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;;; ediff.el --- a comprehensive visual interface to diff & patch
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;; Copyright (C) 1994-2013 Free Software Foundation, Inc.
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;; Author: Michael Kifer <kifer@cs.stonybrook.edu>
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;; Created: February 2, 1994
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;; Keywords: comparing, merging, patching, vc, tools, unix
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;; Version: 2.81.4
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;; Yoni Rabkin <yoni@rabkins.net> contacted the maintainer of this
;; file on 20/3/2008, and the maintainer agreed that when a bug is
;; filed in the Emacs bug reporting system against this file, a copy
;; of the bug report be sent to the maintainer's email address.

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(defconst ediff-version "2.81.5" "The current version of Ediff")
(defconst ediff-date "July 4, 2013" "Date of last update")
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;; This file is part of GNU Emacs.

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;; GNU Emacs is free software: you can redistribute it and/or modify
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;; it under the terms of the GNU General Public License as published by
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;; the Free Software Foundation, either version 3 of the License, or
;; (at your option) any later version.
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;; GNU Emacs is distributed in the hope that it will be useful,
;; but WITHOUT ANY WARRANTY; without even the implied warranty of
;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
;; GNU General Public License for more details.

;; You should have received a copy of the GNU General Public License
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;; along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.
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;;; Commentary:

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;; Never read that diff output again!
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;; Apply patch interactively!
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;; Merge with ease!
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;; This package provides a convenient way of simultaneous browsing through
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;; the differences between a pair (or a triple) of files or buffers.  The
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;; files being compared, file-A, file-B, and file-C (if applicable) are
;; shown in separate windows (side by side, one above the another, or in
;; separate frames), and the differences are highlighted as you step
;; through them.  You can also copy difference regions from one buffer to
;; another (and recover old differences if you change your mind).
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;; Ediff also supports merging operations on files and buffers, including
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;; merging using ancestor versions.  Both comparison and merging operations can
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;; be performed on directories, i.e., by pairwise comparison of files in those
;; directories.

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;; In addition, Ediff can apply a patch to a file and then let you step
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;; though both files, the patched and the original one, simultaneously,
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;; difference-by-difference.  You can even apply a patch right out of a
;; mail buffer, i.e., patches received by mail don't even have to be saved.
;; Since Ediff lets you copy differences between buffers, you can, in
;; effect, apply patches selectively (i.e., you can copy a difference
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;; region from file_orig to file, thereby undoing any particular patch that
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;; you don't like).

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;; Ediff is aware of version control, which lets the user compare
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;; files with their older versions.  Ediff can also work with remote and
;; compressed files.  Details are given below.
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;; Finally, Ediff supports directory-level comparison, merging and patching.
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;; See the on-line manual for details.
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;; This package builds upon the ideas borrowed from emerge.el and several
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;; Ediff's functions are adaptations from emerge.el.  Much of the functionality
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;; Ediff provides is also influenced by emerge.el.

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;; The present version of Ediff supersedes Emerge.  It provides a superior user
;; interface and has numerous major features not found in Emerge.  In
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;; particular, it can do patching, and 2-way and 3-way file comparison,
;; merging, and directory operations.
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;;; Bugs:

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;;  1. The undo command doesn't restore deleted regions well.  That is, if
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;;  you delete all characters in a difference region and then invoke
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;;  `undo', the reinstated text will most likely be inserted outside of
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;;  what Ediff thinks is the current difference region. (This problem
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;;  doesn't seem to exist with XEmacs.)
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;;
;;  If at any point you feel that difference regions are no longer correct,
;;  you can hit '!' to recompute the differences.

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;;  2. On a monochrome display, the repertoire of faces with which to
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;;  highlight fine differences is limited.  By default, Ediff is using
;;  underlining.  However, if the region is already underlined by some other
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;;  overlays, there is no simple way to temporarily remove that residual
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;;  underlining.  This problem occurs when a buffer is highlighted with
;;  hilit19.el or font-lock.el packages.  If this residual highlighting gets
;;  in the way, you can do the following.  Both font-lock.el and hilit19.el
;;  provide commands for unhighlighting buffers.  You can either place these
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;;  commands in `ediff-prepare-buffer-hook' (which will unhighlight every
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;;  buffer used by Ediff) or you can execute them interactively, at any time
;;  and on any buffer.
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;;; Acknowledgments:
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;; Ediff was inspired by Dale R. Worley's <drw@math.mit.edu> emerge.el.
;; Ediff would not have been possible without the help and encouragement of
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;; its many users.  See Ediff on-line Info for the full list of those who
;; helped.  Improved defaults in Ediff file-name reading commands.
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;;; Code:

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(provide 'ediff)
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;; Compiler pacifier
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(eval-and-compile
  (unless (fboundp 'declare-function) (defmacro declare-function (&rest  r))))

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(require 'ediff-util)
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;; end pacifier

(require 'ediff-init)
(require 'ediff-mult)  ; required because of the registry stuff

