(tags-table-including): Take new third arg CORE-ONLY. If non-nil,

ignore files without extant buffers.
(visit-tags-table-buffer): Call tags-table-including first with
CORE-ONLY set, and then afterwards with it clear.

diff --git a/lisp/progmodes/etags.el b/lisp/progmodes/etags.el
index 098b82c137693fc920cab579340e113ed4e8b818..158885c1887de13d3cd28f37d2d6ea21f19df086 100644 (file)
--- a/lisp/progmodes/etags.el
+++ b/lisp/progmodes/etags.el
@@ -260,17 +260,20 @@ file the tag was in."
   list)
 
 ;; Subroutine of visit-tags-table-buffer.  Frobs its local vars.
-;; Search TABLES for one that has tags for THIS-FILE.  Recurses
-;; on included tables.  Returns the tail of TABLES (or of an
-;; inner included list) whose car is a table listing THIS-FILE.
-(defun tags-table-including (this-file tables &optional recursing)
+;; Search TABLES for one that has tags for THIS-FILE.  Recurses on
+;; included tables.  Returns the tail of TABLES (or of an inner
+;; included list) whose car is a table listing THIS-FILE.  If
+;; CORE-ONLY is non-nil, check only tags tables that are already in
+;; buffers--don't visit any new files.
+(defun tags-table-including (this-file tables core-only &optional recursing)
   (let ((found nil))
     ;; Loop over TABLES, looking for one containing tags for THIS-FILE.
     (while (and (not found)
                tables)
       (let ((tags-file-name (tags-expand-table-name (car tables))))
        (if (or (get-file-buffer tags-file-name)
-               (file-exists-p tags-file-name)) ;XXX check all in core first.
+               (and (not core-only)
+                    (file-exists-p tags-file-name)))
            (progn
              ;; Select the tags table buffer and get the file list up to date.
              (visit-tags-table-buffer 'same)
@@ -296,6 +299,7 @@ file the tag was in."
                                   ;; Recurse on the list of included tables.
                                   (tags-table-including this-file
                                                         tags-included-tables
+                                                        core-only
                                                         t))
                             (if found
                                 ;; One of them lists THIS-FILE.
@@ -371,8 +375,16 @@ Returns t if it visits a tags table, or nil if there are no more in the list."
                ;; tags for the current buffer's file.
                ;; If one is found, the lists will be frobnicated,
                ;; and CONT will be set non-nil so we don't do it below.
-               (car (save-excursion (tags-table-including buffer-file-name
-                                                          tags-table-list)))
+               (car (or 
+                     ;; First check only tables already in buffers.
+                     (save-excursion (tags-table-including buffer-file-name
+                                                              tags-table-list
+                                                              t))
+                     ;; Since that didn't find any, now do the
+                     ;; expensive version: reading new files.
+                     (save-excursion (tags-table-including buffer-file-name
+                                                           tags-table-list
+                                                           nil))))
                ;; Fourth, use the user variable tags-file-name, if it is not
                ;; already in tags-table-list.
                (and tags-file-name