(vmotion): handle the case where `minibuf_prompt' is nil.

diff --git a/src/indent.c b/src/indent.c
index 9c29d459870cd5bb3dc9f6e8cd29d55f08bf7088..e075e236d1b21353680d6febe49f6f56ab02a027 100644 (file)
--- a/src/indent.c
+++ b/src/indent.c
@@ -1095,7 +1095,7 @@ vmotion (from, vtarget, w)
      position even if the minibuffer window has scrolled.  */
   if (EQ (window, minibuf_window))
     {
-      if (minibuf_prompt_width == 0)
+      if (minibuf_prompt_width == 0 && STRINGP (minibuf_prompt))
        minibuf_prompt_width
          = string_display_width (minibuf_prompt, Qnil, Qnil);