--- lib/tempname.c_orig	2011-01-03 15:04:38 -0600
+++ lib/tempname.c	2012-09-29 00:47:34 -0500
@@ -172,7 +172,12 @@
       return -1;
     }
 
+#ifdef __VMS
+  /* No "/" required (or desired) on VMS. */
+  sprintf (tmpl, "%.*s%.*sXXXXXX", (int) dlen, dir, (int) plen, pfx);
+#else /* def __VMS */
   sprintf (tmpl, "%.*s/%.*sXXXXXX", (int) dlen, dir, (int) plen, pfx);
+#endif /* def __VMS [else] */
   return 0;
 }
 #endif /* _LIBC */
--- src/cmp.c_orig	2011-06-13 02:16:59 -0500
+++ src/cmp.c	2012-09-29 00:51:59 -0500
@@ -43,6 +43,12 @@
   proper_name_utf8 ("Torbjorn Granlund", "Torbj\303\266rn Granlund"), \
   proper_name ("David MacKenzie")
 
+#ifdef __VMS
+# define OPEN_ARG , "ctx = stm"
+#else /* def __VMS */
+# define OPEN_ARG
+#endif /* def __VMS [else] */
+
 #if defined LC_MESSAGES && ENABLE_NLS
 # define hard_locale_LC_MESSAGES hard_locale (LC_MESSAGES)
 #else
@@ -296,7 +302,7 @@
 	    xfreopen (NULL, "rb", stdin);
 	}
       else
-	file_desc[f1] = open (file[f1], O_RDONLY | O_BINARY, 0);
+	file_desc[f1] = open (file[f1], O_RDONLY | O_BINARY, 0 OPEN_ARG);
 
       if (file_desc[f1] < 0 || fstat (file_desc[f1], stat_buf + f1) != 0)
 	{
--- src/diff.c_orig	2011-08-15 00:24:38 -0500
+++ src/diff.c	2012-09-29 00:53:26 -0500
@@ -286,6 +286,14 @@
   re_set_syntax (RE_SYNTAX_GREP | RE_NO_POSIX_BACKTRACKING);
   excluded = new_exclude ();
 
+#ifdef __VMS
+  /* Set the default ignore_file_name_case value according to the
+   * current SET PROCESS /CASE_LOOKUP setting.  Override this default
+   * with an explicit --[no-]ignore-file-name-case option.
+   */
+  ignore_file_name_case = vms_case_blind();
+#endif /* def __VMS */
+
   /* Decode the options.  */
 
   while ((c = getopt_long (argc, argv, shortopts, longopts, NULL)) != -1)
--- src/diff3.c_orig	2011-07-03 15:42:54 -0500
+++ src/diff3.c	2012-09-29 01:00:52 -0500
@@ -1184,10 +1184,23 @@
   if (pipe (fds) != 0)
     perror_with_exit ("pipe");
 
+#  ifdef __VMS
+  if (decc$set_child_standard_streams( fds[ 0], fds[ 1], -1) < 0)
+    perror_with_exit ("decc$set_child_standard_streams");
+#  endif /* def __VMS */
+
   pid = fork ();
   if (pid == 0)
     {
       /* Child */
+#  ifdef __VMS
+      if (execv (diff_program, (char **) argv) < 0)
+        {
+          char msg[ 8+ 2048] = "execv";
+          strcpy( msg, diff_program);
+          perror_with_exit (msg);
+        }
+#  else /* def __VMS */
       close (fds[0]);
       if (fds[1] != STDOUT_FILENO)
 	{
@@ -1200,15 +1213,19 @@
       execvp (diff_program, (char **) argv);
 
       _exit (errno == ENOENT ? 127 : 126);
+#  endif /* def __VMS [else] */
     }
 
   if (pid == -1)
     perror_with_exit ("fork");
 
+#  ifndef __VMS
   close (fds[1]);		/* Prevent erroneous lack of EOF */
+#  endif /* ndef __VMS */
+
   fd = fds[0];
 
-#else
+#else /* HAVE_WORKING_FORK */
 
   FILE *fpipe;
   char const args[] = " --horizon-lines=100 -- ";
@@ -1243,7 +1260,7 @@
   free (command);
   fd = fileno (fpipe);
 
-#endif
+#endif /* HAVE_WORKING_FORK [else] */
 
   if (fstat (fd, &pipestat) != 0)
     perror_with_exit ("fstat");
@@ -1279,14 +1296,19 @@
   if (wstatus == -1)
     werrno = errno;
 
