* lisp/files.el: Make revert work with diff-buffer-with-file.

(diff-buffer-internal): New function extracted from diff-buffer-with-file
(diff-buffer-with-file): Use it.
* lisp/vc/diff.el (diff-into-buffer): New fun, extracted from diff.
(diff): Use it.

Fixes: debbugs:7277

3 files changed, 193 insertions, 163 deletions

diff --git a/lisp/ChangeLog b/lisp/ChangeLog
index 5353efa267a..4b76ea9c593 100644
--- a/lisp/ChangeLog
+++ b/lisp/ChangeLog
@@ -1,3 +1,11 @@
+2010-11-22  Bob Rogers  <rogers-emacs@rgrjr.dyndns.org>
+
+        * files.el: Make revert work with diff-buffer-with-file (bug#7277).
+        (diff-buffer-internal): New function extracted from diff-buffer-with-file
+        (diff-buffer-with-file): Use it.
+        * vc/diff.el (diff-into-buffer): New fun, extracted from diff.
+        (diff): Use it.
+
 2010-11-22  Tassilo Horn  <tassilo@member.fsf.org>
 
         * textmodes/reftex-ref.el (reftex-goto-label): Use the current
@@ -18,8 +26,8 @@
 
 2010-11-21  Deniz Dogan  <deniz.a.m.dogan@gmail.com>
 
-        * progmodes/python.el (python-font-lock-keywords): Highlight
-        top-level augmented assignments (Bug#6445).
+        * progmodes/python.el (python-font-lock-keywords):
+        Highlight top-level augmented assignments (Bug#6445).
 
 2010-11-21  Jan Djärv  <jan.h.d@swipnet.se>
 
@@ -922,22 +930,22 @@
         package-alist, to avoid loading inefficiencies.
         (package-built-in-p): Make VERSION optional, and treat it as a
         minimum acceptable version.
-        (package-activate): Search separately for built-in packages.  Emit
-        a warning if a dependency fails.
+        (package-activate): Search separately for built-in packages.
+        Emit a warning if a dependency fails.
         (define-package): Handle most common case, where there is no
         obsolete package, first.
         (package-compute-transaction): Print required version in error.
         (package--initialized): New variable.
         (list-packages): Use it.
         (package-initialize): Optional arg NO-ACTIVATE.  Don't put
-        built-in packages in packages-alist; keep it separate.  Set
-        package--initialized.
+        built-in packages in packages-alist; keep it separate.
+        Set package--initialized.
         (describe-package): Avoid activating packages as a side-effect.
         Search separately for built-in packages.
         (describe-package-1): Handle the case where an elpa package is
         simultaneously built-in and available/installed.
-        (package-installed-p, package--generate-package-list): Search
-        separately for built-in packages.
+        (package-installed-p, package--generate-package-list):
+        Search separately for built-in packages.
         (package-load-descriptor): Doc fix.
 
 2010-11-03  Stefan Monnier  <monnier@iro.umontreal.ca>
@@ -1084,8 +1092,8 @@
         * startup.el (command-line): Search for package directories, and
         don't load package.el if none are found.
 
-        * emacs-lisp/package.el (describe-package, list-packages): Call
-        package-initialize if it has not been called yet.
+        * emacs-lisp/package.el (describe-package, list-packages):
+        Call package-initialize if it has not been called yet.
 
 2010-10-30  Alan Mackenzie  <acm@muc.de>
 
@@ -1369,8 +1377,8 @@
         character pins, bug264.  Reported by Michael Laajanen.
         (verilog-auto-inst, verilog-read-decls, verilog-read-sub-decls)
         (verilog-read-sub-decls-in-interfaced, verilog-read-sub-decls-sig)
-        (verilog-subdecls-get-interfaced, verilog-subdecls-new): Support
-        interfaces with AUTOINST, bug270.  Reported by Luis Gutierrez.
+        (verilog-subdecls-get-interfaced, verilog-subdecls-new):
+        Support interfaces with AUTOINST, bug270.  Reported by Luis Gutierrez.
         (verilog-pretty-expr): Fix interactive arguments, bug272.
         Reported by Mark Johnson.
         (verilog-auto-tieoff, verilog-auto-tieoff-ignore-regexp):
@@ -1416,8 +1424,8 @@
         (verilog-auto-sense-sigs, verilog-read-always-signals)
         (verilog-read-always-signals-recurse): Fix loop indexes being
         AUTORESET. AUTORESET now assumes any variables in the
-        initialization section of a for() should be ignored.  Reported by
-        Dan Dever.
+        initialization section of a for() should be ignored.
+        Reported by Dan Dever.
         (verilog-error-font-lock-keywords)
         (verilog-error-regexp-emacs-alist)
         (verilog-error-regexp-xemacs-alist): Fix error detection of
@@ -1464,12 +1472,12 @@
         facemenu-read-color.  Require match in completion.  Doc fix.
 
         * facemenu.el (facemenu-read-color): Alias for read-color.
-        (facemenu-set-foreground, facemenu-set-background): Use
-        read-color.
+        (facemenu-set-foreground, facemenu-set-background):
+        Use read-color.
 
         * frame.el (set-background-color, set-foreground-color)
-        (set-cursor-color, set-mouse-color, set-border-color): Use
-        read-color.
+        (set-cursor-color, set-mouse-color, set-border-color):
+        Use read-color.
 
