[O] org-capture: Avoid inserting a new line when the template is empty

[xristos]

Hello,

An example of a capture workflow that I am using all the time
is the following:

("bbp" "Preview book" plain
 (file+function "~/org/books.org.gpg" xristos/org-capture-preview-find-location)
  "" :immediate-finish t :jump-to-captured t :empty-lines 0)

The idea is that the function I provide is fully responsible for cursor 
positioning
and entry manipulation. To that end, I pass an empty template ("") and
set :immediate-finish to t. This has been working fine with an older Org
version but since I recently updated to Org 9.1.13, org-capture-fill-template 
will
insert a new line every single time which is not what I want to happen.

The relevant code is at org-capture.el, line 1843. I think that having a way
to tell Org not to change the user-provided template at all and just use
it verbatim would be useful in the general sense.

For my own needs, I've added an extra property (:verbatim-template) which I
check for inside org-capture-fill-template:

@@ -1840,7 +1840,8 @@ The template may still contain \"%?\" for cursor 
positioning."
       (goto-char (point-max))
       (skip-chars-backward " \t\n")
       (delete-region (point) (point-max))
-      (insert "\n")
+      (unless (org-capture-get :verbatim-template)
+       (insert "\n"))
 
Chris