Don't pass invalid starting point to 'git checkout'

If the caller doesn't enter a base, an empty string is passed as the
starting point to 'git checkout', causing it to fail.  Instead, map
the empty string to nil, resulting in HEAD being used as the starting
point.

1 files changed, 2 insertions, 1 deletions

diff --git a/piem.el b/piem.el
index 800fb2c..b7b763f 100644
--- a/piem.el
+++ b/piem.el
@@ -353,7 +353,8 @@ in `piem-default-branch-function'."
              (append (if (string-empty-p new-branch)
                          (list "--detach")
                        (list "-b" new-branch))
-                     (list base))))
+                     (and (not (string-blank-p base))
+                          (list base)))))
     (piem-process-call nil piem-git-executable "am" "--scissors" mbox)
     (if (and piem-use-magit
              (fboundp 'magit-status-setup-buffer))