(read-regexp): Return empty string when `default-value' is nil.

(keep-lines-read-args): Don't use empty string as the
default value for `read-regexp'.  (Bug#2495)

diff --git a/lisp/replace.el b/lisp/replace.el
index a375c87e74f344286673afc2c939dba5290a5764..c69b4cd3c2b25336d4e4a0e699ac0220700fddd8 100644 (file)
--- a/lisp/replace.el
+++ b/lisp/replace.el
@@ -556,7 +556,7 @@ regexp, the last isearch string, and the last replacement regexp."
             (format "%s: " prompt))
           nil nil nil 'regexp-history defaults t)))
     (if (equal input "")
-       default-value
+       (or default-value input)
       (prog1 input
        (add-to-history 'regexp-history input)))))
 
@@ -570,7 +570,7 @@ regexp, the last isearch string, and the last replacement regexp."
   "Read arguments for `keep-lines' and friends.
 Prompt for a regexp with PROMPT.
 Value is a list, (REGEXP)."
-  (list (read-regexp prompt "") nil nil t))
+  (list (read-regexp prompt) nil nil t))
 
 (defun keep-lines (regexp &optional rstart rend interactive)
   "Delete all lines except those containing matches for REGEXP.