stgit.el: Annotate stgit-capture-output macro for edebug

[stgit] / contrib / stgit.el

;; stgit.el: An emacs mode for StGit
;;
;; Copyright (C) 2007 David Kågedal <davidk@lysator.liu.se>
;;
;; To install: put this file on the load-path and place the following
;; in your .emacs file:
;;
;;    (require 'stgit)
;;
;; To start: `M-x stgit'

(when (< emacs-major-version 22)
  (error "Emacs older than 22 is not supported by stgit.el"))

(require 'git nil t)
(require 'cl)
(require 'ewoc)
(require 'easymenu)
(require 'format-spec)

(defun stgit-set-default (symbol value)
  "Set default value of SYMBOL to VALUE using `set-default' and
reload all StGit buffers."
  (set-default symbol value)
  (dolist (buf (buffer-list))
    (with-current-buffer buf
      (when (eq major-mode 'stgit-mode)
        (stgit-reload)))))

(defgroup stgit nil
  "A user interface for the StGit patch maintenance tool."
  :group 'tools
  :link '(function-link stgit)
  :link '(url-link "http://www.procode.org/stgit/"))

(defcustom stgit-abbreviate-copies-and-renames t
  "If non-nil, abbreviate copies and renames as \"dir/{old -> new}/file\"
instead of \"dir/old/file -> dir/new/file\"."
  :type 'boolean
  :group 'stgit
  :set 'stgit-set-default)

(defcustom stgit-default-show-worktree t
  "Set to non-nil to by default show the working tree in a new stgit buffer.

Use \\<stgit-mode-map>\\[stgit-toggle-worktree] to toggle the this setting in an already-started StGit buffer."
  :type 'boolean
  :group 'stgit
  :link '(variable-link stgit-show-worktree))

(defcustom stgit-find-copies-harder nil
  "Try harder to find copied files when listing patches.

When not nil, runs git diff-tree with the --find-copies-harder
flag, which reduces performance."
  :type 'boolean
  :group 'stgit
  :set 'stgit-set-default)

(defcustom stgit-show-worktree-mode 'center
  "This variable controls where the \"Index\" and \"Work tree\"
will be shown on in the buffer.

It can be set to 'top (above all patches), 'center (show between
applied and unapplied patches), and 'bottom (below all patches)."
  :type '(radio (const :tag "above all patches (top)" top)
                (const :tag "between applied and unapplied patches (center)"
                       center)
                (const :tag "below all patches (bottom)" bottom))
  :group 'stgit
  :link '(variable-link stgit-show-worktree)
  :set 'stgit-set-default)

(defcustom stgit-patch-line-format "%s%m%-30n %e%d"
  "The format string used to format patch lines.
The format string is passed to `format-spec' and the following
format characters are recognized:

  %s - A '+', '-', '>' or space, depending on whether the patch is
       applied, unapplied, top, or something else.

  %m - An asterisk if the patch is marked, and a space otherwise.

  %n - The patch name.

  %e - The string \"(empty) \" if the patch is empty.

  %d - The short patch description.

  %D - The short patch description, or the patch name.

When `stgit-show-patch-names' is non-nil, the `stgit-noname-patch-line-format'
variable is used instead."
  :type 'string
  :group 'stgit
  :set 'stgit-set-default)

(defcustom stgit-noname-patch-line-format "%s%m%e%D"
  "The alternate format string used to format patch lines.
It has the same semantics as `stgit-patch-line-format', and the
display can be toggled between the two formats using
\\<stgit-mode-map>>\\[stgit-toggle-patch-names].

The alternate form is used when the patch name is hidden."
  :type 'string
  :group 'stgit
  :set 'stgit-set-default)

(defcustom stgit-default-show-patch-names t
  "If non-nil, default to showing patch names in a new stgit buffer.