(defgroup ediff nil
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  "Comprehensive visual interface to `diff' and `patch'."
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  :tag "Ediff"
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  :group 'tools)


(defcustom ediff-use-last-dir nil
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  "If t, Ediff will use previous directory as default when reading file name."
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  :type 'boolean
  :group 'ediff)
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;; Last directory used by an Ediff command for file-A.
(defvar ediff-last-dir-A nil)
;; Last directory used by an Ediff command for file-B.
(defvar ediff-last-dir-B nil)
;; Last directory used by an Ediff command for file-C.
(defvar ediff-last-dir-C nil)
;; Last directory used by an Ediff command for the ancestor file.
(defvar ediff-last-dir-ancestor nil)
;; Last directory used by an Ediff command as the output directory for merge.
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(defvar ediff-last-merge-autostore-dir nil)
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;; Used as a startup hook to set `_orig' patch file read-only.
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(defun ediff-set-read-only-in-buf-A ()
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  (ediff-with-current-buffer ediff-buffer-A
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    (setq buffer-read-only t)))
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(declare-function dired-get-filename "dired"
                  (&optional localp no-error-if-not-filep))
(declare-function dired-get-marked-files "dired"
                  (&optional localp arg filter distinguish-one-marked))

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;; Return a plausible default for ediff's first file:
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;; In dired, return the file number FILENO (or 0) in the list
;; (all-selected-files, filename under the cursor), where directories are
;; ignored. Otherwise, return DEFAULT file name, if non-nil. Else,
;; if the buffer is visiting a file, return that file name.
(defun ediff-get-default-file-name (&optional default fileno)
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  (cond ((eq major-mode 'dired-mode)
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	 (let ((current (dired-get-filename nil 'no-error))
	       (marked (condition-case nil
			   (dired-get-marked-files 'no-dir)
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			 (error nil)))
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	       aux-list choices result)
	   (or (integerp fileno) (setq fileno 0))
	   (if (stringp default)
	       (setq aux-list (cons default aux-list)))
	   (if (and (stringp current) (not (file-directory-p current)))
	       (setq aux-list (cons current aux-list)))
	   (setq choices (nconc  marked aux-list))
	   (setq result (elt choices fileno))
	   (or result
	       default)))
	((stringp default) default)
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	((buffer-file-name (current-buffer))
	 (file-name-nondirectory (buffer-file-name (current-buffer))))
	))