-#else
+#else /* ! HAVE_WORKING_FORK */
 
   if (close (fd) != 0)
     perror_with_exit ("close");
   if (waitpid (pid, &wstatus, 0) < 0)
     perror_with_exit ("waitpid");
 
-#endif
+#  ifdef __VMS
+  if (close (fds[ 1]) != 0)             /* Not closed above. */
+    perror_with_exit ("close");
+#  endif /* def __VMS */
+
+#endif /* ! HAVE_WORKING_FORK [else] */
 
   status = ! werrno && WIFEXITED (wstatus) ? WEXITSTATUS (wstatus) : INT_MAX;
 
--- src/ifdef.c_orig	2011-06-12 04:13:28 -0500
+++ src/ifdef.c	2012-09-28 20:05:07 -0500
@@ -152,7 +152,7 @@
 		  else
 		    {
 		      value[i] = groups_letter_value (groups, *f);
-		      if (value[i] == -1)
+		      if (value[i] == (uintmax_t)-1)
 			goto bad_format;
 		      f++;
 		    }
--- src/sdiff.c_orig	2011-08-15 00:24:38 -0500
+++ src/sdiff.c	2012-10-08 17:30:29 -0500
@@ -85,6 +85,9 @@
 #endif
 #ifdef SIGPIPE
        SIGPIPE,
+# ifdef __VMS
+#  define handler_index_of_SIGPIPE (NUM_SIGS - 2)
+# endif /* def __VMS */
 #endif
        SIGINT
 #define handler_index_of_SIGINT (NUM_SIGS - 1)
@@ -299,7 +302,15 @@
 static size_t
 ck_fread (char *buf, size_t size, FILE *f)
 {
-  size_t r = fread (buf, sizeof (char), size, f);
+  size_t r;
+
+#ifdef __VMS
+  /* Not classy, but it seems to do better than nothing. */
+  if (feof( f))
+    return 0;
+#endif /* def __VMS */
+
+  r = fread (buf, sizeof (char), size, f);
   if (r == 0 && ferror (f))
     perror_fatal (_("read failed"));
   return r;
@@ -588,6 +599,8 @@
       bool leftdir = diraccess (argv[optind]);
       bool rightdir = diraccess (argv[optind + 1]);
 
+      int diff_fds[2];
+
       if (leftdir & rightdir)
 	fatal ("both files to be compared are directories");
 
@@ -628,11 +641,28 @@
       }
 #else
       {
-	int diff_fds[2];
-
+# ifdef __VMS /* Was: #if HAVE_WORKING_VFORK */
+	sigset_t procmask;
+	sigset_t blocked;
+# endif /* def __VMS  Was: #if HAVE_WORKING_VFORK */
+      
 	if (pipe (diff_fds) != 0)
 	  perror_fatal ("pipe");
 
+# ifdef __VMS /* Was: #if HAVE_WORKING_VFORK */
+	/* Block SIGINT and SIGPIPE.  */
+	sigemptyset (&blocked);
+	sigaddset (&blocked, SIGINT);
+	sigaddset (&blocked, SIGPIPE);
+	sigprocmask (SIG_BLOCK, &blocked, &procmask);
+# endif /* def __VMS  Was: #if HAVE_WORKING_VFORK */
+
+#  ifdef __VMS
+        if (decc$set_child_standard_streams(
+         diff_fds[ 0], diff_fds[ 1], -1) <  0)
+          perror_fatal ("decc$set_child_standard_streams");
+#  endif /* def __VMS */
+
 	diffpid = fork ();
 	if (diffpid < 0)
 	  perror_fatal ("fork");
@@ -645,6 +675,21 @@
 	    if (initial_handler (handler_index_of_SIGINT) != SIG_IGN)
 	      signal_handler (SIGINT, SIG_IGN);
 	    signal_handler (SIGPIPE, SIG_DFL);
+# ifdef __VMS /* Was: #if HAVE_WORKING_VFORK */
+	    /* Stop blocking SIGINT and SIGPIPE in the child.  */
+	    sigprocmask (SIG_SETMASK, &procmask, 0);
+# endif /* def __VMS  Was: #if HAVE_WORKING_VFORK */
+# ifdef __VMS
+            /* Use a logical name in the definition of the "diff"
+             * command to locate the executable, and execv() to run it.
+             */
+            if (execv (diffargv[0], (char **) diffargv) < 0)
+              {
+                char msg[ 8+ 2048] = "execv";
+                strcpy( msg, diffargv[0]);
+                perror_fatal (msg);
+              }
+# else /* def __VMS */
 	    close (diff_fds[0]);
 	    if (diff_fds[1] != STDOUT_FILENO)
 	      {
@@ -654,9 +699,25 @@
 
 	    execvp (diffargv[0], (char **) diffargv);
 	    _exit (errno == ENOENT ? 127 : 126);
+# endif /* def __VMS [else] */
 	  }
 
