->tv_sec = 0;
+	      timeout->tv_nsec = 0;
+	      return 0;
+	    }
 	  *timeout = timespec_sub (*timeout, cldiff);
-
-	  /* Stop when timeout value crosses zero.  */
-	  if (timespec_sign (*timeout) <= 0)
-	    return 0;
 	  cllast = clnow;
 	  dos_yield_time_slice ();
 	}