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;;; Compare files/buffers
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;;;###autoload
(defun ediff-files (file-A file-B &optional startup-hooks)
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  "Run Ediff on a pair of files, FILE-A and FILE-B."
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  (interactive
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   (let ((dir-A (if ediff-use-last-dir
		    ediff-last-dir-A
		  default-directory))
	 dir-B f)
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     (list (setq f (ediff-read-file-name
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		    "File A to compare"
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		    dir-A
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		    (ediff-get-default-file-name)
		    'no-dirs))
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	   (ediff-read-file-name "File B to compare"
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				 (setq dir-B
				       (if ediff-use-last-dir
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					   ediff-last-dir-B
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					 (file-name-directory f)))
				 (progn
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				   (ediff-add-to-history
				    'file-name-history
				    (ediff-abbreviate-file-name
				     (expand-file-name
				      (file-name-nondirectory f)
				      dir-B)))
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				   (ediff-get-default-file-name f 1)))
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	   )))
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  (ediff-files-internal file-A
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			(if (file-directory-p file-B)
			    (expand-file-name
			     (file-name-nondirectory file-A) file-B)
			  file-B)
			nil ; file-C
			startup-hooks
			'ediff-files))
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;;;###autoload
(defun ediff-files3 (file-A file-B file-C &optional startup-hooks)
  "Run Ediff on three files, FILE-A, FILE-B, and FILE-C."
  (interactive
   (let ((dir-A (if ediff-use-last-dir
		    ediff-last-dir-A
		  default-directory))
	 dir-B dir-C f ff)
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     (list (setq f (ediff-read-file-name
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		    "File A to compare"
		    dir-A
		    (ediff-get-default-file-name)
		    'no-dirs))
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	   (setq ff (ediff-read-file-name "File B to compare"
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					  (setq dir-B
						(if ediff-use-last-dir
						    ediff-last-dir-B
						  (file-name-directory f)))
					  (progn
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					    (ediff-add-to-history
					     'file-name-history
					     (ediff-abbreviate-file-name
					      (expand-file-name
					       (file-name-nondirectory f)
					       dir-B)))
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					    (ediff-get-default-file-name f 1))))
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	   (ediff-read-file-name "File C to compare"
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				 (setq dir-C (if ediff-use-last-dir
						 ediff-last-dir-C
					       (file-name-directory ff)))
				 (progn
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				   (ediff-add-to-history
				    'file-name-history
				    (ediff-abbreviate-file-name
				     (expand-file-name
				      (file-name-nondirectory ff)
				      dir-C)))
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				   (ediff-get-default-file-name ff 2)))
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	   )))
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  (ediff-files-internal file-A
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			(if (file-directory-p file-B)
			    (expand-file-name
			     (file-name-nondirectory file-A) file-B)
			  file-B)
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			(if (file-directory-p file-C)
			    (expand-file-name
			     (file-name-nondirectory file-A) file-C)
			  file-C)
			startup-hooks
			'ediff-files3))
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;;;###autoload
(defalias 'ediff3 'ediff-files3)
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(defun ediff-find-file (file-var buffer-name &optional last-dir hooks-var)
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  "Visit FILE and arrange its buffer to Ediff's liking.
FILE-VAR is actually a variable symbol whose value must contain a true
file name.
BUFFER-NAME is a variable symbol, which will get the buffer object into
which FILE is read.
LAST-DIR is the directory variable symbol where FILE's
directory name should be returned.  HOOKS-VAR is a variable symbol that will
be assigned the hook to be executed after `ediff-startup' is finished.
`ediff-find-file' arranges that the temp files it might create will be
deleted."
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  (let* ((file (symbol-value file-var))
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	 (file-magic (ediff-filename-magic-p file))
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	 (temp-file-name-prefix (file-name-nondirectory file)))
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    (cond ((not (file-readable-p file))
	   (error "File `%s' does not exist or is not readable" file))
	  ((file-directory-p file)
	   (error "File `%s' is a directory" file)))
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    ;; some of the commands, below, require full file name
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    (setq file (expand-file-name file))
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    ;; Record the directory of the file
    (if last-dir
	(set last-dir (expand-file-name (file-name-directory file))))
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    ;; Setup the buffer
    (set buffer-name (find-file-noselect file))
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    (ediff-with-current-buffer (symbol-value buffer-name)
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      (widen) ; Make sure the entire file is seen
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      (cond (file-magic  ;   file has a handler, such as jka-compr-handler or
	     		 ;;; ange-ftp-hook-function--arrange for temp file
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	     (ediff-verify-file-buffer 'magic)
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	     (setq file
		   (ediff-make-temp-file
		    (current-buffer) temp-file-name-prefix))
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	     (set hooks-var (cons `(lambda () (delete-file ,file))
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				  (symbol-value hooks-var))))
	    ;; file processed via auto-mode-alist, a la uncompress.el
	    ((not (equal (file-truename file)
			 (file-truename (buffer-file-name))))
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	     (setq file
		   (ediff-make-temp-file
		    (current-buffer) temp-file-name-prefix))
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	     (set hooks-var (cons `(lambda () (delete-file ,file))
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				  (symbol-value hooks-var))))
	    (t ;; plain file---just check that the file matches the buffer
	     (ediff-verify-file-buffer))))
    (set file-var file)))

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;; MERGE-BUFFER-FILE is the file to be associated with the merge buffer
(defun ediff-files-internal (file-A file-B file-C startup-hooks job-name
				    &optional merge-buffer-file)
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  (let (buf-A buf-B buf-C)
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    (if (string= file-A file-B)
	(error "Files A and B are the same"))
    (if (stringp file-C)
	(or (and (string= file-A file-C) (error "Files A and C are the same"))
	    (and (string= file-B file-C) (error "Files B and C are the same"))))
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    (message "Reading file %s ... " file-A)
    ;;(sit-for 0)
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    (ediff-find-file 'file-A 'buf-A 'ediff-last-dir-A 'startup-hooks)
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    (message "Reading file %s ... " file-B)
    ;;(sit-for 0)
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    (ediff-find-file 'file-B 'buf-B 'ediff-last-dir-B 'startup-hooks)
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    (if (stringp file-C)
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	(progn
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	  (message "Reading file %s ... " file-C)
	  ;;(sit-for 0)
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	  (ediff-find-file
	   'file-C 'buf-C
	   (if (eq job-name 'ediff-merge-files-with-ancestor)
	       'ediff-last-dir-ancestor 'ediff-last-dir-C)
	   'startup-hooks)))
    (ediff-setup buf-A file-A
		 buf-B file-B
		 buf-C file-C
		 startup-hooks
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		 (list (cons 'ediff-job-name job-name))
		 merge-buffer-file)))
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(declare-function diff-latest-backup-file "diff" (fn))
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;;;###autoload
(defalias 'ediff 'ediff-files)
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;;;###autoload
(defun ediff-current-file ()
  "Start ediff between current buffer and its file on disk.
This command can be used instead of `revert-buffer'.  If there is
nothing to revert then this command fails."
  (interactive)
  (unless (or revert-buffer-function
              revert-buffer-insert-file-contents-function
              (and buffer-file-number
                   (or (buffer-modified-p)
                       (not (verify-visited-file-modtime
                             (current-buffer))))))
    (error "Nothing to revert"))
  (let* ((auto-save-p (and (recent-auto-save-p)
                           buffer-auto-save-file-name
                           (file-readable-p buffer-auto-save-file-name)
                           (y-or-n-p
                            "Buffer has been auto-saved recently.  Compare with auto-save file? ")))
         (file-name (if auto-save-p
                        buffer-auto-save-file-name
                      buffer-file-name))
         (revert-buf-name (concat "FILE=" file-name))
         (revert-buf (get-buffer revert-buf-name))
         (current-major major-mode))
    (unless file-name
      (error "Buffer does not seem to be associated with any file"))
    (when revert-buf
      (kill-buffer revert-buf)
      (setq revert-buf nil))
    (setq revert-buf (get-buffer-create revert-buf-name))
    (with-current-buffer revert-buf
      (insert-file-contents file-name)
      ;; Assume same modes:
      (funcall current-major))
    (ediff-buffers revert-buf (current-buffer))))


