* minibuffer.el (tags-completion-at-point-function): New function.

(completion-at-point-functions): Use it.

* cedet/semantic.el (semantic-completion-at-point-function): New function.
(semantic-mode): Use semantic-completion-at-point-function for
completion-at-point-functions instead.

* progmodes/etags.el (complete-tag): Revert last change.

4 files changed, 53 insertions, 18 deletions

diff --git a/lisp/ChangeLog b/lisp/ChangeLog
index d752fd3fb69..e04ebf63812 100644
--- a/lisp/ChangeLog
+++ b/lisp/ChangeLog
@@ -1,3 +1,14 @@
+2010-04-29  Chong Yidong  <cyd@stupidchicken.com>
+
+        * minibuffer.el (tags-completion-at-point-function): New function.
+        (completion-at-point-functions): Use it.
+
+        * cedet/semantic.el (semantic-completion-at-point-function): New function.
+        (semantic-mode): Use semantic-completion-at-point-function for
+        completion-at-point-functions instead.
+
+        * progmodes/etags.el (complete-tag): Revert last change.
+
 2010-04-29  Alan Mackenzie  <acm@muc.de>
 
         * progmodes/cc-mode.el (c-extend-region-for-CPP): Fix an
diff --git a/lisp/cedet/semantic.el b/lisp/cedet/semantic.el
index 8df4feaa2bb..99e594a4638 100644
--- a/lisp/cedet/semantic.el
+++ b/lisp/cedet/semantic.el
@@ -1083,7 +1083,8 @@ Semantic mode.
         ;; Add semantic-ia-complete-symbol to
         ;; completion-at-point-functions, so that it is run from
         ;; M-TAB.
-        (add-hook 'completion-at-point-functions 'semantic-ia-complete-symbol)
+        (add-hook 'completion-at-point-functions
+                  'semantic-completion-at-point-function)
         (if global-ede-mode
             (define-key cedet-menu-map [cedet-menu-separator] '("--")))
         (dolist (b (buffer-list))
@@ -1091,7 +1092,8 @@ Semantic mode.
             (semantic-new-buffer-fcn))))
     ;; Disable all Semantic features.
     (remove-hook 'mode-local-init-hook 'semantic-new-buffer-fcn)
-    (remove-hook 'completion-at-point-functions 'semantic-ia-complete-symbol)
+    (remove-hook 'completion-at-point-functions
+                 'semantic-completion-at-point-function)
     (define-key cedet-menu-map [cedet-menu-separator] nil)
     (define-key cedet-menu-map [semantic-options-separator] nil)
     ;; FIXME: handle semanticdb-load-ebrowse-caches
@@ -1099,6 +1101,9 @@ Semantic mode.
       (if (and (boundp mode) (eval mode))
           (funcall mode -1)))))
 
+(defun semantic-completion-at-point-function ()
+  'semantic-ia-complete-symbol)
+
 ;;; Autoload some functions that are not in semantic/loaddefs
 
 (autoload 'global-semantic-idle-completions-mode "semantic/idle"
diff --git a/lisp/minibuffer.el b/lisp/minibuffer.el
index b44742c0bdc..80e5f0ad10f 100644
--- a/lisp/minibuffer.el
+++ b/lisp/minibuffer.el
@@ -1157,7 +1157,7 @@ Point needs to be somewhere between START and END."
           (call-interactively 'minibuffer-complete)
         (delete-overlay ol)))))
 
-(defvar completion-at-point-functions '(complete-tag)
+(defvar completion-at-point-functions '(tags-completion-at-point-function)
   "Special hook to find the completion table for the thing at point.
 It is called without any argument and should return either nil,
 or a function of no argument to perform completion (discouraged),
@@ -1169,14 +1169,9 @@ Currently supported properties are:
  `:predicate'           a predicate that completion candidates need to satisfy.
  `:annotation-function' the value to use for `completion-annotate-function'.")
 
-(declare-function tags-lazy-completion-table "etags.el" ())
-
-(defun complete-tag ()
-  "Perform tags completion on the text around point.
-If no tags table is loaded, do nothing and return nil.
-Otherwise, complete to the set of names listed in the tags table.
-The string to complete is chosen in the same way as the default
-for `find-tag'."
+(defun tags-completion-at-point-function ()
+  "Using tags, return a completion table for the text around point.
+If no tags table is loaded, do nothing and return nil."
   (interactive)
   (when (or tags-table-list tags-file-name)
     (require 'etags)
@@ -1185,14 +1180,11 @@ for `find-tag'."
                                     case-fold-search))
           (pattern (funcall (or find-tag-default-function
                                 (get major-mode 'find-tag-default-function)
-                                'find-tag-default)))
-          (comp-table (tags-lazy-completion-table))
-          beg)
+                                'find-tag-default))))
       (when pattern
-        (search-backward pattern)
-        (setq beg (point))
-        (forward-char (length pattern))
-        (completion-in-region beg (point) comp-table)))))
+        (tags-lazy-completion-table)))))
+
+(declare-function tags-lazy-completion-table "etags.el" ())
 
 (defun complete-symbol (&optional arg)
   "Perform completion on the text around point.
diff --git a/lisp/progmodes/etags.el b/lisp/progmodes/etags.el
index bde75179be8..23e175cbe7d 100644
--- a/lisp/progmodes/etags.el
+++ b/lisp/progmodes/etags.el
@@ -2027,6 +2027,33 @@ see the doc of that variable if you want to add names to the list."
   (interactive)
   (quit-window t (selected-window)))
 
+;;;###autoload
+(defun complete-tag ()
+  "Perform tags completion on the text around point.
+Completes to the set of names listed in the current tags table.
+The string to complete is chosen in the same way as the default
+for \\[find-tag] (which see)."
+  (interactive)
+  (or tags-table-list
+      tags-file-name
+      (error "%s"
+             (substitute-command-keys
+              "No tags table loaded; try \\[visit-tags-table]")))
+  (let ((completion-ignore-case (if (memq tags-case-fold-search '(t nil))
+                                    tags-case-fold-search
+                                  case-fold-search))
+        (pattern (funcall (or find-tag-default-function
+                              (get major-mode 'find-tag-default-function)
+                              'find-tag-default)))
+        (comp-table (tags-lazy-completion-table))
+        beg)
+    (or pattern
+        (error "Nothing to complete"))
+    (search-backward pattern)
+    (setq beg (point))
+    (forward-char (length pattern))
+    (completion-in-region beg (point) comp-table)))
+
 (dolist (x '("^No tags table in use; use .* to select one$"
              "^There is no default tag$"
              "^No previous tag locations$"