 2010-10-24  Leo  <sdl.web@gmail.com>
 
@@ -2463,8 +2471,8 @@
 
         * calendar/appt.el (appt-issue-message, appt-visible, appt-msg-window):
         Remove options, obsolete since 22.1.
-        (appt-display-format, appt-display-message): Remove
-        backwards-compatibility code.
+        (appt-display-format, appt-display-message):
+        Remove backwards-compatibility code.
         (appt-check): No longer check appt-issue-message.
         (appt-make-list): No longer autoload it.  Doc fix.  No longer
         activate the package.
@@ -3536,8 +3544,8 @@
         (tramp-compat-call-process): New defuns, moved from tramp.el.
 
         * net/tramp-fish.el (top) Require just 'tramp.  Add objects to
-        `tramp-methods' and `tramp-foreign-file-name-handler-alist'.  Add
-        to `tramp-unload-hook'.  Change call of
+        `tramp-methods' and `tramp-foreign-file-name-handler-alist'.
+        Add to `tramp-unload-hook'.  Change call of
         `tramp-compat-decimal-to-octal' to new function name.
         (tramp-fish-method): Make it a defconst.
         (tramp-fish-file-name-p): Make it a defsubst.
@@ -3572,8 +3580,8 @@
         (tramp-gw-open-connection): Set tramp-autoload cookie.
 
         * net/tramp-imap.el (top) Require just 'tramp.  Add objects to
-        `tramp-methods' and `tramp-foreign-file-name-handler-alist'.  Add
-        to `tramp-unload-hook'.  Change checks, whether package can be
+        `tramp-methods' and `tramp-foreign-file-name-handler-alist'.
+        Add to `tramp-unload-hook'.  Change checks, whether package can be
         loaded.
         (tramp-imap-file-name-p): Make it a defsubst.
         (tramp-imap-method, tramp-imaps-method)
@@ -3581,8 +3589,8 @@
         (tramp-imap-file-name-p): Set tramp-autoload cookie.
 
         * net/tramp-smb.el (top) Require just 'tramp.  Add objects to
-        `tramp-methods' and `tramp-foreign-file-name-handler-alist'.  Add
-        to `tramp-unload-hook'.  Change checks, whether package can be
+        `tramp-methods' and `tramp-foreign-file-name-handler-alist'.
+        Add to `tramp-unload-hook'.  Change checks, whether package can be
         loaded.  Change call of `tramp-compat-decimal-to-octal' to new
         function name.
         (tramp-smb-tunnel-method): Make it a defconst.
@@ -3788,12 +3796,12 @@
         * term/x-win.el: Update documentation for x-last-selected-text-*.
         (x-last-selected-text-cut, x-last-selected-text-cut-encoded)
         (x-last-cut-buffer-coding, x-cut-buffer-max): Remove.
-        (x-select-text): Remove argument PUSH, update documentation.  Remove
-        cut-buffer code.
+        (x-select-text): Remove argument PUSH, update documentation.
+        Remove cut-buffer code.
         (x-selection-value-internal): Was previously x-selection-value.
         (x-selection-value): Rename from x-cut-buffer-or-selection-value.
-        Update documentation, remove cut-buffer code.  Call
-        x-selection-value-internal.
+        Update documentation, remove cut-buffer code.
+        Call x-selection-value-internal.
         (x-clipboard-yank): Call x-selection-value-internal.
         (x-initialize-window-system): Remove setting of x-cut-buffer-max.
 
@@ -4124,8 +4132,8 @@
         (tramp-gvfs-handle-copy-file, tramp-gvfs-handle-rename-file):
         Implement backup call, when operation on local files fails.
         Use progress reporter.  Flush properties of changed files.
-        (tramp-gvfs-handle-delete-file): Add TRASH arg.  Use
-        `tramp-compat-delete-file'.
+        (tramp-gvfs-handle-delete-file): Add TRASH arg.
+        Use `tramp-compat-delete-file'.
         (tramp-gvfs-handle-expand-file-name): Expand "~/".
         (tramp-gvfs-handle-make-directory): Make more traces.
         (tramp-gvfs-handle-write-region): Protect deleting tmpfile.
@@ -4316,8 +4324,8 @@
         instead of whitespace-line-column (from EmacsWiki).  New version
         13.1.
         (whitespace-style): Added new value 'face.  Adjust docstring.
-        (whitespace-space, whitespace-hspace, whitespace-tab): Adjust
-        foreground property face.
+        (whitespace-space, whitespace-hspace, whitespace-tab):
+        Adjust foreground property face.
         (whitespace-line-column): Adjust docstring and type declaration.
         (whitespace-style-value-list, whitespace-toggle-option-alist)
         (whitespace-help-text): Adjust const initialization.
@@ -4345,8 +4353,8 @@
         (python-shell-prompt-alist)
         (python-shell-continuation-prompt-alist): New options.
         (python--set-prompt-regexp): New function.
-        (inferior-python-mode, run-python, python-shell): Require
-        ansi-color.  Use python--set-prompt-regexp to set the comint
+        (inferior-python-mode, run-python, python-shell):
+        Require ansi-color.  Use python--set-prompt-regexp to set the comint
         prompt based on the Python interpreter.
         (python--prompt-regexp): New var.
         (python-check-comint-prompt)
@@ -4932,16 +4940,16 @@
 
 2010-08-06  Alan Mackenzie  <bug-cc-mode@gnu.org>
 
-        * progmodes/cc-cmds.el (c-mask-paragraph, c-fill-paragraph): Fix
-        for the case that a C style comment has its delimiters alone on
+        * progmodes/cc-cmds.el (c-mask-paragraph, c-fill-paragraph):
+        Fix for the case that a C style comment has its delimiters alone on
         their respective lines.
 