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;;;###autoload
(defun ediff-backup (file)
  "Run Ediff on FILE and its backup file.
Uses the latest backup, if there are several numerical backups.
If this file is a backup, `ediff' it with its original."
  (interactive (list (read-file-name "Ediff (file with backup): ")))
  ;; The code is taken from `diff-backup'.
  (require 'diff)
  (let (bak ori)
    (if (backup-file-name-p file)
	(setq bak file
	      ori (file-name-sans-versions file))
      (setq bak (or (diff-latest-backup-file file)
		    (error "No backup found for %s" file))
	    ori file))
    (ediff-files bak ori)))
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;;;###autoload
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(defun ediff-buffers (buffer-A buffer-B &optional startup-hooks job-name)
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  "Run Ediff on a pair of buffers, BUFFER-A and BUFFER-B."
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  (interactive
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   (let (bf)
     (list (setq bf (read-buffer "Buffer A to compare: "
				 (ediff-other-buffer "") t))
	   (read-buffer "Buffer B to compare: "
			(progn
			  ;; realign buffers so that two visible bufs will be
			  ;; at the top
			  (save-window-excursion (other-window 1))
			  (ediff-other-buffer bf))
			t))))
  (or job-name (setq job-name 'ediff-buffers))
  (ediff-buffers-internal buffer-A buffer-B nil startup-hooks job-name))
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;;;###autoload
(defalias 'ebuffers 'ediff-buffers)

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;;;###autoload
(defun ediff-buffers3 (buffer-A buffer-B buffer-C
				 &optional startup-hooks job-name)
  "Run Ediff on three buffers, BUFFER-A, BUFFER-B, and BUFFER-C."
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  (interactive
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   (let (bf bff)
     (list (setq bf (read-buffer "Buffer A to compare: "
				 (ediff-other-buffer "") t))
	   (setq bff (read-buffer "Buffer B to compare: "
				  (progn
				    ;; realign buffers so that two visible
				    ;; bufs will be at the top
				    (save-window-excursion (other-window 1))
				    (ediff-other-buffer bf))
				  t))
	   (read-buffer "Buffer C to compare: "
				  (progn
				    ;; realign buffers so that three visible
				    ;; bufs will be at the top
				    (save-window-excursion (other-window 1))
				    (ediff-other-buffer (list bf bff)))
				  t)
	   )))
  (or job-name (setq job-name 'ediff-buffers3))
  (ediff-buffers-internal buffer-A buffer-B buffer-C startup-hooks job-name))
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;;;###autoload
(defalias 'ebuffers3 'ediff-buffers3)
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;; MERGE-BUFFER-FILE is the file to be associated with the merge buffer
(defun ediff-buffers-internal (buf-A buf-B buf-C startup-hooks job-name
				     &optional merge-buffer-file)
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  (let* ((buf-A-file-name (buffer-file-name (get-buffer buf-A)))
	 (buf-B-file-name (buffer-file-name (get-buffer buf-B)))
	 (buf-C-is-alive (ediff-buffer-live-p buf-C))
	 (buf-C-file-name (if buf-C-is-alive
			      (buffer-file-name (get-buffer buf-B))))
	 file-A file-B file-C)
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    (unwind-protect
	(progn
	  (if (not (ediff-buffer-live-p buf-A))
	      (error "Buffer %S doesn't exist" buf-A))
	  (if (not (ediff-buffer-live-p buf-B))
	      (error "Buffer %S doesn't exist" buf-B))
	  (let ((ediff-job-name job-name))
	    (if (and ediff-3way-comparison-job
		     (not buf-C-is-alive))
		(error "Buffer %S doesn't exist" buf-C)))
	  (if (stringp buf-A-file-name)
	      (setq buf-A-file-name (file-name-nondirectory buf-A-file-name)))
	  (if (stringp buf-B-file-name)
	      (setq buf-B-file-name (file-name-nondirectory buf-B-file-name)))
	  (if (stringp buf-C-file-name)
	      (setq buf-C-file-name (file-name-nondirectory buf-C-file-name)))
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	  (setq file-A (ediff-make-temp-file buf-A buf-A-file-name)
		file-B (ediff-make-temp-file buf-B buf-B-file-name))
	  (if buf-C-is-alive
	      (setq file-C (ediff-make-temp-file buf-C buf-C-file-name)))
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	  (ediff-setup (get-buffer buf-A) file-A
		       (get-buffer buf-B) file-B
		       (if buf-C-is-alive (get-buffer buf-C))
		       file-C
		       (cons `(lambda ()
				(delete-file ,file-A)
				(delete-file ,file-B)
				(if (stringp ,file-C) (delete-file ,file-C)))
			     startup-hooks)
		       (list (cons 'ediff-job-name job-name))
		       merge-buffer-file))
      (if (and (stringp file-A) (file-exists-p file-A))
	  (delete-file file-A))
      (if (and (stringp file-B) (file-exists-p file-B))
	  (delete-file file-B))
      (if (and (stringp file-C) (file-exists-p file-C))
	  (delete-file file-C)))))
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;;; Directory and file group operations

