Prevent name clashes between CL structures and builtin types

* lisp/emacs-lisp/cl-preloaded.el (cl-struct-define): Don't allow
structures with the same names as builtin types.
(cl--typeof-types, cl--all-builtin-types): Move from cl-generic.el and
rename.
(cl--struct-name-p): New helper function.

* lisp/emacs-lisp/cl-macs.el (cl-defstruct): Don't allow structures
with the same names as builtin types.

* lisp/emacs-lisp/cl-generic.el (cl--generic-typeof-generalizer)
(cl-generic-generalizers): Adapt to name change.

* test/lisp/emacs-lisp/cl-macs-tests.el (cl-defstruct/builtin-type):
* test/lisp/emacs-lisp/cl-preloaded-tests.el
(cl-struct-define/builtin-type): New unit tests.

* etc/NEWS: Document changed behavior.

1 files changed, 33 insertions, 0 deletions

diff --git a/test/lisp/emacs-lisp/cl-preloaded-tests.el b/test/lisp/emacs-lisp/cl-preloaded-tests.el
new file mode 100644
index 00000000000..008a6e629f5
--- /dev/null
+++ b/test/lisp/emacs-lisp/cl-preloaded-tests.el
@@ -0,0 +1,33 @@
+;;; cl-preloaded-tests.el --- unit tests for cl-preloaded.el  -*- lexical-binding: t; -*-
+
+;; Copyright (C) 2017 Free Software Foundation, Inc.
+;; Author: Philipp Stephani <phst@google.com>
+
+;; This file is part of GNU Emacs.
+
+;; This program 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.
+
+;; This program 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 this program.  If not, see <http://www.gnu.org/licenses/>.
+
+;;; Commentary:
+
+;; Unit tests for lisp/emacs-lisp/cl-preloaded.el.
+
+;;; Code:
+
+(ert-deftest cl-struct-define/builtin-type ()
+  (should-error
+   (cl-struct-define 'hash-table nil nil 'record nil nil
+                     'cl-preloaded-tests-tag 'cl-preloaded-tests nil)
+   :type 'wrong-type-argument))
+
+;;; cl-preloaded-tests.el ends here