Use \\<stgit-mode-map>\\[stgit-toggle-patch-names] to toggle the
this setting in an already-started StGit buffer."
  :type 'boolean
  :group 'stgit
  :link '(variable-link stgit-show-patch-names))

(defcustom stgit-file-line-format "    %-11s %-2m %n   %c"
  "The format string used to format file lines.
The format string is passed to `format-spec' and the following
format characters are recognized:

  %s - A string describing the status of the file.

  %m - Mode change information

  %n - The file name.

  %c - A description of file changes."
  :type 'string
  :group 'stgit
  :set 'stgit-set-default)

(defface stgit-branch-name-face
  '((t :inherit bold))
  "The face used for the StGit branch name"
  :group 'stgit)

(defface stgit-top-patch-face
  '((((background dark)) (:weight bold :foreground "yellow"))
    (((background light)) (:weight bold :foreground "purple"))
    (t (:weight bold)))
  "The face used for the top patch names"
  :group 'stgit)

(defface stgit-applied-patch-face
  '((((background dark)) (:foreground "light yellow"))
    (((background light)) (:foreground "purple"))
    (t ()))
  "The face used for applied patch names"
  :group 'stgit)

(defface stgit-unapplied-patch-face
  '((((background dark)) (:foreground "gray80"))
    (((background light)) (:foreground "orchid"))
    (t ()))
  "The face used for unapplied patch names"
  :group 'stgit)

(defface stgit-description-face
  '((((background dark)) (:foreground "tan"))
    (((background light)) (:foreground "dark red")))
  "The face used for StGit descriptions"
  :group 'stgit)

(defface stgit-index-work-tree-title-face
  '((((supports :slant italic)) :slant italic)
    (t :inherit bold))
  "StGit mode face used for the \"Index\" and \"Work tree\" titles"
  :group 'stgit)

(defface stgit-unmerged-file-face
  '((((class color) (background light)) (:foreground "red" :bold t))
    (((class color) (background dark)) (:foreground "red" :bold t)))
  "StGit mode face used for unmerged file status"
  :group 'stgit)

(defface stgit-unknown-file-face
  '((((class color) (background light)) (:foreground "goldenrod" :bold t))
    (((class color) (background dark)) (:foreground "goldenrod" :bold t)))
  "StGit mode face used for unknown file status"
  :group 'stgit)

(defface stgit-ignored-file-face
  '((((class color) (background light)) (:foreground "grey60"))
    (((class color) (background dark)) (:foreground "grey40")))
  "StGit mode face used for ignored files")

(defface stgit-file-permission-face
  '((((class color) (background light)) (:foreground "green" :bold t))
    (((class color) (background dark)) (:foreground "green" :bold t)))
  "StGit mode face used for permission changes."
  :group 'stgit)

(defface stgit-modified-file-face
  '((((class color) (background light)) (:foreground "purple"))
    (((class color) (background dark)) (:foreground "salmon")))
  "StGit mode face used for modified file status"
  :group 'stgit)

(defun stgit (dir)
  "Manage StGit patches for the tree in DIR.

See `stgit-mode' for commands available."
  (interactive "DDirectory: \n")
  (switch-to-stgit-buffer (git-get-top-dir dir))
  (stgit-reload))

(defun stgit-assert-mode ()
  "Signal an error if not in an StGit buffer."
  (assert (derived-mode-p 'stgit-mode) nil "Not an StGit buffer"))

(unless (fboundp 'git-get-top-dir)
  (defun git-get-top-dir (dir)
    "Retrieve the top-level directory of a git tree."
    (let ((cdup (with-output-to-string
                  (with-current-buffer standard-output
                    (cd dir)
                    (unless (eq 0 (call-process "git" nil t nil
                                                "rev-parse" "--show-cdup"))
                      (error "Cannot find top-level git tree for %s" dir))))))
      (expand-file-name (concat (file-name-as-directory dir)
                                (car (split-string cdup "\n")))))))