;; Get appropriate default name for directory:
;; If ediff-use-last-dir, use ediff-last-dir-A.
;; In dired mode, use the directory that is under the point (if any);
;; otherwise, use default-directory
(defun ediff-get-default-directory-name ()
  (cond (ediff-use-last-dir ediff-last-dir-A)
	((eq major-mode 'dired-mode)
	 (let ((f (dired-get-filename nil 'noerror)))
	   (if (and (stringp f) (file-directory-p f))
	       f
	     default-directory)))
	(t default-directory)))


;;;###autoload
(defun ediff-directories (dir1 dir2 regexp)
  "Run Ediff on a pair of directories, DIR1 and DIR2, comparing files that have
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the same name in both.  The third argument, REGEXP, is nil or a regular
expression; only file names that match the regexp are considered."
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  (interactive
   (let ((dir-A (ediff-get-default-directory-name))
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	 (default-regexp (eval ediff-default-filtering-regexp))
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	 f)
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     (list (setq f (read-directory-name
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		    "Directory A to compare: " dir-A nil 'must-match))
	   (read-directory-name "Directory B to compare: "
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			   (if ediff-use-last-dir
			       ediff-last-dir-B
			     (ediff-strip-last-dir f))
			   nil 'must-match)
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	   (read-string
	    (if (stringp default-regexp)
		(format "Filter through regular expression (default %s): "
			 default-regexp)
	      "Filter through regular expression: ")
	    nil
	    'ediff-filtering-regexp-history
	    (eval ediff-default-filtering-regexp))
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	   )))
  (ediff-directories-internal
   dir1 dir2 nil regexp 'ediff-files 'ediff-directories
   ))

;;;###autoload
(defalias 'edirs 'ediff-directories)


;;;###autoload
(defun ediff-directory-revisions (dir1 regexp)
  "Run Ediff on a directory, DIR1, comparing its files with their revisions.
The second argument, REGEXP, is a regular expression that filters the file
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names.  Only the files that are under revision control are taken into account."
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  (interactive
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   (let ((dir-A (ediff-get-default-directory-name))
	 (default-regexp (eval ediff-default-filtering-regexp))
	 )
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     (list (read-directory-name
	    "Directory to compare with revision:" dir-A nil 'must-match)
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	   (read-string
	    (if (stringp default-regexp)
		(format "Filter through regular expression (default %s): "
			 default-regexp)
	      "Filter through regular expression: ")
	    nil
	    'ediff-filtering-regexp-history
	    (eval ediff-default-filtering-regexp))
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	   )))
  (ediff-directory-revisions-internal
   dir1 regexp 'ediff-revision 'ediff-directory-revisions
   ))

;;;###autoload
(defalias 'edir-revisions 'ediff-directory-revisions)


;;;###autoload
(defun ediff-directories3 (dir1 dir2 dir3 regexp)
  "Run Ediff on three directories, DIR1, DIR2, and DIR3, comparing files that
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have the same name in all three.  The last argument, REGEXP, is nil or a
regular expression; only file names that match the regexp are considered."

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  (interactive
   (let ((dir-A (ediff-get-default-directory-name))
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	 (default-regexp (eval ediff-default-filtering-regexp))
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	 f)
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     (list (setq f (read-directory-name "Directory A to compare:" dir-A nil))
	   (setq f (read-directory-name "Directory B to compare:"
				   (if ediff-use-last-dir
				       ediff-last-dir-B
				     (ediff-strip-last-dir f))
				   nil 'must-match))
	   (read-directory-name "Directory C to compare:"
			   (if ediff-use-last-dir
			       ediff-last-dir-C
			     (ediff-strip-last-dir f))
			   nil 'must-match)
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	   (read-string
	    (if (stringp default-regexp)
		(format "Filter through regular expression (default %s): "
			 default-regexp)
	      "Filter through regular expression: ")
	    nil
	    'ediff-filtering-regexp-history
	    (eval ediff-default-filtering-regexp))
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	   )))
  (ediff-directories-internal
   dir1 dir2 dir3 regexp 'ediff-files3 'ediff-directories3
   ))

