bug#6490: 24.0.50; src/lread.c: old style backquote bug?

[Makoto Fujiwara <makoto@ki.nu>]

first of all, I got the very much similar problem with
hnf-mode (2.5)
  http://nijino.homelinux.net/hnf-mode/

And the patch by Okazaki San fixed my problem. Thank you.

  I have looked at the patch, and minimized the changes in
diff wise.  It is logically exactly the same as the first
patch.

  This second patch also fixes my problem. If you look at this
patch, the changes almost nothing to the human being (just not
modifying char c).

diff --git a/src/lread.c b/src/lread.c
index c73f7f3..de01387 100644
--- a/src/lread.c
+++ b/src/lread.c
@@ -2693,7 +2693,11 @@ read1 (readcharfun, pch, first_in_list)
 	 old-style.  For Emacs-25, we should completely remove this
 	 first_in_list exception (old-style can still be obtained via
 	 "(\`" anyway).  */
-      if (first_in_list && (c = READCHAR, UNREAD (c), c == ' '))
+      {
+	 int next_char = READCHAR;
+	 UNREAD (next_char);
+
+      if (first_in_list && next_char == ' ')
 	{
 	  Vold_style_backquotes = Qt;
 	  goto default_label;
@@ -2708,6 +2712,7 @@ read1 (readcharfun, pch, first_in_list)
 
 	  return Fcons (Qbackquote, Fcons (value, Qnil));
 	}
+      }
 
     case ',':
       if (new_backquote_flag)

---
Makoto Fujiwara, 
Chiba, Japan, Narita Airport and Disneyland prefecture.