 2010-08-06  Michael Albinus  <michael.albinus@gmx.de>
 
         * net/tramp.el (tramp-handle-start-file-process): Set connection
         property "vec".
-        (tramp-process-sentinel): Use it for flushing the cache.  We
-        cannot do it via the process buffer, the buffer could be deleted
+        (tramp-process-sentinel): Use it for flushing the cache.
+        We cannot do it via the process buffer, the buffer could be deleted
         already when running the sentinel.
 
 2010-08-06  Jürgen Hötzel  <juergen@archlinux.org>  (tiny change)
@@ -4955,11 +4963,11 @@
 
 2010-08-05  Eli Zaretskii  <eliz@gnu.org>
 
-        * emacs-lisp/find-gc.el (find-gc-source-files): Rename
-        unexec.c => unexcoff.c.
+        * emacs-lisp/find-gc.el (find-gc-source-files):
+        Rename unexec.c => unexcoff.c.
 
-        * emacs-lisp/authors.el (authors-fixed-entries): Rename
-        unexec.c => unexcoff.c.
+        * emacs-lisp/authors.el (authors-fixed-entries):
+        Rename unexec.c => unexcoff.c.
 
 2010-08-05  Michael Albinus  <michael.albinus@gmx.de>
 
@@ -5283,8 +5291,8 @@
 2010-07-20  Michael Albinus  <michael.albinus@gmx.de>
 
         * net/tramp.el (tramp-file-name-handler): Trace 'quit.
-        (tramp-open-connection-setup-interactive-shell): Apply
-        workaround for IRIX64 bug.  Move argument of last
+        (tramp-open-connection-setup-interactive-shell):
+        Apply workaround for IRIX64 bug.  Move argument of last
         `tramp-send-command' where it belongs to.
 
 2010-07-20  Michael Albinus  <michael.albinus@gmx.de>
@@ -5311,8 +5319,8 @@
 2010-07-18  Michael R. Mauger  <mmaug@yahoo.com>
 
         * progmodes/sql.el: Version 2.2.
-        (sql-product, sql-user, sql-database, sql-server, sql-port): Use
-        defcustom :safe keyword rather than putting safe-local-variable
+        (sql-product, sql-user, sql-database, sql-server, sql-port):
+        Use defcustom :safe keyword rather than putting safe-local-variable
         property.
         (sql-password): Use defcustom :risky keyword rather than putting
         risky-local-variable property.
@@ -5520,8 +5528,8 @@
 
 2010-07-10  Aleksei Gusev  <aleksei.gusev@gmail.com>  (tiny change)
 
-        * progmodes/compile.el (compilation-error-regexp-alist-alist): Add
-        regexps for cucumber and ruby.
+        * progmodes/compile.el (compilation-error-regexp-alist-alist):
+        Add regexps for cucumber and ruby.
 
 2010-07-08  Daiki Ueno  <ueno@unixuser.org>
 
@@ -5628,8 +5636,8 @@
 
         * faces.el (x-handle-named-frame-geometry)
         (x-handle-reverse-video, x-create-frame-with-faces)
-        (face-set-after-frame-default, tty-create-frame-with-faces): Don't
-        separately consult default-frame-alist.  It is now passed as the
+        (face-set-after-frame-default, tty-create-frame-with-faces):
+        Don't separately consult default-frame-alist.  It is now passed as the
         PARAMETER argument.
 
 2010-06-30  Andreas Schwab  <schwab@linux-m68k.org>
@@ -5654,8 +5662,8 @@
 
 2010-06-28  Jan Djärv  <jan.h.d@swipnet.se>
 
-        * dynamic-setting.el (font-setting-change-default-font): Remove
-        call to message.
+        * dynamic-setting.el (font-setting-change-default-font):
+        Remove call to message.
 
 2010-06-28  Kenichi Handa  <handa@m17n.org>
 
@@ -5907,8 +5915,8 @@
         (package-list-packages-internal): Check package-load-list.
         (package-load-descriptor, package-generate-autoloads)
         (package-unpack, package-unpack-single)
-        (package--read-archive-file, package-delete): Use
-        expand-file-name.
+        (package--read-archive-file, package-delete):
+        Use expand-file-name.
 
         * emacs-lisp/package-x.el: New file.  Package uploading
         functionality split out from package.el.
@@ -6027,7 +6035,7 @@
         appt-time-msg-list specify the warning time.
         (appt-add): Add new argument with the warning time.  (Bug#5176)
 
-2010-06-16  Bob Rogers  <rogers-emacs@rgrjr.dyndns.org>  (tiny change)
+2010-06-16  Bob Rogers  <rogers-emacs@rgrjr.dyndns.org>
 
         * vc/vc-svn.el (vc-svn-after-dir-status): Fix regexp for Subversions
         older than version 1.6.  (Bug#6361)
@@ -6039,15 +6047,15 @@
 
 2010-06-16  Agustín Martín  <agustin.martin@hispalinux.es>
 
-        * textmodes/ispell.el (ispell-dictionary-base-alist): Fix
-        portuguese casechars/not-casechars for missing 'çÇ'.
+        * textmodes/ispell.el (ispell-dictionary-base-alist):
+        Fix portuguese casechars/not-casechars for missing 'çÇ'.
         Suggested by Rolando Pereira (bug#6434).
 
