(grep): `tag-default' can be nil.

diff --git a/lisp/progmodes/compile.el b/lisp/progmodes/compile.el
index 77bf8bf0ad02162b2cc1b028f5d5ccfab9a38500..cf46b2d661c720e7baeace5d3ad63b3466f4c4a2 100644 (file)
--- a/lisp/progmodes/compile.el
+++ b/lisp/progmodes/compile.el
@@ -609,20 +609,20 @@ if that history list is empty)."
      (unless grep-command
        (grep-compute-defaults))
      (when arg
-       (let* ((tag-default
-              (funcall (or find-tag-default-function
-                           (get major-mode 'find-tag-default-function)
-                           ;; We use grep-tag-default instead of
-                           ;; find-tag-default, to avoid loading etags.
-                           'grep-tag-default))))
+       (let ((tag-default
+             (funcall (or find-tag-default-function
+                          (get major-mode 'find-tag-default-function)
+                          ;; We use grep-tag-default instead of
+                          ;; find-tag-default, to avoid loading etags.
+                          'grep-tag-default))))
         (setq grep-default (or (car grep-history) grep-command))
         ;; Replace the thing matching for with that around cursor
         (when (string-match "[^ ]+\\s +\\(-[^ ]+\\s +\\)*\\(\"[^\"]+\"\\|[^ ]+\\)\\(\\s-+\\S-+\\)?" grep-default)
           (unless (or (match-beginning 3) (not (stringp buffer-file-name)))
             (setq grep-default (concat grep-default "*."
                                        (file-name-extension buffer-file-name))))
-          (setq grep-default (replace-match tag-default t t
-                                              grep-default 2)))))
+          (setq grep-default (replace-match (or tag-default "")
+                                            t t grep-default 2)))))
      (list (read-from-minibuffer "Run grep (like this): "
                                 (or grep-default grep-command)
                                 nil nil 'grep-history))))