Don't print the "decomposition" line for control chars in what-cursor-position

This is a temporary workaround for bug #23594, where the decomposition line
for linefeed corrupted the display on a Linux virtual terminal.

* lisp/descr-text.el (describe-char): Remove `decomposition' from the list of
character code properties printed for control characters.

1 files changed, 10 insertions, 3 deletions

diff --git a/lisp/descr-text.el b/lisp/descr-text.el
index 5f1a4304342..528820876ec 100644
--- a/lisp/descr-text.el
+++ b/lisp/descr-text.el
@@ -806,9 +806,16 @@ relevant to POS."
                         'describe-char-unidata-list))
              'follow-link t)
             (insert "\n")
-            (dolist (elt (if (eq describe-char-unidata-list t)
-                             (nreverse (mapcar 'car char-code-property-alist))
-                           describe-char-unidata-list))
+            (dolist (elt
+                     (cond ((eq describe-char-unidata-list t)
+                            (nreverse (mapcar 'car char-code-property-alist)))
+                           ((< char 32)
+                            ;; Temporary fix (2016-05-22): The
+                            ;; decomposition item for \n corrupts the
+                            ;; display on a Linux virtual terminal.
+                            ;; (Bug #23594).
+                            (remq 'decomposition describe-char-unidata-list))
+                           (t describe-char-unidata-list)))
               (let ((val (get-char-code-property char elt))
                     description)
                 (when val