--- make-temp-file.c~	2005-05-26 15:36:42.000000000 +0000
+++ make-temp-file.c	2005-05-28 19:00:54.000000000 +0000
@@ -50,6 +50,29 @@
 #define DIR_SEPARATOR '/'
 #endif
 
+#if defined (_WIN32) || defined (__MSDOS__) \
+    || defined (__DJGPP__) || defined (__OS2__)
+#  define HAVE_DOS_BASED_FILE_SYSTEM
+#  ifndef DIR_SEPARATOR_2 
+#    define DIR_SEPARATOR_2 '\\'
+#  endif
+#endif
+
+/* Define IS_DIR_SEPARATOR. VMS uses '::', ':', '[...]' and '<...>' to
+   separate the different components of a file specification.  It's a
+   bit of a stretch to call ':', ']' and '>' directory separators, so
+   just define the test to find the file name component.  */
+#ifdef VMS
+#  define IS_DIR_SEPARATOR(ch) ((ch) == ':' || (ch) == ']' || (ch) == '>')
+#else
+#  ifndef DIR_SEPARATOR_2
+#    define IS_DIR_SEPARATOR(ch) ((ch) == DIR_SEPARATOR)
+#  else
+#    define IS_DIR_SEPARATOR(ch) \
+	(((ch) == DIR_SEPARATOR) || ((ch) == DIR_SEPARATOR_2))
+#  endif
+#endif
+
 /* Name of temporary file.
    mktemp requires 6 trailing X's.  */
 #define TEMP_FILE "ccXXXXXX"
@@ -125,7 +148,8 @@
   len = strlen (base);
   tmpdir = XNEWVEC (char, len + 2);
   strcpy (tmpdir, base);
-  tmpdir[len] = DIR_SEPARATOR;
+  if (len>0 && !IS_DIR_SEPARATOR(tmpdir[len-1]))   
+      tmpdir[len] = DIR_SEPARATOR;
   tmpdir[len+1] = '\0';
 
   memoized_tmpdir = tmpdir;