(defun stgit-refresh-git-status (&optional dir)
  "If it exists, refresh the `git-status' buffer belonging to
directory DIR or `default-directory'"
  (when (and (fboundp 'git-find-status-buffer)
             (fboundp 'git-refresh-status))
    (let* ((top-dir (git-get-top-dir (or dir default-directory)))
           (git-status-buffer (and top-dir (git-find-status-buffer top-dir))))
      (when git-status-buffer
        (with-current-buffer git-status-buffer
          (git-refresh-status))))))

(defun stgit-find-buffer (dir)
  "Return the buffer displaying StGit patches for DIR, or nil if none."
  (setq dir (file-name-as-directory dir))
  (let ((buffers (buffer-list)))
    (while (and buffers
                (not (with-current-buffer (car buffers)
                       (and (eq major-mode 'stgit-mode)
                            (string= default-directory dir)))))
      (setq buffers (cdr buffers)))
    (and buffers (car buffers))))

(defun switch-to-stgit-buffer (dir)
  "Switch to a (possibly new) buffer displaying StGit patches for DIR."
  (setq dir (file-name-as-directory dir))
  (let ((buffer (stgit-find-buffer dir)))
    (switch-to-buffer (or buffer
                          (create-stgit-buffer dir)))))

(defstruct (stgit-patch
            (:conc-name stgit-patch->))
  status name desc empty files-ewoc)

(defun stgit-patch-display-name (patch)
  (let ((name (stgit-patch->name patch)))
    (case name
      (:index "Index")
      (:work "Work Tree")
      (t (symbol-name name)))))

(defun stgit-insert-without-trailing-whitespace (text)
  "Insert TEXT in buffer using `insert', without trailing whitespace.
A newline is appended."
  (unless (string-match "\\(.*?\\) *$" text)
    (error))
  (insert (match-string 1 text) ?\n))

(defun stgit-patch-pp (patch)
  (let* ((status (stgit-patch->status patch))
         (start (point))
         (name (stgit-patch->name patch))
         (face (cdr (assq status stgit-patch-status-face-alist)))
         (fmt (if stgit-show-patch-names
                  stgit-patch-line-format
                stgit-noname-patch-line-format))
         (spec (format-spec-make
                ?s (case status
                     ('applied "+")
                     ('top ">")
                     ('unapplied "-")
                     (t " "))
                ?m (if (memq name stgit-marked-patches)
                       "*" " ")
                ?n (propertize (stgit-patch-display-name patch)
                               'face face
                               'syntax-table (string-to-syntax "w"))
                ?e (if (stgit-patch->empty patch) "(empty) " "")
                ?d (propertize (or (stgit-patch->desc patch) "")
                               'face 'stgit-description-face)
                ?D (propertize (let ((desc (stgit-patch->desc patch)))
                                 (if (zerop (length desc))
                                   (stgit-patch-display-name patch)
                                   desc))
                               'face face)))
         (text (format-spec fmt spec)))

    (stgit-insert-without-trailing-whitespace text)
    (put-text-property start (point) 'entry-type 'patch)
    (when (memq name stgit-expanded-patches)
      (stgit-insert-patch-files patch))
    (put-text-property start (point) 'patch-data patch)))

(defun create-stgit-buffer (dir)
  "Create a buffer for showing StGit patches.
Argument DIR is the repository path."
  (let ((buf (create-file-buffer (concat dir "*stgit*")))
        (inhibit-read-only t))
    (with-current-buffer buf
      (setq default-directory dir)
      (stgit-mode)
      (set (make-local-variable 'stgit-ewoc)
           (ewoc-create #'stgit-patch-pp "Branch:\n\n" "--\n" t))
      (setq buffer-read-only t))
    buf))

(def-edebug-spec stgit-capture-output
  (form body))
(defmacro stgit-capture-output (name &rest body)
  "Capture StGit output and, if there was any output, show it in a window
at the end.
Returns nil if there was no output."
  (declare (debug ([&or stringp null] body))
           (indent 1))
  `(let ((output-buf (get-buffer-create ,(or name "*StGit output*")))
         (stgit-dir default-directory)
         (inhibit-read-only t))
     (with-current-buffer output-buf
       (buffer-disable-undo)
       (erase-buffer)
       (setq default-directory stgit-dir)
       (setq buffer-read-only t))
     (let ((standard-output output-buf))
       ,@body)
     (with-current-buffer output-buf
       (set-buffer-modified-p nil)
       (setq buffer-read-only t)
       (if (< (point-min) (point-max))
           (display-buffer output-buf t)))))

