Clarify icomplete-show-matches-on-no-input doc string

* lisp/icomplete.el (icomplete-show-matches-on-no-input): Clarify
the meaning of the variable (bug#19031).

diff --git a/lisp/icomplete.el b/lisp/icomplete.el
index 4e546807b7f0c8cf77449ebecef73c09beb3e70b..9c1470812abc3e21e4a9803f449d356571d47734 100644 (file)
--- a/lisp/icomplete.el
+++ b/lisp/icomplete.el
@@ -75,7 +75,12 @@ everything preceding the ~/ is discarded so the interactive
 selection process starts again from the user's $HOME.")
 
 (defcustom icomplete-show-matches-on-no-input nil
-  "When non-nil, show completions when first prompting for input.
+  "If nil, don't wait for completions before showing the prompt.
+Instead, when there's no input, completions may be displayed
+asynchronously later, when the completions have been computed.
+
+If non-nil, always compute the completions first.
+
 This also means that if you traverse the list of completions with
 commands like `C-.' and just hit RET without typing any
 characters, the match under point will be chosen instead of the