(list-load-path-shadows): Exclude, from the path we search, all but

the first set of directories that include the standard Emacs Lisp files.

1 files changed, 47 insertions, 25 deletions

diff --git a/lisp/emacs-lisp/shadow.el b/lisp/emacs-lisp/shadow.el
index 7e49c8b6f17..cca8b350731 100644
--- a/lisp/emacs-lisp/shadow.el
+++ b/lisp/emacs-lisp/shadow.el
@@ -173,34 +173,56 @@ buffer called `*Shadows*'.  Shadowings are located by calling the
 \(non-interactive\) companion function, `find-emacs-lisp-shadows'."
   
   (interactive)
-  (let* ((shadows (find-emacs-lisp-shadows))
-         (n (/ (length shadows) 2))
-         (msg (format "%s Emacs Lisp load-path shadowing%s found"
-                      (if (zerop n) "No" (concat "\n" (number-to-string n)))
-                      (if (= n 1) " was" "s were"))))
-    (if (interactive-p)
-        (save-excursion
-          ;; We are interactive.
-          ;; Create the *Shadows* buffer and display shadowings there.
-          (let ((output-buffer (get-buffer-create "*Shadows*")))
-            (display-buffer output-buffer)
-            (set-buffer output-buffer)
-            (erase-buffer)
-            (while shadows
-              (insert (format "%s hides %s\n" (car shadows)
-                              (car (cdr shadows))))
-              (setq shadows (cdr (cdr shadows))))
-            (insert msg "\n")))
-      ;; We are non-interactive, print shadows via message.
-      (when shadows
-        (message "This site has duplicate Lisp libraries with the same name.
+  (let* ((path (copy-sequence load-path))
+        (tem path)
+        toplevs)
+    ;; If we can find simple.el in two places,
+    (while tem
+      (if (file-exists-p (expand-file-name "simple.el" (car tem)))
+          (setq toplevs (cons (car tem) toplevs)))
+      (setq tem (cdr tem)))
+    (if (> (length toplevs) 1)
+        ;; Cut off our copy of load-path right before
+        ;; the second directory which has simple.el in it.
+        ;; This avoids loads of duplications between the source dir
+        ;; and the dir where these files were copied by installation.
+        (let ((break (nth (- (length toplevs) 2) toplevs)))
+          (setq tem path)
+          (while tem
+            (if (eq (nth 1 tem) break)
+                (progn
+                  (setcdr tem nil)
+                  (setq tem nil)))
+            (setq tem (cdr tem)))))
+
+    (let* ((shadows (find-emacs-lisp-shadows path))
+           (n (/ (length shadows) 2))
+           (msg (format "%s Emacs Lisp load-path shadowing%s found"
+                        (if (zerop n) "No" (concat "\n" (number-to-string n)))
+                        (if (= n 1) " was" "s were"))))
+      (if (interactive-p)
+          (save-excursion
+            ;; We are interactive.
+            ;; Create the *Shadows* buffer and display shadowings there.
+            (let ((output-buffer (get-buffer-create "*Shadows*")))
+              (display-buffer output-buffer)
+              (set-buffer output-buffer)
+              (erase-buffer)
+              (while shadows
+                (insert (format "%s hides %s\n" (car shadows)
+                                (car (cdr shadows))))
+                (setq shadows (cdr (cdr shadows))))
+              (insert msg "\n")))
+        ;; We are non-interactive, print shadows via message.
+        (when shadows
+          (message "This site has duplicate Lisp libraries with the same name.
 If a locally-installed Lisp library overrides a library in the Emacs release,
 that can cause trouble, and you should probably remove the locally-installed
 version unless you know what you are doing.\n"))
-      (while shadows
-        (message "%s hides %s" (car shadows) (car (cdr shadows)))
-        (setq shadows (cdr (cdr shadows))))
-      (message "%s" msg))))
+        (while shadows
+          (message "%s hides %s" (car shadows) (car (cdr shadows)))
+          (setq shadows (cdr (cdr shadows))))
+        (message "%s" msg)))))
 
 (provide 'shadow)