 2010-06-15  Juanma Barranquero  <lekktu@gmail.com>
 
         * facemenu.el (list-colors-sort): Doc fix.
 
-2010-06-15  Bob Rogers  <rogers-emacs@rgrjr.dyndns.org>  (tiny change)
+2010-06-15  Bob Rogers  <rogers-emacs@rgrjr.dyndns.org>
 
         * progmodes/sql.el (sql-connect-mysql): Fix typo.
 
@@ -6527,8 +6535,8 @@
 
 2010-05-28  Michael Albinus  <michael.albinus@gmx.de>
 
-        * net/tramp-compat.el (tramp-compat-delete-file): Use
-        `symbol-value' for backward compatibility.
+        * net/tramp-compat.el (tramp-compat-delete-file):
+        Use `symbol-value' for backward compatibility.
 
         * net/tramp.el (tramp-handle-make-symbolic-link)
         (tramp-handle-load)
@@ -6546,15 +6554,15 @@
         (tramp-fish-handle-process-file): Use `delete-file' instead
         of `tramp-compat-delete-file'.
 
-        * net/tramp-ftp.el (tramp-ftp-file-name-handler): Use
-        `delete-file' instead of `tramp-compat-delete-file'.
+        * net/tramp-ftp.el (tramp-ftp-file-name-handler):
+        Use `delete-file' instead of `tramp-compat-delete-file'.
 
         * net/tramp-gvfs.el (tramp-gvfs-handle-delete-file): Rename arg.
         (tramp-gvfs-handle-write-region): Use `delete-file' instead of
         `tramp-compat-delete-file'.
 
-        * net/tramp-imap.el (tramp-imap-do-copy-or-rename-file): Use
-        `delete-file' instead of `tramp-compat-delete-file'.
+        * net/tramp-imap.el (tramp-imap-do-copy-or-rename-file):
+        Use `delete-file' instead of `tramp-compat-delete-file'.
 
         * net/tramp-smb.el (tramp-smb-handle-copy-file)
         (tramp-smb-handle-file-local-copy, tramp-smb-handle-rename-file)
@@ -6629,8 +6637,8 @@
 
 2010-05-27  Chong Yidong  <cyd@stupidchicken.com>
 
-        * progmodes/verilog-mode.el (verilog-type-font-keywords): Use
-        font-lock-constant-face, not obsolete font-lock-reference-face.
+        * progmodes/verilog-mode.el (verilog-type-font-keywords):
+        Use font-lock-constant-face, not obsolete font-lock-reference-face.
 
 2010-05-27  Kenichi Handa  <handa@m17n.org>
 
@@ -6714,8 +6722,8 @@
         * net/tramp.el (tramp-progress-reporter-update): New defun.
         (with-progress-reporter): Use it.
         (tramp-process-actions):
-        * net/tramp-gvfs.el (tramp-gvfs-handler-askquestion): Preserve
-        current message, in order to let progress reporter continue
+        * net/tramp-gvfs.el (tramp-gvfs-handler-askquestion):
+        Preserve current message, in order to let progress reporter continue
         afterwards.  (Bug#6257)
 
 2010-05-25  Glenn Morris  <rgm@gnu.org>
@@ -7019,8 +7027,8 @@
         * bindings.el (global-map): Bind them to right and left arrow keys.
 
         Don't override standard definition of convert-standard-filename.
-        * files.el (convert-standard-filename): Call
-        w32-convert-standard-filename and dos-convert-standard-filename on
+        * files.el (convert-standard-filename):
+        Call w32-convert-standard-filename and dos-convert-standard-filename on
         the corresponding systems.
 
         * w32-fns.el (w32-convert-standard-filename): Rename from
@@ -7520,8 +7528,8 @@
 
         * net/tramp-smb.el (tramp-smb-handle-delete-file): Add FORCE arg.
         (tramp-smb-handle-copy-file, tramp-smb-handle-file-local-copy)
-        (tramp-smb-handle-rename-file, tramp-smb-handle-write-region): Use
-        `tramp-compat-delete-file'.
+        (tramp-smb-handle-rename-file, tramp-smb-handle-write-region):
+        Use `tramp-compat-delete-file'.
 
 2010-05-05  Stefan Monnier  <monnier@iro.umontreal.ca>
 
@@ -9347,8 +9355,8 @@
 
 2010-02-21  Chong Yidong  <cyd@stupidchicken.com>
 
-        * files.el (directory-listing-before-filename-regexp): Use
-        stricter matching for iso-style dates, to avoid false matches with
+        * files.el (directory-listing-before-filename-regexp):
+        Use stricter matching for iso-style dates, to avoid false matches with
         date-like filenames (Bug#5597).
 
         * htmlfontify.el (htmlfontify): Doc fix.
@@ -9371,8 +9379,8 @@
 
 2010-02-19  Chong Yidong  <cyd@stupidchicken.com>
 
-        * isearch.el (isearch-update-post-hook, isearch-update): Revert
-        2010-02-17 change.
+        * isearch.el (isearch-update-post-hook, isearch-update):
+        Revert 2010-02-17 change.
 
 2010-02-19  Ulf Jasper  <ulf.jasper@web.de>
 
@@ -9838,8 +9846,8 @@
         (vc-git-toggle-signoff): Remove function.
         (vc-git-extra-menu-map): Do not bind vc-git-toggle-signoff.
 
