bug#26552: [patch] nlinum margin width calculation (emacs <25)

[Christophe Rhodes]

Hi,

I think the calculation that nlinum-mode does to guess the margin size
in the absence of font width information (in emacs versions less than
25) uses the wrong bit of font information: the pixel size, rather than
the font height.  Trivial patch below, which fixes the problem for me.

Best wishes,

Christophe

--- nlinum.el~  2017-04-17 20:41:35.595122970 +0100
+++ nlinum.el   2017-04-17 21:46:37.713053714 +0100
@@ -71,7 +71,7 @@
   (nlinum--setup-windows))
 
 (defun nlinum--face-height (face)
-  (aref (font-info (face-font face)) 2))
+  (aref (font-info (face-font face)) 3))
 
 (defun nlinum--face-width (face)        ;New info only in Emacs>=25.
   (let ((fi (font-info (face-font face))))