(defun stgit-make-run-args (args)
  "Return a copy of ARGS with its elements converted to strings."
  (mapcar (lambda (x)
            ;; don't use (format "%s" ...) to limit type errors
            (cond ((stringp x) x)
                  ((integerp x) (number-to-string x))
                  ((symbolp x) (symbol-name x))
                  (t
                   (error "Bad element in stgit-make-run-args args: %S" x))))
          args))

(defun stgit-run-silent (&rest args)
  (setq args (stgit-make-run-args args))
  (apply 'call-process "stg" nil standard-output nil args))

(defun stgit-run (&rest args)
  (setq args (stgit-make-run-args args))
  (let ((msgcmd (mapconcat #'identity args " ")))
    (message "Running stg %s..." msgcmd)
    (apply 'call-process "stg" nil standard-output nil args)
    (message "Running stg %s...done" msgcmd)))

(defun stgit-run-git (&rest args)
  (setq args (stgit-make-run-args args))
  (let ((msgcmd (mapconcat #'identity args " ")))
    (message "Running git %s..." msgcmd)
    (apply 'call-process "git" nil standard-output nil args)
    (message "Running git %s...done" msgcmd)))

(defun stgit-run-git-silent (&rest args)
  (setq args (stgit-make-run-args args))
  (apply 'call-process "git" nil standard-output nil args))

(defun stgit-index-empty-p ()
  "Returns non-nil if the index contains no changes from HEAD."
  (zerop (stgit-run-git-silent "diff-index" "--cached" "--quiet" "HEAD")))

(defun stgit-work-tree-empty-p ()
  "Returns non-nil if the work tree contains no changes from index."
  (zerop (stgit-run-git-silent "diff-files" "--quiet")))

(defvar stgit-index-node)
(defvar stgit-worktree-node)

(defconst stgit-allowed-branch-name-re
  ;; Disallow control characters, space, del, and "/:@^{}~" in
  ;; "/"-separated parts; parts may not start with a period (.)
  "^[^\0- ./:@^{}~\177][^\0- /:@^{}~\177]*\
\\(/[^\0- ./:@^{}~\177][^\0- /:@^{}~\177]*\\)*$"
  "Regular expression that (new) branch names must match.")

(defun stgit-refresh-index ()
  (when stgit-index-node
    (ewoc-invalidate (car stgit-index-node) (cdr stgit-index-node))))

(defun stgit-refresh-worktree ()
  (when stgit-worktree-node
    (ewoc-invalidate (car stgit-worktree-node) (cdr stgit-worktree-node))))

(defun stgit-run-series-insert-index (ewoc)
  (setq index-node    (cons ewoc (ewoc-enter-last ewoc
                                                  (make-stgit-patch
                                                   :status 'index
                                                   :name :index
                                                   :desc nil
                                                   :empty nil)))
        worktree-node (cons ewoc (ewoc-enter-last ewoc
                                                  (make-stgit-patch
                                                   :status 'work
                                                   :name :work
                                                   :desc nil
                                                   :empty nil)))))

