Keep w32 environment settings internal only

* src/emacs.c (main) [WINDOWSNT]: Move init_environment calls after the
set_initial_environment call.  This prevents Emacs' modifications to the
environment from contaminating Vprocess_environment and
Vinitial_environment (Bug #10980).
* src/callproc.c (getenv_internal) [WINDOWSNT]: Consult Emacs' internal
environment in as a fallback to Vprocess_environment.
* test/src/callproc-tests.el (initial-environment-preserved): New Test.

2 files changed, 28 insertions, 10 deletions

diff --git a/src/callproc.c b/src/callproc.c
index 7008b916dad..e8d089cf20e 100644
--- a/src/callproc.c
+++ b/src/callproc.c
@@ -1375,6 +1375,20 @@ getenv_internal (const char *var, ptrdiff_t varlen, char **value,
                          Vprocess_environment))
     return *value ? 1 : 0;
 
+  /* On Windows we make some modifications to Emacs' enviroment
+     without recording them in Vprocess_environment.  */
+#ifdef WINDOWSNT
+  {
+    char* tmpval = getenv (var);
+    if (tmpval)
+      {
+        *value = tmpval;
+        *valuelen = strlen (tmpval);
+        return 1;
+      }
+  }
+#endif
+
   /* For DISPLAY try to get the values from the frame or the initial env.  */
   if (strcmp (var, "DISPLAY") == 0)
     {
diff --git a/src/emacs.c b/src/emacs.c
index b2219844ca0..fa7ec017fb5 100644
--- a/src/emacs.c
+++ b/src/emacs.c
@@ -1349,16 +1349,6 @@ Using an Emacs configured with --with-x-toolkit=lucid does not have this problem
   globals_of_gfilenotify ();
 #endif
 
-#ifdef WINDOWSNT
-  globals_of_w32 ();
-#ifdef HAVE_W32NOTIFY
-  globals_of_w32notify ();
-#endif
-  /* Initialize environment from registry settings.  */
-  init_environment (argv);
-  init_ntproc (dumping); /* must precede init_editfns.  */
-#endif
-
 #ifdef HAVE_NS
   /* Initialize the locale from user defaults.  */
   ns_init_locale ();
@@ -1375,6 +1365,20 @@ Using an Emacs configured with --with-x-toolkit=lucid does not have this problem
   if (! dumping)
     set_initial_environment ();
 
+#ifdef WINDOWSNT
+  globals_of_w32 ();
+#ifdef HAVE_W32NOTIFY
+  globals_of_w32notify ();
+#endif
+  /* Initialize environment from registry settings.  Make sure to do
+     this only after calling set_initial_environment so that
+     Vinitial_environment and Vprocess_environment will contain only
+     variables from the parent process without modifications from
+     Emacs.  */
+  init_environment (argv);
+  init_ntproc (dumping); /* must precede init_editfns.  */
+#endif
+
   /* AIX crashes are reported in system versions 3.2.3 and 3.2.4
      if this is not done.  Do it after set_global_environment so that we
      don't pollute Vglobal_environment.  */