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 ();
         }