(defun stgit-run-series (ewoc)
  (setq stgit-index-node nil
        stgit-worktree-node nil)
  (let ((inserted-index (not stgit-show-worktree))
        index-node
        worktree-node
        all-patchsyms)
    (with-temp-buffer
      (let* ((standard-output (current-buffer))
             (exit-status (stgit-run-silent "series"
                                            "--description" "--empty")))
        (goto-char (point-min))
        (if (not (zerop exit-status))
            (cond ((looking-at "stg series: \\(.*\\)")
                   (setq inserted-index t)
                   (ewoc-set-hf ewoc (car (ewoc-get-hf ewoc))
                                (substitute-command-keys
                                 "-- not initialized; run \\[stgit-init]")))
                  ((looking-at ".*")
                   (error "Error running stg: %s"
                          (match-string 0))))
          (while (not (eobp))
            (unless (looking-at
                     "\\([0 ]\\)\\([>+-]\\)\\( \\)\\([^ ]+\\) *[|#] \\(.*\\)")
              (error "Syntax error in output from stg series"))
            (let* ((state-str (match-string 2))
                   (state (cond ((string= state-str ">") 'top)
                                ((string= state-str "+") 'applied)
                                ((string= state-str "-") 'unapplied)))
                   (name (intern (match-string 4)))
                   (desc (match-string 5))
                   (empty (string= (match-string 1) "0")))
              (unless inserted-index
                (when (or (eq stgit-show-worktree-mode 'top)
                          (and (eq stgit-show-worktree-mode 'center)
                               (eq state 'unapplied)))
                  (setq inserted-index t)
                  (stgit-run-series-insert-index ewoc)))
              (setq all-patchsyms (cons name all-patchsyms))
              (ewoc-enter-last ewoc
                               (make-stgit-patch
                                :status state
                                :name   name
                                :desc   desc
                                :empty  empty)))
            (forward-line 1))))
      (unless inserted-index
        (stgit-run-series-insert-index ewoc)))
    (setq stgit-index-node    index-node
          stgit-worktree-node worktree-node
          stgit-marked-patches (intersection stgit-marked-patches
                                             all-patchsyms))))

(defun stgit-current-branch ()
  "Return the name of the current branch."
  (substring (with-output-to-string
               (stgit-run-silent "branch"))
             0 -1))

(defun stgit-reload ()
  "Update the contents of the StGit buffer."
  (interactive)
  (stgit-assert-mode)
  (let ((inhibit-read-only t)
        (curline (line-number-at-pos))
        (curpatch (stgit-patch-name-at-point))
        (curfile (stgit-patched-file-at-point)))
    (ewoc-filter stgit-ewoc #'(lambda (x) nil))
    (ewoc-set-hf stgit-ewoc
                 (concat "Branch: "
                         (propertize (stgit-current-branch)
                                     'face 'stgit-branch-name-face)
                         "\n\n")
                 (if stgit-show-worktree
                     "--"
                   (propertize
                    (substitute-command-keys "--\n\"\\[stgit-toggle-worktree]\"\
 shows the working tree\n")
                    'face 'stgit-description-face)))
    (stgit-run-series stgit-ewoc)
    (if curpatch
        (stgit-goto-patch curpatch (and curfile (stgit-file->file curfile)))
      (goto-line curline)))
  (stgit-refresh-git-status))

(defconst stgit-file-status-code-strings
  (mapcar (lambda (arg)
            (cons (car arg)
                  (propertize (cadr arg) 'face (car (cddr arg)))))
          '((add         "Added"       stgit-modified-file-face)
            (copy        "Copied"      stgit-modified-file-face)
            (delete      "Deleted"     stgit-modified-file-face)
            (modify      "Modified"    stgit-modified-file-face)
            (rename      "Renamed"     stgit-modified-file-face)
            (mode-change "Mode change" stgit-modified-file-face)
            (unmerged    "Unmerged"    stgit-unmerged-file-face)
            (unknown     "Unknown"     stgit-unknown-file-face)
            (ignore      "Ignored"     stgit-ignored-file-face)))
  "Alist of code symbols to description strings")

(defconst stgit-patch-status-face-alist
  '((applied   . stgit-applied-patch-face)
    (top       . stgit-top-patch-face)
    (unapplied . stgit-unapplied-patch-face)
    (index     . stgit-index-work-tree-title-face)
    (work      . stgit-index-work-tree-title-face))
  "Alist of face to use for a given patch status")

