* lisp/replace.el (how-many): Fix rstart and !rend case.

Fixes: debbugs:15589

1 files changed, 6 insertions, 3 deletions

diff --git a/lisp/replace.el b/lisp/replace.el
index abb59a674e3..d92fb6809ef 100644
--- a/lisp/replace.el
+++ b/lisp/replace.el
@@ -810,9 +810,12 @@ a previously found match."
    (keep-lines-read-args "How many matches for regexp"))
   (save-excursion
     (if rstart
-        (progn
-          (goto-char (min rstart rend))
-          (setq rend (max rstart rend)))
+        (if rend
+            (progn
+              (goto-char (min rstart rend))
+              (setq rend (max rstart rend)))
+          (goto-char rstart)
+          (setq rend (point-max)))
       (if (and interactive transient-mark-mode mark-active)
           (setq rstart (region-beginning)
                 rend (region-end))