Enhance terpri to allow conditionally output a newline

* doc/lispref/streams.texi (Output Functions): Document new argument ENSURE to
terpri.

* doc/misc/cl.texi (Porting Common Lisp): Remove parse-integer.

* lisp/emacs-lisp/cl-extra.el (cl-fresh-line): New function.

* src/keymap.c (describe_vector_princ):
* src/keyboard.c (Fcommand_error_default_function): Adapt to change to
Fterpri.

* src/print.c (printchar_stdout_last): Declare.
(printchar): Record the last char written to stdout.
(Fterpri): Add optional argument ENSURE.

* test/automated/print-tests.el: New file.
(terpri): Tests for terpri.  (Bug#18652)

2 files changed, 11 insertions, 0 deletions

diff --git a/lisp/ChangeLog b/lisp/ChangeLog
index ef1bdfba0d6..87852d64a46 100644
--- a/lisp/ChangeLog
+++ b/lisp/ChangeLog
@@ -1,3 +1,7 @@
+2014-10-08  Leo Liu  <sdl.web@gmail.com>
+
+        * emacs-lisp/cl-extra.el (cl-fresh-line): New function.
+
 2014-10-08  Glenn Morris  <rgm@gnu.org>
 
         * calendar/cal-x.el (calendar-dedicate-diary):
diff --git a/lisp/emacs-lisp/cl-extra.el b/lisp/emacs-lisp/cl-extra.el
index e10844069ef..a7970261608 100644
--- a/lisp/emacs-lisp/cl-extra.el
+++ b/lisp/emacs-lisp/cl-extra.el
@@ -647,6 +647,13 @@ PROPLIST is a list of the sort returned by `symbol-plist'.
         (progn (setplist sym (cdr (cdr plist))) t)
       (cl--do-remf plist tag))))
 
+;;; Streams.
+
+;;;###autoload
+(defun cl-fresh-line (&optional stream)
+  "Output a newline unless already at the beginning of a line."
+  (terpri stream 'ensure))
+
 ;;; Some debugging aids.
 
 (defun cl-prettyprint (form)