erc-backend.el: Give hook-name a default value of nil and add-to-list unconditionally. Fixes debbugs:19363

2 files changed, 10 insertions, 2 deletions

diff --git a/lisp/erc/ChangeLog b/lisp/erc/ChangeLog
index 8c8a3bfae5c..8e0c31a7dec 100644
--- a/lisp/erc/ChangeLog
+++ b/lisp/erc/ChangeLog
@@ -1,3 +1,8 @@
+2015-01-14  Dima Kogan  <dima@secretsauce.net>
+
+        * erc-backend.el (define-erc-response-handler): Give hook-name
+        default value of nil and add-to-list (bug#19363)
+
 2014-11-10  Kelvin White  <kwhite@gnu.org>
 
         * erc-stamp.el (erc-timestamp-intangible): Change version tag to 24.5.
diff --git a/lisp/erc/erc-backend.el b/lisp/erc/erc-backend.el
index b8c67860e20..8ce199fbcbb 100644
--- a/lisp/erc/erc-backend.el
+++ b/lisp/erc/erc-backend.el
@@ -1162,8 +1162,11 @@ add things to `%s' instead."
           (cl-loop for alias in aliases
                    collect (intern (format "erc-server-%s-functions" alias)))))
     `(prog2
-         ;; Normal hook variable.
-         (defvar ,hook-name ',fn-name ,(format hook-doc name))
+         ;; Normal hook variable.  The variable may already have a
+         ;; value at this point, so I default to nil, and (add-hook)
+         ;; unconditionally
+         (defvar ,hook-name nil ,(format hook-doc name))
+         (add-to-list ',hook-name ',fn-name)
          ;; Handler function
          (defun ,fn-name (proc parsed)
            ,fn-doc