(read-regexp): Add regexp for symbol at point to the defaults (Bug#13687).

* lisp/replace.el (read-regexp): Tighten the regexp that matches tag.
When tag is retrieved with `find-tag-default', use regexp that
matches tag at point.  Also update docstring.

1 files changed, 14 insertions, 9 deletions

diff --git a/lisp/replace.el b/lisp/replace.el
index 7757426cf95..0b8aaa7d349 100644
--- a/lisp/replace.el
+++ b/lisp/replace.el
@@ -585,27 +585,32 @@ of `history-length', which see.")
 When PROMPT doesn't end with a colon and space, it adds a final \": \".
 If DEFAULTS is non-nil, it displays the first default in the prompt.
 
-Non-nil optional arg DEFAULTS is a string or a list of strings that
-are prepended to a list of standard default values, which include the
-string at point, the last isearch regexp, the last isearch string, and
-the last replacement regexp.
+Optional arg DEFAULTS is a string or a list of strings that are
+prepended to a list of standard default values, which include the
+tag at point, the last isearch regexp, the last isearch string,
+and the last replacement regexp.
 
 Non-nil HISTORY is a symbol to use for the history list.
 If HISTORY is nil, `regexp-history' is used."
-  (let* ((default (if (consp defaults) (car defaults) defaults))
-         (defaults
+  (let* ((defaults
            (append
             (if (listp defaults) defaults (list defaults))
-            (list (regexp-quote
-                   (or (funcall (or find-tag-default-function
+            (list
+             ;; Regexp for tag at point.
+             (let* ((tagf (or find-tag-default-function
                                     (get major-mode 'find-tag-default-function)
                                     'find-tag-default))
-                       ""))
+                    (tag (funcall tagf)))
+               (cond ((not tag) "")
+                     ((eq tagf 'find-tag-default)
+                      (format "\\_<%s\\_>" (regexp-quote tag)))
+                     (t (regexp-quote tag))))
                   (car regexp-search-ring)
                   (regexp-quote (or (car search-ring) ""))
                   (car (symbol-value
                         query-replace-from-history-variable)))))
          (defaults (delete-dups (delq nil (delete "" defaults))))
+         (default (car defaults))
          ;; Do not automatically add default to the history for empty input.
          (history-add-new-input nil)
          (input (read-from-minibuffer