* lisp/files.el (dir-locals-collect-variables): Don't let errors stop us.

Use string-prefix-p.
(file-name-version-regexp): New var.
(file-name-sans-versions):
* lisp/jka-cmpr-hook.el (jka-compr-build-file-regexp): Use it,
(jka-compr-get-compression-info): Use dolist.
(jka-compr-compression-info-list): Don't bother specifying
version/backup regexps.

lisp/ChangeLog

@@ -1,3 +1,14 @@
+2010-12-08  Stefan Monnier  <monnier@iro.umontreal.ca>
+
+	* files.el (dir-locals-collect-variables): Don't let errors stop us.
+	Use string-prefix-p.
+	(file-name-version-regexp): New var.
+	(file-name-sans-versions):
+	* jka-cmpr-hook.el (jka-compr-build-file-regexp): Use it,
+	(jka-compr-get-compression-info): Use dolist.
+	(jka-compr-compression-info-list): Don't bother specifying
+	version/backup regexps.
+
 2010-12-07  Tassilo Horn  <tassilo@member.fsf.org>
 
 	* simple.el (just-one-space): Make argument n default to 1 if

lisp/files.el

@@ -3370,7 +3370,9 @@ ROOT is the root directory of the project.
 Return the new variables list."
   (let* ((file-name (buffer-file-name))
 	 (sub-file-name (if file-name
+                            ;; FIXME: Why not use file-relative-name?
 			    (substring file-name (length root)))))
+    (condition-case err
         (dolist (entry class-variables variables)
           (let ((key (car entry)))
             (cond
@@ -3379,13 +3381,18 @@ Return the new variables list."
               ;; want to filter all strings before the next condition.
               (when (and sub-file-name
                          (>= (length sub-file-name) (length key))
-		     (string= key (substring sub-file-name 0 (length key))))
+                         (string-prefix-p key sub-file-name))
                 (setq variables (dir-locals-collect-variables
                                  (cdr entry) root variables))))
              ((or (not key)
                   (derived-mode-p key))
               (setq variables (dir-locals-collect-mode-variables
-			   (cdr entry) variables))))))))
+                               (cdr entry) variables))))))
+      (error
+       ;; The file's content might be invalid (e.g. have a merge conflict), but
+       ;; that shouldn't prevent the user from opening the file.
+       (message ".dir-locals error: %s" (error-message-string err))
+       nil))))
 
 (defun dir-locals-set-directory-class (directory class &optional mtime)
   "Declare that the DIRECTORY root is an instance of CLASS.
@@ -3516,7 +3523,9 @@ and `file-local-variables-alist', without applying them."
 	  (dir-name nil))
       (cond
        ((stringp variables-file)
-	(setq dir-name (if (buffer-file-name) (file-name-directory (buffer-file-name)) default-directory))
+	(setq dir-name (if (buffer-file-name)
+                           (file-name-directory (buffer-file-name))
+                         default-directory))
 	(setq class (dir-locals-read-from-file variables-file)))
        ((consp variables-file)
 	(setq dir-name (nth 0 variables-file))
@@ -3826,21 +3835,25 @@ BACKUPNAME is the backup file name, which is the old file renamed."
   (and context
        (set-file-selinux-context to-name context)))
 
+(defvar file-name-version-regexp
+  "\\(?:~\\|\\.~[-[:alnum:]:#@^._]+~\\)"
+  "Regular expression matching the backup/version part of a file name.
+Used by `file-name-sans-versions'.")
+
 (defun file-name-sans-versions (name &optional keep-backup-version)
   "Return file NAME sans backup versions or strings.
 This is a separate procedure so your site-init or startup file can
 redefine it.
 If the optional argument KEEP-BACKUP-VERSION is non-nil,
-we do not remove backup version numbers, only true file version numbers."
+we do not remove backup version numbers, only true file version numbers.
+See also `file-name-version-regexp'."
   (let ((handler (find-file-name-handler name 'file-name-sans-versions)))
     (if handler
 	(funcall handler 'file-name-sans-versions name keep-backup-version)
       (substring name 0
-		 (if keep-backup-version
-		     (length name)
-		   (or (string-match "\\.~[-[:alnum:]:#@^._]+~\\'" name)
-		       (string-match "~\\'" name)
-		       (length name)))))))
+		 (unless keep-backup-version
+                   (string-match (concat file-name-version-regexp "\\'")
+                                 name))))))
 
 (defun file-ownership-preserved-p (file)
   "Return t if deleting FILE and rewriting it would preserve the owner."

lisp/jka-cmpr-hook.el

@@ -73,10 +73,18 @@ Otherwise, it is nil.")
 