-        * term/xterm.el (xterm-maybe-set-dark-background-mode): Rename
-        from xterm-set-background-mode.  Return t if the background mode
+        * term/xterm.el (xterm-maybe-set-dark-background-mode):
+        Rename from xterm-set-background-mode.  Return t if the background mode
         was set.
         (terminal-init-xterm): Move tty-set-up-initial-frame-faces
         earlier, call it again in case the background mode has changed.
@@ -10003,8 +10011,8 @@
 
 2010-01-16  Lennart Borgman  <lennart.borgman@gmail.com>
 
-        * nxml/nxml-mode.el (nxml-extend-after-change-region): Never
-        return t (Bug#3898).
+        * nxml/nxml-mode.el (nxml-extend-after-change-region):
+        Never return t (Bug#3898).
 
 2010-01-16  Frédéric Perrin  <frederic.perrin@resel.fr>  (tiny change)
 
@@ -10121,8 +10129,8 @@
 
 2010-01-12  Glenn Morris  <rgm@gnu.org>
 
-        * mail/emacsbug.el (report-emacs-bug-pretest-address): Set
-        it to bug-gnu-emacs rather than emacs-pretest-bug.
+        * mail/emacsbug.el (report-emacs-bug-pretest-address):
+        Set it to bug-gnu-emacs rather than emacs-pretest-bug.
 
 2010-01-11  Sam Steingold  <sds@gnu.org>
 
@@ -10436,8 +10444,8 @@
 2009-12-29  Dan Nicolaescu  <dann@ics.uci.edu>
 
         Make vc-dir work on subdirectories of the bzr root.
-        * vc-bzr.el (vc-bzr-after-dir-status): Add new argument.  Return
-        file names relative to it.
+        * vc-bzr.el (vc-bzr-after-dir-status): Add new argument.
+        Return file names relative to it.
         (vc-bzr-dir-status, vc-bzr-dir-status-files): Pass the bzr root
         relative directory to vc-bzr-after-dir-status.
 
@@ -10897,11 +10905,11 @@
         (tramp-methods, tramp-find-shell)
         (tramp-open-connection-setup-interactive-shell)
         (tramp-maybe-open-connection): Use it.
-        (tramp-shell-prompt-pattern, tramp-wait-for-output): Handle
-        existence of `#' and `$'.
+        (tramp-shell-prompt-pattern, tramp-wait-for-output):
+        Handle existence of `#' and `$'.
 
-        * net/tramp-fish.el (tramp-fish-maybe-open-connection): Use
-        `tramp-initial-end-of-output'.
+        * net/tramp-fish.el (tramp-fish-maybe-open-connection):
+        Use `tramp-initial-end-of-output'.
 
 2009-12-07  Dan Nicolaescu  <dann@ics.uci.edu>
 
@@ -10959,13 +10967,13 @@
 
 2009-12-06  Ulf Jasper  <ulf.jasper@web.de>
 
-        * xml.el (xml-substitute-numeric-entities): Move
-        newsticker--decode-numeric-entities in newst-backend.el to
+        * xml.el (xml-substitute-numeric-entities):
+        Move newsticker--decode-numeric-entities in newst-backend.el to
         xml-substitute-numeric-entities in xml.el.  (Bug#5008)
         * net/newst-backend.el (newsticker--parse-generic-feed)
         (newsticker--parse-generic-items)
-        (newsticker--decode-numeric-entities): Move
-        newsticker--decode-numeric-entities in newst-backend.el to
+        (newsticker--decode-numeric-entities):
+        Move newsticker--decode-numeric-entities in newst-backend.el to
         xml-substitute-numeric-entities in xml.el.  (Bug#5008)
 
 2009-12-06  Daniel Colascione  <dan.colascione@gmail.com>
@@ -11028,8 +11036,8 @@
 
 2009-12-05  Kevin Ryde  <user42@zip.com.au>
 
-        * textmodes/sgml-mode.el (sgml-lexical-context): Recognise
-        comment-start-skip to comment-end-skip as comment (Bug#4781).
+        * textmodes/sgml-mode.el (sgml-lexical-context):
+        Recognise comment-start-skip to comment-end-skip as comment (Bug#4781).
 
 2009-12-05  Juri Linkov  <juri@jurta.org>
 
@@ -11486,8 +11494,8 @@
         (doc-view-scroll-up-or-next-page)
         (doc-view-scroll-down-or-previous-page)
         (doc-view-next-line-or-next-page)
-        (doc-view-previous-line-or-previous-page): Rename
-        `doc-view-continuous-mode' to `doc-view-continuous'.  (Bug#4896)
+        (doc-view-previous-line-or-previous-page):
+        Rename `doc-view-continuous-mode' to `doc-view-continuous'.  (Bug#4896)
 
 2009-11-30  Juri Linkov  <juri@jurta.org>
 
@@ -11689,8 +11697,8 @@
 
         (verilog-auto-inst, verilog-auto-star-safe)
         (verilog-delete-auto-star-implicit, verilog-read-sub-decls):
-        Fix removing "// Interfaces" when saving .* expansions.  Reported by
-        Pierre-David Pfister.
+        Fix removing "// Interfaces" when saving .* expansions.
+        Reported by Pierre-David Pfister.
 
 2009-11-26  Glenn Morris  <rgm@gnu.org>
 
@@ -12868,12 +12876,12 @@
         (tramp-compat-delete-directory): New defuns.
 
