[elpa] externals/transient 626d105ecf 274/366: transient--read-number-N: Return empty string instead of nil

[Jonas Bernoulli]

branch: externals/transient
commit 626d105ecfb44ab9e1a4bf1fccb9340d6488b631
Author: Jonas Bernoulli <jonas@bernoul.li>
Commit: Jonas Bernoulli <jonas@bernoul.li>

    transient--read-number-N: Return empty string instead of nil
    
    This affects `transient-read-number-N+' and `transient-read-number-N',
    which are only intended for use as `:reader' of infix commands and are
    called by `transient-infix-read' which understand how to treat nil and
    the empty string depending on the values of other slots.
    
    For empty input return the empty string instead of nil, informing
    `transient-infix-read' that what is being returned is the empty value
    of the argument and not the instruction to altogether turn off the
    argument.  This makes it trivial to support options that can be off,
    on, or have a numeric value:
    
     (transient-define-argument magit-diff:-C ()
       :description "Detect copies"
       :class 'transient-option
       :argument "-C"
    +  :allow-empty t
       :reader 'transient-read-number-N+)
---
 lisp/transient.el | 13 ++++++-------
 1 file changed, 6 insertions(+), 7 deletions(-)

diff --git a/lisp/transient.el b/lisp/transient.el
index 4984977d04..a9e026e77e 100644
--- a/lisp/transient.el
+++ b/lisp/transient.el
@@ -2606,13 +2606,12 @@ stand-alone command."
     (cl-block nil
       (while t
         (let ((str (read-from-minibuffer prompt initial-input nil nil 
history)))
-          (cond ((string-equal str "")
-                 (cl-return nil))
-                ((string-match-p (if include-zero
-                                     "\\`\\(0\\|[1-9][0-9]*\\)\\'"
-                                   "\\`[1-9][0-9]*\\'")
-                                 str)
-                 (cl-return str))))
+          (when (or (string-equal str "")
+                    (string-match-p (if include-zero
+                                        "\\`\\(0\\|[1-9][0-9]*\\)\\'"
+                                      "\\`[1-9][0-9]*\\'")
+                                    str))
+            (cl-return str)))
         (message "Please enter a natural number (%s zero)."
                  (if include-zero "including" "excluding"))
         (sit-for 1)))))