(tags-loop-scan): Set default value to an error form.

diff --git a/lisp/progmodes/etags.el b/lisp/progmodes/etags.el
index 5c058d865e66008e218d6c0953543c1ac0446b19..0598e00fcc5c52b0c13e2fd38c624cdf75657963 100644 (file)
--- a/lisp/progmodes/etags.el
+++ b/lisp/progmodes/etags.el
@@ -1060,7 +1060,9 @@ if the file was newly read in, the value is the filename."
 (defvar tags-loop-operate nil
   "Form for `tags-loop-continue' to eval to change one file.")
 
-(defvar tags-loop-scan nil
+(defvar tags-loop-scan
+  '(error (substitute-command-keys
+          "No \\[tags-search] or \\[tags-query-replace] in progress."))
   "Form for `tags-loop-continue' to eval to scan one file.
 If it returns non-nil, this file needs processing by evalling
 \`tags-loop-operate'.  Otherwise, move on to the next file.")