         * net/tramp-fish.el (tramp-fish-handle-delete-directory):
-        * net/tramp-gvfs.el (tramp-gvfs-handle-delete-directory): Use
-        `tramp-compat-delete-directory'.
+        * net/tramp-gvfs.el (tramp-gvfs-handle-delete-directory):
+        Use `tramp-compat-delete-directory'.
 
         * net/tramp-smb.el (tramp-smb-handle-copy-directory)
-        (tramp-smb-handle-delete-directory): Use
-        `tramp-compat-copy-directory' and `tramp-compat-delete-directory'.
+        (tramp-smb-handle-delete-directory):
+        Use `tramp-compat-copy-directory' and `tramp-compat-delete-directory'.
 
         * net/trampver.el: Update release number.
 
@@ -13225,11 +13233,11 @@
 
 2009-10-31  Chong Yidong  <cyd@stupidchicken.com>
 
-        * international/mule-diag.el (list-character-sets-1): Minor
-        message fix (Bug#3526).
+        * international/mule-diag.el (list-character-sets-1):
+        Minor message fix (Bug#3526).
 
-        * progmodes/etags.el (etags-list-tags, etags-tags-apropos): Fix
-        face property (Bug#4834).
+        * progmodes/etags.el (etags-list-tags, etags-tags-apropos):
+        Fix face property (Bug#4834).
         (etags-list-tags, etags-tags-apropos-additional)
         (etags-tags-apropos, tags-select-tags-table): Add follow-link
         property.
@@ -13726,8 +13734,8 @@
 
 2009-10-23  Jay Belanger  <jay.p.belanger@gmail.com>
 
-        * calc/calc.el (math-read-number, math-read-number-simple): Use
-        `save-match-data'.
+        * calc/calc.el (math-read-number, math-read-number-simple):
+        Use `save-match-data'.
 
 2009-10-22  Stefan Monnier  <monnier@iro.umontreal.ca>
 
@@ -15042,8 +15050,8 @@
 
 2009-09-26  Alan Mackenzie  <acm@muc.de>
 
-        * progmodes/cc-engine.el (c-beginning-of-statement-1): Correct
-        buggy bracketing.  (Bug#4289)
+        * progmodes/cc-engine.el (c-beginning-of-statement-1):
+        Correct buggy bracketing.  (Bug#4289)
 
         * progmodes/cc-langs.el (c-nonlabel-token-key): Allow quoted
         character constants (as case labels).  (Bug#4289)
@@ -15426,8 +15434,8 @@
 
 2009-09-21  Chong Yidong  <cyd@stupidchicken.com>
 
-        * files.el (conf-mode-maybe, magic-fallback-mode-alist): Use
-        nxml-mode instead of xml-mode.
+        * files.el (conf-mode-maybe, magic-fallback-mode-alist):
+        Use nxml-mode instead of xml-mode.
 
 2009-09-21  Kevin Ryde  <user42@zip.com.au>
 
@@ -16248,8 +16256,8 @@
         * net/tramp.el (tramp-handle-insert-directory): Handle "--dired"
         also when adding a new directory.
 
-        * net/tramp-compat.el (tramp-compat-line-beginning-position): New
-        defun.
+        * net/tramp-compat.el (tramp-compat-line-beginning-position):
+        New defun.
 
 2009-09-04  Stefan Monnier  <monnier@iro.umontreal.ca>
 
@@ -17576,8 +17584,8 @@
         (gdb-control-current-thread): Interactive setters for
         `gdb-gud-control-all-threads' to use in menu.
         (gdb-show-run-p): Show «Go» when process is not active.
-        (gud-tool-bar-map): Add non-stop/A,T indicator.  Uses
-        gud/thread.xpm and gud/all.xpm.
+        (gud-tool-bar-map): Add non-stop/A,T indicator.
+        Uses gud/thread.xpm and gud/all.xpm.
 
 2009-08-08  Yoni Rabkin  <yoni@rabkins.net>
 
@@ -17601,8 +17609,8 @@
         (gdb-breakpoints-mode-map): Don't assume threads buffer is present.
         (gdb-threads-mode-map): Don't assume breakpoints buffer is present.
         (gdb-disassembly-handler-custom, gdb-stack-list-frames-custom)
-        (gdb-locals-handler-custom, gdb-registers-handler-custom): Thread
-        info in mode name.
+        (gdb-locals-handler-custom, gdb-registers-handler-custom):
+        Thread info in mode name.
         (gdb-registers-mode-map): TAB to switch to locals.
 
 2009-08-08  Eli Zaretskii  <eliz@gnu.org>
@@ -17617,14 +17625,14 @@
 
 2009-08-07  Eli Zaretskii  <eliz@gnu.org>
 
-        * mail/sendmail.el (mail-yank-original): Set
-        buffer-file-coding-system from the one used by the message whose
+        * mail/sendmail.el (mail-yank-original):
+        Set buffer-file-coding-system from the one used by the message whose
         text is yanked.
 
