Problem (bug?) with capture

[Thomas Holst <thomas.holst@de.bosch.com>]

Hello,

recently I encountered a problem with capture. I have a template in
which =:table-line= is set to a variable not a string. This used to work
but now throws an error.

Here is an ECM:

* Table
| col1  | col2 | col3 |
|-------+------+------|
| entry |      |      |
|-------+------+------|

* Template and elisp code

#+BEGIN_SRC elisp
  (setq th:line "II-1")

  (setq org-capture-templates
        '(("t" "Testing variable" table-line
        (file+headline "~/git/scratch/org-table-test.org" "Table")
        "| %?| |  |" :table-line-pos th:line :immediate-finish t)))
#+END_SRC

Calling this template throws an error:

: condition-case: Capture template ‘t’: stringp

When I set :table-line-pos to "II-1" everything works as expected. I
have a more complex template where an elisp function sets a variable for
the :table-line-pos. This worked up to some point in time but now stopped
working.

This is on:

(emacs-version)
"GNU Emacs 26.1 (build 1, x86_64-pc-linux-gnu, GTK+ Version 3.22.30) of
2018-07-02"


(org-version)
Org mode version 9.1.13 (release_9.1.13-900-g638f32 @
/home/thommy/git-emacs/org-mode/lisp/)

Thank you for looking into this.

-- 
Thomas