(defun stgit-file-status-code-as-string (file)
  "Return stgit status code for FILE as a string"
  (let* ((code (assq (stgit-file->status file)
                     stgit-file-status-code-strings))
         (score (stgit-file->cr-score file)))
    (when code
      (if (and score (/= score 100))
          (format "%s %s" (cdr code)
                  (propertize (format "%d%%" score)
                              'face 'stgit-description-face))
        (cdr code)))))

(defun stgit-file-status-code (str &optional score)
  "Return stgit status code from git status string"
  (let ((code (assoc str '(("A" . add)
                           ("C" . copy)
                           ("D" . delete)
                           ("I" . ignore)
                           ("M" . modify)
                           ("R" . rename)
                           ("T" . mode-change)
                           ("U" . unmerged)
                           ("X" . unknown)))))
    (setq code (if code (cdr code) 'unknown))
    (when (stringp score)
      (if (> (length score) 0)
          (setq score (string-to-number score))
        (setq score nil)))
    (if score (cons code score) code)))

(defconst stgit-file-type-strings
  '((#o100 . "file")
    (#o120 . "symlink")
    (#o160 . "subproject"))
  "Alist of names of file types")

(defun stgit-file-type-string (type)
  "Return string describing file type TYPE (the high bits of file permission).
Cf. `stgit-file-type-strings' and `stgit-file-type-change-string'."
  (let ((type-str (assoc type stgit-file-type-strings)))
    (or (and type-str (cdr type-str))
        (format "unknown type %o" type))))

(defun stgit-file-type-change-string (old-perm new-perm)
  "Return string describing file type change from OLD-PERM to NEW-PERM.
Cf. `stgit-file-type-string'."
  (let ((old-type (lsh old-perm -9))
        (new-type (lsh new-perm -9)))
    (cond ((= old-type new-type) "")
          ((zerop new-type) "")
          ((zerop old-type)
           (if (= new-type #o100)
               ""
             (format "(%s)" (stgit-file-type-string new-type))))
          (t (format "(%s -> %s)"
                     (stgit-file-type-string old-type)
                     (stgit-file-type-string new-type))))))

(defun stgit-file-mode-change-string (old-perm new-perm)
  "Return string describing file mode change from OLD-PERM to NEW-PERM.
Cf. `stgit-file-type-change-string'."
  (setq old-perm (logand old-perm #o777)
        new-perm (logand new-perm #o777))
  (if (or (= old-perm new-perm)
          (zerop old-perm)
          (zerop new-perm))
      ""
    (let* ((modified       (logxor old-perm new-perm))
           (not-x-modified (logand (logxor old-perm new-perm) #o666)))
      (cond ((zerop modified) "")
            ((and (zerop not-x-modified)
                  (or (and (eq #o111 (logand old-perm #o111))
                           (propertize "-x" 'face 'stgit-file-permission-face))
                      (and (eq #o111 (logand new-perm #o111))
                           (propertize "+x" 'face
                                       'stgit-file-permission-face)))))
            (t (concat (propertize (format "%o" old-perm)
                                   'face 'stgit-file-permission-face)
                       (propertize " -> "
                                   'face 'stgit-description-face)
                       (propertize (format "%o" new-perm)
                                   'face 'stgit-file-permission-face)))))))

(defstruct (stgit-file
            (:conc-name stgit-file->))
  old-perm new-perm copy-or-rename cr-score cr-from cr-to status file)

(defun stgit-describe-copy-or-rename (file)
  (let ((arrow (concat " " (propertize "->" 'face 'stgit-description-face) " "))
        from to common-head common-tail)

    (when stgit-abbreviate-copies-and-renames
      (setq from (split-string (stgit-file->cr-from file) "/")
            to   (split-string (stgit-file->cr-to   file) "/"))

      (while (and from to (cdr from) (cdr to)
                  (string-equal (car from) (car to)))
        (setq common-head (cons (car from) common-head)
              from        (cdr from)
              to          (cdr to)))
      (setq common-head (nreverse common-head)
            from        (nreverse from)
            to          (nreverse to))
      (while (and from to (cdr from) (cdr to)
                  (string-equal (car from) (car to)))
        (setq common-tail (cons (car from) common-tail)
              from        (cdr from)
              to          (cdr to)))
      (setq from (nreverse from)
            to   (nreverse to)))

