master 7f1dae1: Fix effect-free warning in ob-screen.el while loop

[Basil L. Contovounesios]

branch: master
commit 7f1dae114dffbf4bdec60e38ada4eb0673cfb4e2
Author: Basil L. Contovounesios <address@hidden>
Commit: Basil L. Contovounesios <address@hidden>

    Fix effect-free warning in ob-screen.el while loop
    
    The warning was introduced and detected by an optimizer addition
    proposed in the following thread:
    https://lists.gnu.org/archive/html/emacs-devel/2019-12/msg00711.html
    
    * lisp/org/ob-screen.el (org-babel-screen-test): Avoid 'value
    returned from (format "...") is unused' warning by doing something
    more useful than busy string manipulation while waiting for an
    asynchronous subprocess to make the temporary file readable.
---
 lisp/org/ob-screen.el | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lisp/org/ob-screen.el b/lisp/org/ob-screen.el
index ad00ee0..837c18f 100644
--- a/lisp/org/ob-screen.el
+++ b/lisp/org/ob-screen.el
@@ -126,7 +126,7 @@ The terminal should shortly flicker."
     ;; XXX: need to find a better way to do the following
     (while (not (file-readable-p tmpfile))
       ;; do something, otherwise this will be optimized away
-      (format "org-babel-screen: File not readable yet."))
+      (sit-for 0.1))
     (setq tmp-string (with-temp-buffer
                        (insert-file-contents-literally tmpfile)
                        (buffer-substring (point-min) (point-max))))