Advise ivy-read-action for MELPA Stable and ELPA users

For MELPA Stable and ELPA users, until the next version of ivy is
released, we need to advise `ivy-read-action' to implement
multi-character action keys. The advice only operates on
counsel-projectile commands (identified by the fact that
`ivy-state-caller' starts with \"counsel-projectile\"), so as not to
mess up with the general ivy setup.

counsel-projectile.el

@@ -44,7 +44,61 @@
 
 (require 'counsel)
 (require 'projectile)
-                      
+
+;;;; compatibility
+
+;; For MELPA Stable and ELPA users, until the next version of ivy is
+;; released, we need to advise `ivy-read-action' to implement
+;; multi-character action keys. The advice only operates on
+;; counsel-projectile commands (identified by the fact that
+;; `ivy-state-caller' starts with \"counsel-projectile\"), so as not
+;; to mess up with the general ivy setup.
+
+(defun counsel-projectile--read-action ()
+  ;; This is a copy of `ivy-read-action' as of commit 7042d70
+  ;; implementing multi-character action keys.
+  (let ((actions (ivy-state-action ivy-last)))
+    (if (null (ivy--actionp actions))
+	t
+      (let* ((hint (funcall ivy-read-action-format-function (cdr actions)))
+	     (resize-mini-windows t)
+	     (key "")
+	     action-idx)
+	(while (and (setq action-idx (cl-position-if
+				      (lambda (x)
+					(string-prefix-p key (car x)))
+				      (cdr actions)))
+		    (not (string= key (car (nth (1+ action-idx) actions)))))
+	  (setq key (concat key (string (read-key hint)))))
+	(cond ((member key '("" ""))
+	       nil)
+	      ((null action-idx)
+	       (message "%s is not bound" key)
+	       nil)
+	      (t
+	       (message "")
+	       (setcar actions (1+ action-idx))
+	       (ivy-set-action actions)))))))
+
+(defun counsel-projectile--ivy-read-action-advice (oldfun)
+  ;; This is the advice function for `advice-add', falling back to the
+  ;; original function for non-counsel-projectile commands.
+  (if (string-prefix-p "counsel-projectile"
+		       (symbol-name (ivy-state-caller ivy-last)))
+      (counsel-projectile--read-action)
+    (funcall oldfun)))
+
+;; `advice-add' was introduced in Emacs 24.4, so we need to use
+;; `defadvice' instead for Emacs 24.3.
+(if (fboundp 'advice-add)
+    (advice-add #'ivy-read-action :around #'counsel-projectile--ivy-read-action-advice)
+  (defadvice ivy-read-action (around counsel-projectile-advice activate)
+    (setq ad-return-value
+	  (if (string-prefix-p "counsel-projectile"
+			       (symbol-name (ivy-state-caller ivy-last)))
+	      (counsel-projectile--read-action)
+	    ad-do-it))))
+
 ;;;; global
 
 (defgroup counsel-projectile nil