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.

1 files changed, 39 insertions, 0 deletions

diff --git a/test/src/callproc-tests.el b/test/src/callproc-tests.el
new file mode 100644
index 00000000000..46541aba78c
--- /dev/null
+++ b/test/src/callproc-tests.el
@@ -0,0 +1,39 @@
+;;; callproc-tests.el --- callproc.c tests -*- lexical-binding: t -*-
+
+;; Copyright (C) 2016 Free Software Foundation, Inc.
+
+;; This file is part of GNU Emacs.
+
+;; GNU Emacs is free software: you can redistribute it and/or modify
+;; it under the terms of the GNU General Public License as published by
+;; the Free Software Foundation, either version 3 of the License, or
+;; (at your option) any later version.
+
+;; GNU Emacs is distributed in the hope that it will be useful,
+;; but WITHOUT ANY WARRANTY; without even the implied warranty of
+;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+;; GNU General Public License for more details.
+
+;; You should have received a copy of the GNU General Public License
+;; along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.
+
+;;; Code:
+
+(require 'ert)
+(eval-when-compile (require 'cl-lib))
+
+(ert-deftest initial-environment-preserved ()
+  "Check that `initial-environment' is not modified by Emacs (Bug #10980)."
+  (skip-unless (eq system-type 'windows-nt))
+  (cl-destructuring-bind (initial-shell shell)
+      (with-temp-buffer
+        (let ((process-environment (cons "SHELL" process-environment)))
+          (call-process (expand-file-name invocation-name invocation-directory)
+                        nil t nil
+                        "--batch" "-Q" "--eval"
+                        (prin1-to-string
+                         '(progn (prin1 (getenv-internal "SHELL" initial-environment))
+                                 (prin1 (getenv-internal "SHELL"))))))
+        (split-string-and-unquote (buffer-string)))
+    (should (equal initial-shell "nil"))
+    (should-not (equal initial-shell shell))))