;;;###autoload
(defalias 'edirs3 'ediff-directories3)

;;;###autoload
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(defun ediff-merge-directories (dir1 dir2 regexp &optional merge-autostore-dir)
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  "Run Ediff on a pair of directories, DIR1 and DIR2, merging files that have
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the same name in both.  The third argument, REGEXP, is nil or a regular
expression; only file names that match the regexp are considered."
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  (interactive
   (let ((dir-A (ediff-get-default-directory-name))
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	 (default-regexp (eval ediff-default-filtering-regexp))
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	 f)
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     (list (setq f (read-directory-name "Directory A to merge:"
					dir-A nil 'must-match))
	   (read-directory-name "Directory B to merge:"
			   (if ediff-use-last-dir
			       ediff-last-dir-B
			     (ediff-strip-last-dir f))
			   nil 'must-match)
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	   (read-string
	    (if (stringp default-regexp)
		(format "Filter through regular expression (default %s): "
			 default-regexp)
	      "Filter through regular expression: ")
	    nil
	    'ediff-filtering-regexp-history
	    (eval ediff-default-filtering-regexp))
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	   )))
  (ediff-directories-internal
   dir1 dir2 nil regexp 'ediff-merge-files 'ediff-merge-directories
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   nil merge-autostore-dir
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   ))

;;;###autoload
(defalias 'edirs-merge 'ediff-merge-directories)

;;;###autoload
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(defun ediff-merge-directories-with-ancestor (dir1 dir2 ancestor-dir regexp
						   &optional
						   merge-autostore-dir)
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  "Merge files in directories DIR1 and DIR2 using files in ANCESTOR-DIR as ancestors.
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Ediff merges files that have identical names in DIR1, DIR2.  If a pair of files
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in DIR1 and DIR2 doesn't have an ancestor in ANCESTOR-DIR, Ediff will merge
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without ancestor.  The fourth argument, REGEXP, is nil or a regular expression;
only file names that match the regexp are considered."
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  (interactive
   (let ((dir-A (ediff-get-default-directory-name))
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	 (default-regexp (eval ediff-default-filtering-regexp))
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	 f)
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     (list (setq f (read-directory-name "Directory A to merge:" dir-A nil))
	   (setq f (read-directory-name "Directory B to merge:"
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				 (if ediff-use-last-dir
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				     ediff-last-dir-B
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				   (ediff-strip-last-dir f))
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				 nil 'must-match))
	   (read-directory-name "Ancestor directory:"
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				 (if ediff-use-last-dir
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				     ediff-last-dir-C
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				   (ediff-strip-last-dir f))
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				 nil 'must-match)
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	   (read-string
	    (if (stringp default-regexp)
		(format "Filter through regular expression (default %s): "
			 default-regexp)
	      "Filter through regular expression: ")
	    nil
	    'ediff-filtering-regexp-history
	    (eval ediff-default-filtering-regexp))
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	   )))
  (ediff-directories-internal
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   dir1 dir2 ancestor-dir regexp
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   'ediff-merge-files-with-ancestor 'ediff-merge-directories-with-ancestor
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   nil merge-autostore-dir
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   ))

;;;###autoload
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(defun ediff-merge-directory-revisions (dir1 regexp
					     &optional merge-autostore-dir)
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  "Run Ediff on a directory, DIR1, merging its files with their revisions.
The second argument, REGEXP, is a regular expression that filters the file
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names.  Only the files that are under revision control are taken into account."
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  (interactive
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   (let ((dir-A (ediff-get-default-directory-name))
	 (default-regexp (eval ediff-default-filtering-regexp))
	 )
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     (list (read-directory-name
	    "Directory to merge with revisions:" dir-A nil 'must-match)
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	   (read-string
	    (if (stringp default-regexp)
		(format "Filter through regular expression (default %s): "
			 default-regexp)
	      "Filter through regular expression: ")
	    nil
	    'ediff-filtering-regexp-history
	    (eval ediff-default-filtering-regexp))
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	   )))
  (ediff-directory-revisions-internal
   dir1 regexp 'ediff-merge-revisions 'ediff-merge-directory-revisions
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   nil merge-autostore-dir
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   ))

;;;###autoload
(defalias 'edir-merge-revisions 'ediff-merge-directory-revisions)

;;;###autoload
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(defun ediff-merge-directory-revisions-with-ancestor (dir1 regexp
							   &optional
							   merge-autostore-dir)
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  "Run Ediff on a directory, DIR1, merging its files with their revisions and ancestors.
The second argument, REGEXP, is a regular expression that filters the file
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names.  Only the files that are under revision control are taken into account."
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  (interactive
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   (let ((dir-A (ediff-get-default-directory-name))
	 (default-regexp (eval ediff-default-filtering-regexp))
	 )
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     (list (read-directory-name
	    "Directory to merge with revisions and ancestors:"
	    dir-A nil 'must-match)
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	   (read-string
	    (if (stringp default-regexp)
		(format "Filter through regular expression (default %s): "
			 default-regexp)
	      "Filter through regular expression: ")
	    nil
	    'ediff-filtering-regexp-history
	    (eval ediff-default-filtering-regexp))
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	   )))
  (ediff-directory-revisions-internal
   dir1 regexp 'ediff-merge-revisions-with-ancestor
   'ediff-merge-directory-revisions-with-ancestor
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   nil merge-autostore-dir
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   ))

