Exclude NL and TAB from c0-control group for glyphless display.

 international/characters.el (glyphless-char-display-control):
 Exclude newline and TAB from the c0-control group.

2 files changed, 12 insertions, 2 deletions

diff --git a/lisp/ChangeLog b/lisp/ChangeLog
index 1612fbe9ab9..f26911298e3 100644
--- a/lisp/ChangeLog
+++ b/lisp/ChangeLog
@@ -1,3 +1,8 @@
+2010-11-27  Eli Zaretskii  <eliz@gnu.org>
+
+        * international/characters.el (glyphless-char-display-control):
+        Exclude newline and TAB from the c0-control group.
+
 2010-11-27  Glenn Morris  <rgm@gnu.org>
 
         * mail/sendmail.el (build-mail-aliases): Doc fix for autoload.
diff --git a/lisp/international/characters.el b/lisp/international/characters.el
index 73185d78f2b..db5fe7e86ba 100644
--- a/lisp/international/characters.el
+++ b/lisp/international/characters.el
@@ -1305,7 +1305,12 @@ This function updates the char-table `glyphless-char-display'."
           (error "Invalid glyphless character display method: %s" method))
       (cond ((eq target 'c0-control)
              (set-char-table-range glyphless-char-display '(#x00 . #x1F)
-                                   method))
+                                   method)
+             ;; Users will not expect their newlines and TABs be
+             ;; displayed as anything but themselves, so exempt those
+             ;; two characters from c0-control.
+             (set-char-table-range glyphless-char-display #x9 nil)
+             (set-char-table-range glyphless-char-display #xa nil))
             ((eq target 'c1-control)
              (set-char-table-range glyphless-char-display '(#x80 . #x9F)
                                    method))
@@ -1344,7 +1349,7 @@ specifying the method of displaying characters belonging to that
 group.
 
 GROUP must be one of these symbols:
-  `c0-control':     U+0000..U+001F.
+  `c0-control':     U+0000..U+001F, but excluding newline and TAB.
   `c1-control':     U+0080..U+009F.
   `format-control': Characters of Unicode General Category `Cf',
                     such as U+200C (ZWNJ), U+200E (LRM), but