* src/eval.c (Fprogn): Do not check that BODY is a proper list.

This undoes the previous change.  The check slows down the
interpreter, and is not needed to prevent a crash.  See
<http://lists.gnu.org/archive/html/emacs-devel/2013-07/msg00693.html>.
* doc/lispref/eval.texi (Special Forms): Mention 'lambda'.  Also, say that
non-well-formed expressions result in unspecified behavior, though
Emacs will not crash.

1 files changed, 0 insertions, 8 deletions

diff --git a/etc/NEWS b/etc/NEWS
index e7d51a4033a..facadac5c1c 100644
--- a/etc/NEWS
+++ b/etc/NEWS
@@ -538,14 +538,6 @@ file using `set-file-extended-attributes'.
 ** `visited-file-modtime' now returns -1 for nonexistent files.
 Formerly it returned a list (-1 LOW USEC PSEC), but this was ambiguous
 in the presence of files with negative time stamps.
-
-** Special forms with implied progn now check for proper lists.
-Starting in Emacs 21.4, a special form with an implied progn of an
-improper list ignored the trailing value, treating it as nil.  For
-example, (cond (t (message "hello") . "there")) ignored the "there".
-This inadvertent change to Emacs's behavior has been reverted, and
-Emacs now signals an error for these improper forms, as it did in
-version 21.3 and earlier.
 
 * Lisp Changes in Emacs 24.4