;;;###autoload
(defalias
  'edir-merge-revisions-with-ancestor
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  'ediff-merge-directory-revisions-with-ancestor)
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;;;###autoload
(defalias 'edirs-merge-with-ancestor 'ediff-merge-directories-with-ancestor)

;; Run ediff-action (ediff-files, ediff-merge, ediff-merge-with-ancestors)
;; on a pair of directories (three directories, in case of ancestor).
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;; The third argument, REGEXP, is nil or a regular expression;
;; only file names that match the regexp are considered.
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;; JOBNAME is the symbol indicating the meta-job to be performed.
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;; MERGE-AUTOSTORE-DIR is the directory in which to store merged files.
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(defun ediff-directories-internal (dir1 dir2 dir3 regexp action jobname
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					&optional startup-hooks
					merge-autostore-dir)
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  (if (stringp dir3)
      (setq dir3 (if (file-directory-p dir3) dir3 (file-name-directory dir3))))

  (cond ((string= dir1 dir2)
	 (error "Directories A and B are the same: %s" dir1))
	((and (eq jobname 'ediff-directories3)
	      (string= dir1 dir3))
	 (error "Directories A and C are the same: %s" dir1))
	((and (eq jobname 'ediff-directories3)
	      (string= dir2 dir3))
	 (error "Directories B and C are the same: %s" dir1)))

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  (if merge-autostore-dir
      (or (stringp merge-autostore-dir)
	  (error "%s: Directory for storing merged files must be a string"
		 jobname)))
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  (let (;; dir-diff-struct is of the form (common-list diff-list)
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	;; It is a structure where ediff-intersect-directories returns
	;; commonalities and differences among directories
	dir-diff-struct
	meta-buf)
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    (if (and ediff-autostore-merges
	     (ediff-merge-metajob jobname)
	     (not merge-autostore-dir))
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	(setq merge-autostore-dir
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	      (read-directory-name "Save merged files in directory: "
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			      (if ediff-use-last-dir
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					ediff-last-merge-autostore-dir
				      (ediff-strip-last-dir dir1))
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			      nil
			      'must-match)))
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    ;; verify we are not merging into an orig directory
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    (if merge-autostore-dir
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	(cond ((and (stringp dir1) (string= merge-autostore-dir dir1))
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	       (or (y-or-n-p
		    "Directory for saving merged files = Directory A.  Sure? ")
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		   (error "Directory merge aborted")))
	      ((and (stringp dir2) (string= merge-autostore-dir dir2))
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	       (or (y-or-n-p
		    "Directory for saving merged files = Directory B.  Sure? ")
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		   (error "Directory merge aborted")))
	      ((and (stringp dir3) (string= merge-autostore-dir dir3))
	       (or (y-or-n-p
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		    "Directory for saving merged files = Ancestor Directory.  Sure? ")
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		   (error "Directory merge aborted")))))
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    (setq dir-diff-struct (ediff-intersect-directories
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			   jobname
			   regexp dir1 dir2 dir3 merge-autostore-dir))
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    (setq startup-hooks
	  ;; this sets various vars in the meta buffer inside
	  ;; ediff-prepare-meta-buffer
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	  (cons `(lambda ()
		   ;; tell what to do if the user clicks on a session record
		   (setq ediff-session-action-function (quote ,action))
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		   ;; set ediff-dir-difference-list
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		   (setq ediff-dir-difference-list
			 (cdr (quote ,dir-diff-struct))))
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		startup-hooks))
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    (setq meta-buf (ediff-prepare-meta-buffer
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		    'ediff-filegroup-action
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		    (car dir-diff-struct)
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		    "*Ediff Session Group Panel"
		    'ediff-redraw-directory-group-buffer
		    jobname
		    startup-hooks))
    (ediff-show-meta-buffer meta-buf)
    ))

