Use a square root character in calc displays

* lisp/calc/calccomp.el (math-compose-sqrt): Use a square root
character, if possible (bug#22919).  Suggested by Zephyr Pellerin
<zephyr.pellerin@gmail.com>.

diff --git a/lisp/calc/calccomp.el b/lisp/calc/calccomp.el
index 0367c537b5a87befab99d00488607d88a67beecf..1f3ae842638380d99e17350833a1ce8cee0b0edb 100644 (file)
--- a/lisp/calc/calccomp.el
+++ b/lisp/calc/calccomp.el
@@ -1018,7 +1018,8 @@
                    (make-string (+ w 2) ?\_))
            (list 'horiz
                  (if (= h 1)
-                     "V"
+                     (if (char-displayable-p ?√)
+                          "√" "V")
                    (append (list 'vleft (1- a))
                            (make-list (1- h) " |")
                            '("\\|")))