Subject: bug#17284: Host name completion in shell mode take 45 seconds

From: Stefan Monnier <[email-masked]>
Date: Fri, 03 Apr 2015 09:28:44 -0400

>> pcmpl-ssh-known-hosts: Use `char-before' instead of `looking-back'.
> Couldn't the byte-compiler warn when `looking-back' is used without
> specifying LIMIT?  Making LIMIT non-optional seems too harsh.

diff --git a/lisp/subr.el b/lisp/subr.el
index 163a1c4..16a3440 100644
--- a/lisp/subr.el
+++ b/lisp/subr.el
@@ -3485,6 +3484,7 @@ LIMIT.
 
 As a general recommendation, try to avoid using `looking-back'
 wherever possible, since it is slow."
+  (declare (advertised-calling-convention (regexp limit &optional greedy)))
   (let ((start (point))
 	(pos
 	 (save-excursion

-- Stefan