Make goto-char offer the number at point as default

* lisp/subr.el (read-natnum-interactive): New function to read natural
numbers for interactive functions.
* src/editfns.c (Fgoto_char): Call read-natnum-interactive from the
interactive definition of goto-char to offer the number at point as
default.  Also expand the docstring to document this new interactive
behavior.
* doc/emacs/basic.texi (Moving Point): Expand the Emacs manual to
document this new behavior.
* etc/NEWS: And announce it (bug#45199).

1 files changed, 7 insertions, 2 deletions

diff --git a/src/editfns.c b/src/editfns.c
index 4104edd77fd..e4c4141ef5e 100644
--- a/src/editfns.c
+++ b/src/editfns.c
@@ -188,11 +188,16 @@ DEFUN ("point-marker", Fpoint_marker, Spoint_marker, 0, 0, 0,
   return build_marker (current_buffer, PT, PT_BYTE);
 }
 
-DEFUN ("goto-char", Fgoto_char, Sgoto_char, 1, 1, "NGoto char: ",
+DEFUN ("goto-char", Fgoto_char, Sgoto_char, 1, 1,
+         "(goto-char--read-natnum-interactive \"Go to char: \")",
        doc: /* Set point to POSITION, a number or marker.
 Beginning of buffer is position (point-min), end is (point-max).
 
-The return value is POSITION.  */)
+The return value is POSITION.
+
+If called interactively, a numeric prefix argument specifies
+POSITION; without a numeric prefix argument, read POSITION from the
+minibuffer.  The default value is the number at point (if any).  */)
   (register Lisp_Object position)
 {
   if (MARKERP (position))