         * calc/calc-graph.el (calc-graph-plot): Set calc-graph-last-device
         to "windows" when "pgnuplot" is used.
-        (calc-graph-command, calc-gnuplot-command, calc-graph-init): Don't
-        call accept-process-output if "pgnuplot" is used.
+        (calc-graph-command, calc-gnuplot-command, calc-graph-init):
+        Don't call accept-process-output if "pgnuplot" is used.
         (calc-graph-init): Don't send -display and -geometry to
         "pgnuplot".  If "pgnuplot" is used, glean gnuplot version by
         running "pgnuplot -V" with shell-command-to-string.
@@ -17764,11 +17772,11 @@
         * progmodes/gdb-mi.el (gdb-thread-number): Initialize with nil.
         (gdb-current-context-command): Do not append --thread if
         `gdb-thread-number' is nil.
-        (gdb-running-threads-count, gdb-stopped-threads-count): New
-        variables.
+        (gdb-running-threads-count, gdb-stopped-threads-count):
+        New variables.
         (gdb-non-stop, gdb-gud-control-all-threads, gdb-switch-reasons)
-        (gdb-stopped-hooks, gdb-switch-when-another-stopped): New
-        customization options.
+        (gdb-stopped-hooks, gdb-switch-when-another-stopped):
+        New customization options.
         (gdb-gud-context-command, gdb-gud-context-call): New wrappers for
         GUD commands.
         (gdb): `gud-def' definitions changed to use `gdb-gud-context-call'.
@@ -17892,8 +17900,8 @@
         * net/tramp-cache.el (tramp-cache-inhibit-cache): New defvar.
         (tramp-get-file-property): Use it.
 
-        * autorevert.el (auto-revert-handler): Allow
-        `auto-revert-tail-mode' for remote files.
+        * autorevert.el (auto-revert-handler):
+        Allow `auto-revert-tail-mode' for remote files.
 
 2009-08-02  Jason Rumney  <jasonr@gnu.org>
 
@@ -17903,8 +17911,8 @@
 2009-08-02  Chong Yidong  <cyd@stupidchicken.com>
 
         * font-lock.el (font-lock-string-face, font-lock-builtin-face)
-        (font-lock-variable-name-face, font-lock-constant-face): Darken
-        the colors for light backgrounds.
+        (font-lock-variable-name-face, font-lock-constant-face):
+        Darken the colors for light backgrounds.
 
 2009-08-01  Eli Zaretskii  <eliz@gnu.org>
 
@@ -18004,8 +18012,8 @@
 
         * net/zeroconf.el (zeroconf-init): Check for "GetVersionString"
         instead of "IsNSSSupportAvailable".  Avahi ought to work also when
-        "IsNSSSupportAvailable" method is not available.  Reported by
-        Steve Youngs <steve@sxemacs.org>.
+        "IsNSSSupportAvailable" method is not available.
+        Reported by Steve Youngs <steve@sxemacs.org>.
 
 2009-07-24  Kenichi Handa  <handa@m17n.org>
 
@@ -18130,11 +18138,11 @@
 
 2009-07-21  Chong Yidong  <cyd@stupidchicken.com>
 
-        * mail/rmailedit.el (rmail-edit-mode): Use
-        auto-save-include-big-deletions.
+        * mail/rmailedit.el (rmail-edit-mode):
+        Use auto-save-include-big-deletions.
 
-        * mail/rmail.el (rmail-variables): Use
-        auto-save-include-big-deletions.
+        * mail/rmail.el (rmail-variables):
+        Use auto-save-include-big-deletions.
 
         * files.el (auto-save-mode): Revert 2009-07-21 and 2009-07-16
         changes.
@@ -18310,8 +18318,8 @@
         * w32-fns.el (x-selection-owner-p): New function.
 
         * mouse.el (mouse-drag-track): Call deactivate-mark earlier.
-        (mouse-yank-at-click, mouse-yank-primary): If
-        select-active-regions is non-nil, deactivate the mark before
+        (mouse-yank-at-click, mouse-yank-primary):
+        If select-active-regions is non-nil, deactivate the mark before
         insertion.
 
         * simple.el (deactivate-mark, set-mark): Only save selection if we
@@ -18380,11 +18388,11 @@
 
         * select.el (x-set-selection): Doc fix.
         (x-valid-simple-selection-p): Allow buffer values.
-        (xselect--selection-bounds): Handle buffer values.  Suggested by
-        David De La Harpe Golden.
+        (xselect--selection-bounds): Handle buffer values.
+        Suggested by David De La Harpe Golden.
 
-        * mouse.el (mouse-set-region, mouse-drag-track): Call
-        copy-region-as-kill before setting the mark, to let
+        * mouse.el (mouse-set-region, mouse-drag-track):
+        Call copy-region-as-kill before setting the mark, to let
         select-active-regions work.
 
 2009-07-15  David De La Harpe Golden  <david@harpegolden.net>
@@ -18586,8 +18594,8 @@
         * progmodes/gdb-mi.el: Port memory buffer from gdb-ui.el.
         (gdb-memory-address): New variable which holds top address of
         memory page shown in memory buffer.
-        (gdb-memory-repeat-count, gdb-memory-format, gdb-memory-unit): New
-        customization variables.
+        (gdb-memory-repeat-count, gdb-memory-format, gdb-memory-unit):
+        New customization variables.
         New functions:
         (gdb-display-memory-buffer, gdb-frame-memory-buffer): Functions to
         display the memory buffer.
@@ -18600,8 +18608,8 @@
         (gdb-memory-unit-word, gdb-memory-unit-halfword)
         (gdb-memory-unit-giant, gdb-memory-unit-byte): Functions to set
         unit size used in memory buffer.
-        (gdb-memory-show-next-page, gdb-memory-show-previous-page): Switch
-        to next/previous page of memory buffer.
+        (gdb-memory-show-next-page, gdb-memory-show-previous-page):
+        Switch to next/previous page of memory buffer.
         Now using (bindat-get-field) instead of fadr functions.
 
