Find-grep can only search on plain strings

* lisp/gnus/gnus-search.el (gnus-search-indexed-massage-output): Drop
  any list expression.

diff --git a/lisp/gnus/gnus-search.el b/lisp/gnus/gnus-search.el
index 877ff11c178504d97a8e2929a6654c7c304a18f8..fcbb23269782ec682f8cb376942a3441a0a5b045 100644 (file)
--- a/lisp/gnus/gnus-search.el
+++ b/lisp/gnus/gnus-search.el
@@ -1888,6 +1888,11 @@ Assume \"size\" key is equal to \"larger\"."
 
 ;;; Find-grep interface
 
+(cl-defmethod gnus-search-transform-expression ((_engine gnus-search-find-grep)
+                                               (_ list))
+  ;; Drop everything that isn't a plain string.
+  nil)
+
 (cl-defmethod gnus-search-run-search ((engine gnus-search-find-grep)
                                      server query
                                      &optional groups)