(tags-verify-table): Be careful to use and update

tags-file-name and tags-table-list from the right buffer.
(tags-table-check-computed-list, tags-table-extend-computed-list)
(find-tag-noselect): Use with-current-buffer.

2 files changed, 40 insertions, 46 deletions

diff --git a/lisp/ChangeLog b/lisp/ChangeLog
index 37d24c0e1fd..2f889f6ac53 100644
--- a/lisp/ChangeLog
+++ b/lisp/ChangeLog
@@ -1,5 +1,10 @@
 2008-06-05  Stefan Monnier  <monnier@iro.umontreal.ca>
 
+        * progmodes/etags.el (tags-verify-table): Be careful to use and update
+        tags-file-name and tags-table-list from the right buffer.
+        (tags-table-check-computed-list, tags-table-extend-computed-list)
+        (find-tag-noselect): Use with-current-buffer.
+
         * emacs-lisp/trace.el (trace-entry-message, trace-exit-message):
         Use print-circle.
 
diff --git a/lisp/progmodes/etags.el b/lisp/progmodes/etags.el
index 7249e342e41..7aea6158f26 100644
--- a/lisp/progmodes/etags.el
+++ b/lisp/progmodes/etags.el
@@ -301,8 +301,7 @@ file the tag was in."
                      current-prefix-arg))
   (or (stringp file) (signal 'wrong-type-argument (list 'stringp file)))
   ;; Bind tags-file-name so we can control below whether the local or
-  ;; global value gets set.  Calling visit-tags-table-buffer will
-  ;; initialize a buffer for the file and set tags-file-name to the
+  ;; global value gets set.
   ;; Calling visit-tags-table-buffer with tags-file-name set to FILE will
   ;; initialize a buffer for FILE and set tags-file-name to the
   ;; fully-expanded name.
@@ -338,8 +337,7 @@ file the tag was in."
                      ;; it is initialized as a tag table buffer.
                      (save-excursion
                        (tags-verify-table (buffer-file-name table-buffer))))
-                (save-excursion
-                  (set-buffer table-buffer)
+                (with-current-buffer table-buffer
                   (if (tags-included-tables)
                       ;; Insert the included tables into the list we
                       ;; are processing.
@@ -378,8 +376,7 @@ such table and puts its included tables into the list."
               (setq computed (cons (car tables) computed)
                     table-buffer (get-file-buffer (car tables)))
               (if table-buffer
-                  (save-excursion
-                    (set-buffer table-buffer)
+                  (with-current-buffer table-buffer
                     (if (tags-included-tables)
                         ;; Insert the included tables into the list we
                         ;; are processing.
@@ -448,18 +445,19 @@ Returns non-nil if it is a valid table."
                  (funcall verify-tags-table-function))
           (revert-buffer t t)
           (tags-table-mode)))
-    (and (file-exists-p file)
-         (progn
-           (set-buffer (find-file-noselect file))
-           (or (string= file buffer-file-name)
-               ;; find-file-noselect has changed the file name.
-               ;; Propagate the change to tags-file-name and tags-table-list.
-               (let ((tail (member file tags-table-list)))
-                 (if tail
-                     (setcar tail buffer-file-name))
-                 (if (eq file tags-file-name)
-                     (setq tags-file-name buffer-file-name))))
-           (tags-table-mode)))))
+    (when (file-exists-p file)
+      (let* ((buf (find-file-noselect file))
+             (newfile (buffer-file-name buf)))
+        (unless (string= file newfile)
+          ;; find-file-noselect has changed the file name.
+          ;; Propagate the change to tags-file-name and tags-table-list.
+          (let ((tail (member file tags-table-list)))
+            (if tail (setcar tail newfile)))
+          (if (eq file tags-file-name) (setq tags-file-name newfile)))
+        ;; Only change buffer now that we're done using potentially
+        ;; buffer-local variables.
+        (set-buffer buf)
+        (tags-table-mode)))))
 
 ;; Subroutine of visit-tags-table-buffer.  Search the current tags tables
 ;; for one that has tags for THIS-FILE (or that includes a table that
@@ -883,22 +881,21 @@ See documentation of variable `tags-file-name'."
         (setq last-tag tagname))
       ;; Record the location so we can pop back to it later.
       (let ((marker (make-marker)))
-        (save-excursion
-          (set-buffer
-           ;; find-tag-in-order does the real work.
-           (find-tag-in-order
-            (if (and next-p last-tag) last-tag tagname)
-            (if regexp-p
-                find-tag-regexp-search-function
-              find-tag-search-function)
-            (if regexp-p
-                find-tag-regexp-tag-order
-              find-tag-tag-order)
-            (if regexp-p
-                find-tag-regexp-next-line-after-failure-p
-              find-tag-next-line-after-failure-p)
-            (if regexp-p "matching" "containing")
-            (or (not next-p) (not last-tag))))
+        (with-current-buffer
+            ;; find-tag-in-order does the real work.
+            (find-tag-in-order
+             (if (and next-p last-tag) last-tag tagname)
+             (if regexp-p
+                 find-tag-regexp-search-function
+               find-tag-search-function)
+             (if regexp-p
+                 find-tag-regexp-tag-order
+               find-tag-tag-order)
+             (if regexp-p
+                 find-tag-regexp-next-line-after-failure-p
+               find-tag-next-line-after-failure-p)
+             (if regexp-p "matching" "containing")
+             (or (not next-p) (not last-tag)))
           (set-marker marker (point))
           (run-hooks 'local-find-tag-hook)
           (ring-insert tags-location-ring marker)
@@ -1560,18 +1557,10 @@ that do nothing."
 
 ;; This might be a neat idea, but it's too hairy at the moment.
 ;;(defmacro tags-with-syntax (&rest body)
-;;   `(let ((current (current-buffer))
-;;         (otable (syntax-table))
-;;         (buffer (find-file-noselect (file-of-tag)))
-;;         table)
-;;       (unwind-protect
-;;         (progn
-;;           (set-buffer buffer)
-;;           (setq table (syntax-table))
-;;           (set-buffer current)
-;;           (set-syntax-table table)
-;;            ,@body)
-;;       (set-syntax-table otable))))
+;;   `(with-syntax-table
+;;        (with-current-buffer (find-file-noselect (file-of-tag))
+;;          (syntax-table))
+;;      ,@body))
 ;;(put 'tags-with-syntax 'edebug-form-spec '(&rest form))
 
 ;; exact file name match, i.e. searched tag must match complete file