 2009-07-07  Sam Steingold  <sds@gnu.org>
@@ -18611,8 +18619,8 @@
 
 2009-07-07  Kenichi Handa  <handa@m17n.org>
 
-        * international/mule-cmds.el (reset-language-environment): Put
-        the highset priority to the charset iso-8859-1.
+        * international/mule-cmds.el (reset-language-environment):
+        Put the highset priority to the charset iso-8859-1.
 
 2009-07-06  Chong Yidong  <cyd@stupidchicken.com>
 
@@ -18642,8 +18650,8 @@
         (woman-file-name, woman2-format-paragraphs)
         (woman-leave-blank-lines): Code cleanup.
         (woman-use-own-frame): Change default to nil.
-        (woman-italic, woman-bold, woman-unknown, woman-addition): Change
-        defaults to inherit from default faces.
+        (woman-italic, woman-bold, woman-unknown, woman-addition):
+        Change defaults to inherit from default faces.
         (woman2-process-escapes): Consume the newline after a stand-alone
         filler character (Bug#3651).
 
@@ -18937,8 +18945,8 @@
         (verilog-auto-ascii-enum): Support one-hot state machines in
         AUTOASCIIENUM.  Suggested by Lloyd Gomez.
         (verilog-auto-inst, verilog-auto-inst-port): Include interface
-        modport in AUTOINST and add vl-modport for users.  Reported by
-        David Rogoff.
+        modport in AUTOINST and add vl-modport for users.
+        Reported by David Rogoff.
         (verilog-auto-inout-module, verilog-auto-inst)
         (verilog-decls-get-interfaces, verilog-insert-definition)
         (verilog-insert-one-definition, verilog-read-decls)
diff --git a/lisp/files.el b/lisp/files.el
index 42a3f87cb11..4513045e5c2 100644
--- a/lisp/files.el
+++ b/lisp/files.el
@@ -4491,24 +4491,42 @@ Before and after saving the buffer, this function runs
   "View the differences between BUFFER and its associated file.
 This requires the external program `diff' to be in your `exec-path'."
   (interactive "bBuffer: ")
-  (with-current-buffer (get-buffer (or buffer (current-buffer)))
+  (diff-buffer-internal (get-buffer (or buffer (current-buffer)))
+                        (get-buffer-create "*Diff*"))
+  ;; return always nil, so that save-buffers-kill-emacs will not move
+  ;; over to the next unsaved buffer when calling `d'.
+  nil)
+
+(defvar diff-buffer-buffer)     ;; suppress compiler warnings.
+
+(defun diff-buffer-internal (buffer result-buffer)
+  (if (not (and buffer (buffer-name buffer)))
+      (error "Original buffer deleted."))
+  (with-current-buffer buffer
     (if (and buffer-file-name
              (file-exists-p buffer-file-name))
         (let ((tempfile (make-temp-file "buffer-content-")))
           (unwind-protect
               (progn
                 (write-region nil nil tempfile nil 'nomessage)
-                (diff buffer-file-name tempfile nil t)
-                (sit-for 0))
+                ;; No asynch so we don't delete the temp file prematurely.
+                (diff-into-buffer result-buffer buffer-file-name tempfile
+                                  nil t)
+                (sit-for 0)
+                ;; Now revise the revert-buffer-function, since the
+                ;; default will not be able to find the temp file.
+                (with-current-buffer result-buffer
+                  (set (make-local-variable 'diff-buffer-buffer) buffer)
+                  (setq revert-buffer-function
+                        (lambda (ignore-auto noconfirm)
+                          (diff-buffer-internal diff-buffer-buffer
+                                                (current-buffer))))))
             (when (file-exists-p tempfile)
               (delete-file tempfile))))
       (message "Buffer %s has no associated file on disc" (buffer-name))
       ;; Display that message for 1 second so that user can read it
       ;; in the minibuffer.
-      (sit-for 1)))
-  ;; return always nil, so that save-buffers-kill-emacs will not move
-  ;; over to the next unsaved buffer when calling `d'.
-  nil)
+      (sit-for 1))))
 
 (defvar save-some-buffers-action-alist
   `((?\C-r
diff --git a/lisp/vc/diff.el b/lisp/vc/diff.el
index e79e72c8b0d..1a835b59994 100644
--- a/lisp/vc/diff.el
+++ b/lisp/vc/diff.el
@@ -108,11 +108,16 @@ specified in `diff-switches' are passed to the diff command."
                   (read-file-name "Diff original file: "
                                   (file-name-directory newf) nil t)))
      (list oldf newf (diff-switches))))
+  (diff-into-buffer nil old new switches no-async))
+
+(defun diff-into-buffer (buf old new &optional switches no-async)
+  ;; Noninteractive helper for creating and reverting diff buffers.
   (setq new (expand-file-name new)
         old (expand-file-name old))
   (or switches (setq switches diff-switches)) ; If not specified, use default.
+  (or buf (setq buf (get-buffer-create "*Diff*")))
   (let* ((old-alt (file-local-copy old))
-        (new-alt (file-local-copy new))
+         (new-alt (file-local-copy new))
          (command
           (mapconcat 'identity
                      `(,diff-command
@@ -123,7 +128,6 @@ specified in `diff-switches' are passed to the diff command."
                        ,(shell-quote-argument (or old-alt old))
                        ,(shell-quote-argument (or new-alt new)))
                      " "))
-         (buf (get-buffer-create "*Diff*"))
          (thisdir default-directory)
          proc)
     (save-excursion