 (defun jka-compr-build-file-regexp ()
   (purecopy
-  (mapconcat
-   'jka-compr-info-regexp
-   jka-compr-compression-info-list
-   "\\|")))
+   (let ((re-anchored '())
+         (re-free '()))
+     (dolist (e jka-compr-compression-info-list)
+       (let ((re (jka-compr-info-regexp e)))
+         (if (string-match "\\\\'\\'" re)
+             (push (substring re 0 (match-beginning 0)) re-anchored)
+           (push re re-free))))
+     (concat
+      (if re-free (concat (mapconcat 'identity re-free "\\|") "\\|"))
+      "\\(?:"
+      (mapconcat 'identity re-anchored "\\|")
+      "\\)" file-name-version-regexp "?\\'"))))
 
 ;; Functions for accessing the return value of jka-compr-get-compression-info
 (defun jka-compr-info-regexp               (info)  (aref info 0))
@@ -97,11 +105,9 @@ The determination as to which compression scheme, if any, to use is
 based on the filename itself and `jka-compr-compression-info-list'."
   (catch 'compression-info
     (let ((case-fold-search nil))
-      (mapc
-       (function (lambda (x)
+      (dolist (x jka-compr-compression-info-list)
         (and (string-match (jka-compr-info-regexp x) filename)
-			(throw 'compression-info x))))
-       jka-compr-compression-info-list)
+             (throw 'compression-info x)))
       nil)))
 
 (defun jka-compr-install ()
@@ -198,7 +204,7 @@ options through Custom does this automatically."
   ;; uncomp-message uncomp-prog uncomp-args
   ;; can-append strip-extension-flag file-magic-bytes]
   (mapcar 'purecopy
-  '(["\\.Z\\(~\\|\\.~[0-9]+~\\)?\\'"
+  '(["\\.Z\\'"
      "compressing"    "compress"     ("-c")
      ;; gzip is more common than uncompress. It can only read, not write.
      "uncompressing"  "gzip"   ("-c" "-q" "-d")
@@ -206,7 +212,7 @@ options through Custom does this automatically."
      ;; Formerly, these had an additional arg "-c", but that fails with
      ;; "Version 0.1pl2, 29-Aug-97." (RedHat 5.1 GNU/Linux) and
      ;; "Version 0.9.0b, 9-Sept-98".
-    ["\\.bz2\\(~\\|\\.~[0-9]+~\\)?\\'"
+    ["\\.bz2\\'"
      "bzip2ing"        "bzip2"         nil
      "bunzip2ing"      "bzip2"         ("-d")
      nil t "BZh"]
@@ -214,15 +220,15 @@ options through Custom does this automatically."
      "bzip2ing"        "bzip2"         nil
      "bunzip2ing"      "bzip2"         ("-d")
      nil nil "BZh"]
-    ["\\.\\(?:tgz\\|svgz\\|sifz\\)\\(~\\|\\.~[0-9]+~\\)?\\'"
+    ["\\.\\(?:tgz\\|svgz\\|sifz\\)\\'"
      "compressing"        "gzip"         ("-c" "-q")
      "uncompressing"      "gzip"         ("-c" "-q" "-d")
      t nil "\037\213"]
-    ["\\.g?z\\(~\\|\\.~[0-9]+~\\)?\\'"
+    ["\\.g?z\\'"
      "compressing"        "gzip"         ("-c" "-q")
      "uncompressing"      "gzip"         ("-c" "-q" "-d")
      t t "\037\213"]
-    ["\\.xz\\(~\\|\\.~[0-9]+~\\)?\\'"
+    ["\\.xz\\'"
      "XZ compressing"     "xz"           ("-c" "-q")
      "XZ uncompressing"   "xz"           ("-c" "-q" "-d")
      t t "\3757zXZ\0"]