[O] Capture Bug?

[lists]

I have a capture template which prompts for a file name and uses this to 
create a filename with a datestamp:

(defun capture-pelican-draft-file (path)
  (let ((name (read-string "Name: ")))
    (expand-file-name (format "%s-%s.org"
                              (format-time-string "%Y-%m-%d")
                              name) path)))


("g"
   "New blog post (ianbarton.net)"
   plain
   (file (capture-pelican-draft-file  
"~/Documents/emacs/web_sites/ianbarton.net/org/_posts"))
   "#+AUTHOR: Ian Barton\n#+DATE: %u\n#+PROPERTY: MODIFIED: 
\n#+TITLE\n#+CATEGORY: Blog \n#+PROPERTY: TAGS \n#+PROPERTY: SUMMARY 
\n#+SETUPFILE: ../setup.org\n\n")


On the current git master the function capture-pelican-draft-file 
doesn't seem to be evaluated, resulting in a "File name doesn't exist" 
error. Doing git bisect seems to point at the commit below:

8860c92f62dac87267416708e81bc8aec026fcc7 is the first bad commit
commit 8860c92f62dac87267416708e81bc8aec026fcc7
Author: Nicolas Goaziou <address@hidden>
Date:   Fri Jun 24 00:55:03 2016 +0200

    ob-exp: Small fix

    * lisp/ob-exp.el (org-babel-exp-src-block): Use `symbol-name' 
instead of
      `eval' since the argument is a dynamically scoped variable anyhow.

Ian.