    (if (or common-head common-tail)
        (concat (if common-head
                    (mapconcat #'identity common-head "/")
                  "")
                (if common-head "/" "")
                (propertize "{" 'face 'stgit-description-face)
                (mapconcat #'identity from "/")
                arrow
                (mapconcat #'identity to "/")
                (propertize "}" 'face 'stgit-description-face)
                (if common-tail "/" "")
                (if common-tail
                    (mapconcat #'identity common-tail "/")
                  ""))
      (concat (stgit-file->cr-from file) arrow (stgit-file->cr-to file)))))

(defun stgit-file-pp (file)
  (let ((start (point))
        (spec (format-spec-make
               ?s (stgit-file-status-code-as-string file)
               ?m (stgit-file-mode-change-string
                   (stgit-file->old-perm file)
                   (stgit-file->new-perm file))
               ?n (if (stgit-file->copy-or-rename file)
                      (stgit-describe-copy-or-rename file)
                    (stgit-file->file file))
               ?c (propertize (stgit-file-type-change-string
                               (stgit-file->old-perm file)
                               (stgit-file->new-perm file))
                              'face 'stgit-description-face))))
    (stgit-insert-without-trailing-whitespace
     (format-spec stgit-file-line-format spec))
    (add-text-properties start (point)
                         (list 'entry-type 'file
                               'file-data file))))

(defun stgit-find-copies-harder-diff-arg ()
  "Return the flag to use with `git-diff' depending on the
`stgit-find-copies-harder' flag."
  (if stgit-find-copies-harder "--find-copies-harder" "-C"))

(defun stgit-insert-ls-files (args file-flag)
  (let ((start (point)))
    (apply 'stgit-run-git
           (append '("ls-files" "--exclude-standard" "-z") args))
    (goto-char start)
    (while (looking-at "\\([^\0]*\\)\0")
      (let ((name-len (- (match-end 0) (match-beginning 0))))
        (insert ":0 0 0000000000000000000000000000000000000000 0000000000000000000000000000000000000000 " file-flag "\0")
        (forward-char name-len)))))

(defun stgit-process-files (callback)
  (goto-char (point-min))
  (when (looking-at "[0-9A-Fa-f]\\{40\\}\0")
    (goto-char (match-end 0)))
  (while (looking-at ":\\([0-7]+\\) \\([0-7]+\\) [0-9A-Fa-f]\\{40\\} [0-9A-Fa-f]\\{40\\} ")
    (let ((old-perm (string-to-number (match-string 1) 8))
          (new-perm (string-to-number (match-string 2) 8)))
      (goto-char (match-end 0))
      (let ((file
             (cond ((looking-at
                     "\\([CR]\\)\\([0-9]*\\)\0\\([^\0]*\\)\0\\([^\0]*\\)\0")
                    (let* ((patch-status (stgit-patch->status patch))
                           (file-subexp  (if (eq patch-status 'unapplied)
                                             3
                                           4))
                           (file         (match-string file-subexp)))
                      (make-stgit-file
                       :old-perm       old-perm
                       :new-perm       new-perm
                       :copy-or-rename t
                       :cr-score       (string-to-number (match-string 2))
                       :cr-from        (match-string 3)
                       :cr-to          (match-string 4)
                       :status         (stgit-file-status-code
                                        (match-string 1))
                       :file           file)))
                   ((looking-at "\\([ABD-QS-Z]\\)\0\\([^\0]*\\)\0")
                    (make-stgit-file
                     :old-perm       old-perm
                     :new-perm       new-perm
                     :copy-or-rename nil
                     :cr-score       nil
                     :cr-from        nil
                     :cr-to          nil
                     :status         (stgit-file-status-code
                                      (match-string 1))
                     :file           (match-string 2))))))
        (goto-char (match-end 0))
        (funcall callback file)))))