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;; MERGE-AUTOSTORE-DIR can be given to tell ediff where to store the merged
;; files
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(defun ediff-directory-revisions-internal (dir1 regexp action jobname
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						&optional startup-hooks
						merge-autostore-dir)
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  (setq dir1 (if (file-directory-p dir1) dir1 (file-name-directory dir1)))
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  (if merge-autostore-dir
      (or (stringp merge-autostore-dir)
	  (error "%S: Directory for storing merged files must be a string"
		 jobname)))
  (let (file-list meta-buf)
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    (if (and ediff-autostore-merges
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	     (ediff-merge-metajob jobname)
	     (not merge-autostore-dir))
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	(setq merge-autostore-dir
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	      (read-directory-name "Save merged files in directory: "
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			      (if ediff-use-last-dir
				  ediff-last-merge-autostore-dir
				(ediff-strip-last-dir dir1))
			      nil
			      'must-match)))
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    ;; verify merge-autostore-dir != dir1
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    (if (and merge-autostore-dir
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	     (stringp dir1)
	     (string= merge-autostore-dir dir1))
	(or (y-or-n-p
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	     "Directory for saving merged file = directory A.  Sure? ")
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	    (error "Merge of directory revisions aborted")))
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    (setq file-list
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	  (ediff-get-directory-files-under-revision
	   jobname regexp dir1 merge-autostore-dir))
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    (setq startup-hooks
	  ;; this sets various vars in the meta buffer inside
	  ;; ediff-prepare-meta-buffer
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	  (cons `(lambda ()
		   ;; tell what to do if the user clicks on a session record
		   (setq ediff-session-action-function (quote ,action)))
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		startup-hooks))
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    (setq meta-buf (ediff-prepare-meta-buffer
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		    'ediff-filegroup-action
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		    file-list
		    "*Ediff Session Group Panel"
		    'ediff-redraw-directory-group-buffer
		    jobname
		    startup-hooks))
    (ediff-show-meta-buffer meta-buf)
    ))
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;;; Compare regions and windows

;;;###autoload
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(defun ediff-windows-wordwise (dumb-mode &optional wind-A wind-B startup-hooks)
  "Compare WIND-A and WIND-B, which are selected by clicking, wordwise.
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With prefix argument, DUMB-MODE, or on a non-windowing display, works as
follows:
If WIND-A is nil, use selected window.
If WIND-B is nil, use window next to WIND-A."
  (interactive "P")
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  (ediff-windows dumb-mode wind-A wind-B
		 startup-hooks 'ediff-windows-wordwise 'word-mode))
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;;;###autoload
(defun ediff-windows-linewise (dumb-mode &optional wind-A wind-B startup-hooks)
  "Compare WIND-A and WIND-B, which are selected by clicking, linewise.
With prefix argument, DUMB-MODE, or on a non-windowing display, works as
follows:
If WIND-A is nil, use selected window.
If WIND-B is nil, use window next to WIND-A."
  (interactive "P")
  (ediff-windows dumb-mode wind-A wind-B
		 startup-hooks 'ediff-windows-linewise nil))
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;; Compare WIND-A and WIND-B, which are selected by clicking.
;; With prefix argument, DUMB-MODE, or on a non-windowing display,
;; works as follows:
;; If WIND-A is nil, use selected window.
;; If WIND-B is nil, use window next to WIND-A.
(defun ediff-windows (dumb-mode wind-A wind-B startup-hooks job-name word-mode)
  (if (or dumb-mode (not (ediff-window-display-p)))
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      (setq wind-A (ediff-get-next-window wind-A nil)
	    wind-B (ediff-get-next-window wind-B wind-A))
    (setq wind-A (ediff-get-window-by-clicking wind-A nil 1)
	  wind-B (ediff-get-window-by-clicking wind-B wind-A 2)))
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  (let ((buffer-A (window-buffer wind-A))
	(buffer-B (window-buffer wind-B))
	beg-A end-A beg-B end-B)
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    (save-excursion
      (save-window-excursion
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	(sit-for 0) ; sync before using window-start/end -- a precaution
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	(select-window wind-A)
	(setq beg-A (window-start)
	      end-A (window-end))
	(select-window wind-B)
	(setq beg-B (window-start)
	      end-B (window-end))))
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    (setq buffer-A
	  (ediff-clone-buffer-for-window-comparison
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	   buffer-A wind-A "-Window.A-")
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	  buffer-B
	  (ediff-clone-buffer-for-window-comparison
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	   buffer-B wind-B "-Window.B-"))
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    (ediff-regions-internal
     buffer-A beg-A end-A buffer-B beg-B end-B
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     startup-hooks job-name word-mode nil)))
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;;;###autoload
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(defun ediff-regions-wordwise (buffer-A buffer-B &optional startup-hooks)
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  "Run Ediff on a pair of regions in specified buffers.
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Regions \(i.e., point and mark\) can be set in advance or marked interactively.
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This function is effective only for relatively small regions, up to 200
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lines.  For large regions, use `ediff-regions-linewise'."
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  (interactive
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   (let (bf)
     (list (setq bf (read-buffer "Region's A buffer: "
				 (ediff-other-buffer "") t))
	   (read-buffer "Region's B buffer: "
			(progn
			  ;; realign buffers so that two visible bufs will be
			  ;; at the top
			  (save-window-excursion (other-window 1))
			  (ediff-other-buffer bf))
			t))))
  (if (not (ediff-buffer-live-p buffer-A))
      (error "Buffer %S doesn't exist" buffer-A))
  (if (not (ediff-buffer-live-p buffer-B))
      (error "Buffer %S doesn't exist" buffer-B))