Index: environ.cc
===================================================================
RCS file: /cvs/src/src/winsup/cygwin/environ.cc,v
retrieving revision 1.49
diff -u -p -2 -r1.49 environ.cc
--- environ.cc	2001/05/04 20:39:38	1.49
+++ environ.cc	2001/05/10 09:13:02
@@ -729,4 +729,22 @@ env_sort (const void *a, const void *b)
 }
 
+static char*
+append_to_winenv (char* winenvp, const char* str)
+{
+  int len = strlen (str);
+  memcpy (winenvp, str, len + 1);
+  return (winenvp + len + 1);
+}
+
+/* Keep this list in upper case and sorted */
+const char* forced_winenv_vars [] =
+  {
+    "SYSTEMDRIVE",
+    "SYSTEMROOT",
+    NULL
+  };
+
+#define FORCED_WINENV_SIZE (sizeof (forced_winenv_vars) / sizeof (forced_winenv_vars[0])) 
+
 /* Create a Windows-style environment block, i.e. a typical character buffer
    filled with null terminated strings, terminated by double null characters.
@@ -736,8 +754,17 @@ char * __stdcall
 winenv (const char * const *envp, int keep_posix)
 {
-  int len, n, tl;
+  int len, n, tl, cmp;
   const char * const *srcp;
+  const char * const *forced_srcp;
+  const char *native_srcp;
   const char * *dstp;
+  const char* native_env_ptr [FORCED_WINENV_SIZE];
+  const char* const *cygwin_env_ptr [FORCED_WINENV_SIZE];
+  char* p;
 
+  debug_printf ("envp %p, keep_posix %d", envp, keep_posix);
+
+  tl = 0;
+
   for (n = 0; envp[n]; n++)
     continue;
@@ -745,7 +772,5 @@ winenv (const char * const *envp, int ke
   const char *newenvp[n + 1];
 
-  debug_printf ("envp %p, keep_posix %d", envp, keep_posix);
-
-  for (tl = 0, srcp = envp, dstp = newenvp; *srcp; srcp++, dstp++)
+  for (srcp = envp, dstp = newenvp; *srcp; srcp++, dstp++)
     {
       len = strcspn (*srcp, "=") + 1;
@@ -756,5 +781,5 @@ winenv (const char * const *envp, int ke
       else
 	{
-	  char *p = (char *) alloca (strlen (conv->native) + 1);
+	  p = (char *) alloca (strlen (conv->native) + 1);
 	  strcpy (p, conv->native);
 	  *dstp = p;
@@ -763,5 +788,5 @@ winenv (const char * const *envp, int ke
       if ((*dstp)[0] == '!' && isdrive ((*dstp) + 1) && (*dstp)[3] == '=')
 	{
-	  char *p = (char *) alloca (strlen (*dstp) + 1);
+	  p = (char *) alloca (strlen (*dstp) + 1);
 	  strcpy (p, *dstp);
 	  *p = '=';
@@ -778,13 +803,61 @@ winenv (const char * const *envp, int ke
   qsort (newenvp, envlen, sizeof (char *), env_sort);
 
+  for (srcp = newenvp, forced_srcp = forced_winenv_vars, n = 0, len = strlen (*forced_srcp);
+       *srcp || *forced_srcp; )
+    {                                         
+      if (*srcp == 0)
+        cmp = -1;
+      else if (*forced_srcp == 0)
+        cmp = 1;
+      else
+        cmp = strncmp (*forced_srcp, *srcp, len);
+      if (cmp < 0)
+        {
+          /* forced variable not presen in envp. scan native environent for
+             its value, and remember pointer for later inclusion */
+          for (native_srcp = GetEnvironmentStrings ();
+               *native_srcp &&
+               ! strncasematch (*forced_srcp, native_srcp, len);
+               native_srcp += strlen (native_srcp) + 1)
+            /* do nothing */ ;
+          if (*native_srcp)
+            {
+              native_env_ptr [n] = native_srcp;
+              tl += strlen (native_srcp) + 1;
+            }
+          else
+            native_env_ptr [n] = 0;
+
+          cygwin_env_ptr [n] = srcp;
+          n++;
+          forced_srcp++;
+          if (*forced_srcp)
+            len = strlen (*forced_srcp);
+        }
+      else if (cmp > 0)
+        srcp++;
+      else
+        {
+          srcp++;
+          forced_srcp++;
+          if (*forced_srcp)
+            len = strlen (*forced_srcp);
+        }
+    }
+  cygwin_env_ptr [n] = 0;
+
   /* Create an environment block suitable for passing to CreateProcess.  */
   char *ptr, *envblock;
   envblock = (char *) malloc (tl + 2);
-  for (srcp = newenvp, ptr = envblock; *srcp; srcp++)
+  for (n = 0, srcp = newenvp, ptr = envblock; *srcp; srcp++)
     {
-      len = strlen (*srcp);
-      memcpy (ptr, *srcp, len + 1);
-      ptr += len + 1;
+      for (; cygwin_env_ptr [n] == srcp; n++)
+        {
+          if (native_env_ptr [n] && *(native_env_ptr [n]))
+            ptr = append_to_winenv (ptr, native_env_ptr [n]);
+        }
+      ptr = append_to_winenv (ptr, *srcp);
     }
+
   *ptr = '\0';		/* Two null bytes at the end */