-	close (diff_fds[1]);
+# ifdef __VMS /* Was: #if HAVE_WORKING_VFORK */
+	/* Restore the parent's SIGINT and SIGPIPE behavior.  */
+	if (initial_handler (handler_index_of_SIGINT) != SIG_IGN)
+	  signal_handler (SIGINT, catchsig);
+	if (initial_handler (handler_index_of_SIGPIPE) != SIG_IGN)
+	  signal_handler (SIGPIPE, catchsig);
+	else
+	  signal_handler (SIGPIPE, SIG_IGN);
+
+	/* Stop blocking SIGINT and SIGPIPE in the parent.  */
+	sigprocmask (SIG_SETMASK, &procmask, 0);
+# endif /* def __VMS  Was: #if HAVE_WORKING_VFORK */
+
+# ifndef __VMS
+	close (diff_fds[1]);            /* Closed later on VMS. */
+# endif /* ndef __VMS */
 	diffout = fdopen (diff_fds[0], "r");
 	if (! diffout)
 	  perror_fatal ("fdopen");
@@ -691,6 +752,11 @@
 	diffpid = 0;
 #endif
 
+# ifdef __VMS
+        if (close (diff_fds[ 1]) != 0)  /* Not closed above on VMS. */
+          perror_fatal ("close");
+# endif /* def __VMS */
+
 	if (tmpname)
 	  {
 	    unlink (tmpname);
@@ -824,7 +890,14 @@
 static void
 give_help (void)
 {
-  fprintf (stderr, "%s", _("\
+  fprintf (stderr,
+#ifdef __VMS
+  /* Carriage control differs on VMS. */
+   "%s\n",
+#else /* def __VMS */
+   "%s",
+#endif /* def __VMS [else] */
+   _("\
 ed:\tEdit then use both versions, each decorated with a header.\n\
 eb:\tEdit then use both versions.\n\
 el or e1:\tEdit then use the left version.\n\
@@ -960,7 +1033,20 @@
 	    int fd;
 
 	    if (tmpname)
-	      tmp = fopen (tmpname, "w");
+	      {
+#ifdef __VMS
+		/* 2012-10-08 SMS.
+		 * On VMS, fopen() with "w" will create a new version of
+		 * an existing file, and the overwrite mode ("r+")
+		 * allows old data to corrupt the new, so it's easiest
+		 * simply to delete any old file before opening a new
+		 * one.  Note that unlink() will be replaced by
+		 * vms_unlink() to deal with any multiple versions.
+		 */
+		unlink (tmpname);
+#endif /* def __VMS */
+		tmp = fopen (tmpname, "w");
+	      }
 	    else
 	      {
 		if ((fd = temporary_file ()) < 0)
@@ -1024,7 +1110,29 @@
 	      checksigs ();
 
 	      {
-#if ! HAVE_WORKING_FORK
+#if defined( __VMS)
+                /* Use system() to execute the "editor_program" with
+                 * "tmpname" as the (only) argument.
+                 */
+		char *command =
+		 xmalloc (strlen( editor_program) + 1 + strlen (tmpname) + 1);
+		sprintf (command, "%s %s", editor_program, tmpname);
+
+		wstatus = system (command);
+		if ((wstatus & STS$M_SEVERITY) == STS$K_SUCCESS)
+                  {
+                    /* Translate VMS success to UNIX success. */
+                    wstatus = 0;
+                  }
+                else
+                  {
+                    /* Stow the real VMS status away. */
+                    vaxc$errno = wstatus;
+                    /* Suggest use of the real VMS status. */
+		    werrno = EVMSERR;
+                  }
+		free (command);
+#elif ! HAVE_WORKING_FORK
 		char *command =
 		  xmalloc (shell_quote_length (editor_program)
 			   + 1 + strlen (tmpname) + 1);
@@ -1181,7 +1289,12 @@
   int e;
   sigset_t procmask;
   sigset_t blocked;
+#ifdef __VMS
+  /* No "/" required (or desired) on VMS. */
+  sprintf (buf, "%ssdiffXXXXXX", dir);
+#else /* def __VMS */
   sprintf (buf, "%s/sdiffXXXXXX", dir);
+#endif /* def __VMS [else] */
   sigemptyset (&blocked);
   sigaddset (&blocked, SIGINT);
   sigprocmask (SIG_BLOCK, &blocked, &procmask);