Don't request completions for zero-length input

Fixes a bug in which incorrect completion output was displayed, for
example when point was after a closing paren.

1 files changed, 3 insertions, 2 deletions

diff --git a/lisp/progmodes/python.el b/lisp/progmodes/python.el
index f75b5cb51ae..47bdef2c928 100644
--- a/lisp/progmodes/python.el
+++ b/lisp/progmodes/python.el
@@ -1633,8 +1633,9 @@ completions on the current context."
                      (string-match "^\\(from\\|import\\)[ \t]" line))
                 (python-shell-completion--get-completions
                  line process python-shell-module-completion-string-code)
-              (python-shell-completion--get-completions
-               input process python-shell-completion-string-code)))
+              (and (> (length input) 0)
+                   (python-shell-completion--get-completions
+                    input process python-shell-completion-string-code))))
            (completion (when completions
                          (try-completion input completions))))
       (cond ((eq completion t)