(defun stgit-insert-patch-files (patch)
  "Expand (show modification of) the patch PATCH after the line
at point."
  (let* ((patchsym (stgit-patch->name patch))
         (end      (point-marker))
         (args     (list "-z" (stgit-find-copies-harder-diff-arg)))
         (ewoc     (ewoc-create #'stgit-file-pp nil nil t)))
    (set-marker-insertion-type end t)
    (setf (stgit-patch->files-ewoc patch) ewoc)
    (with-temp-buffer
      (let ((standard-output (current-buffer)))
        (apply 'stgit-run-git
               (cond ((eq patchsym :work)
                      `("diff-files" "-0" ,@args))
                     ((eq patchsym :index)
                      `("diff-index" ,@args "--cached" "HEAD"))
                     (t
                      `("diff-tree" ,@args "-r" ,(stgit-id patchsym)))))

        (when (and (eq patchsym :work))
          (when stgit-show-ignored
            (stgit-insert-ls-files '("--ignored" "--others") "I"))
          (when stgit-show-unknown
            (stgit-insert-ls-files '("--directory" "--no-empty-directory"
                                     "--others")
                                   "X"))
          (sort-regexp-fields nil ":[^\0]*\0\\([^\0]*\\)\0" "\\1"
                              (point-min) (point-max)))

        (stgit-process-files (lambda (file) (ewoc-enter-last ewoc file)))

        (unless (ewoc-nth ewoc 0)
          (ewoc-set-hf ewoc ""
                       (concat "    "
                               (propertize "<no files>"
                                           'face 'stgit-description-face)
                               "\n")))))
    (goto-char end)))

(defun stgit-find-file (&optional other-window)
  (let* ((file (or (stgit-patched-file-at-point)
                   (error "No file at point")))
         (filename (expand-file-name (stgit-file->file file))))
    (unless (file-exists-p filename)
      (error "File does not exist"))
    (funcall (if other-window 'find-file-other-window 'find-file)
             filename)
    (when (eq (stgit-file->status file) 'unmerged)
      (smerge-mode 1))))

(defun stgit-expand (&optional patches collapse)
  "Show the contents of marked patches, or the patch at point.

See also `stgit-collapse'.

Non-interactively, operate on PATCHES, and collapse instead of
expand if COLLAPSE is not nil."
  (interactive (list (stgit-patches-marked-or-at-point t)))
  (stgit-assert-mode)
  (let ((patches-diff (funcall (if collapse #'intersection #'set-difference)
                               patches stgit-expanded-patches)))
    (setq stgit-expanded-patches
          (if collapse
              (set-difference stgit-expanded-patches patches-diff)
            (append stgit-expanded-patches patches-diff)))
    (ewoc-map #'(lambda (patch)
                  (memq (stgit-patch->name patch) patches-diff))
              stgit-ewoc))
  (move-to-column (stgit-goal-column)))

(defun stgit-collapse (&optional patches)
  "Hide the contents of marked patches, or the patch at point.

See also `stgit-expand'."
  (interactive (list (stgit-patches-marked-or-at-point t)))
  (stgit-assert-mode)
  (stgit-expand patches t))

(defun stgit-select-patch ()
  (let ((patchname (stgit-patch-name-at-point)))
    (stgit-expand (list patchname)
                  (memq patchname stgit-expanded-patches))))

(defun stgit-expand-directory (file)
  (let* ((patch (stgit-patch-at-point))
         (ewoc (stgit-patch->files-ewoc patch))
         (node (ewoc-locate ewoc))
         (filename (stgit-file->file file))
         (start (make-marker))
         (end (make-marker)))

    (save-excursion
      (forward-line 1)
      (set-marker start (point))
      (set-marker end (point))
      (set-marker-insertion-type end t))

    (assert (string-match "/$" filename))
    ;; remove trailing "/"
    (setf (stgit-file->file file) (substring filename 0 -1))
    (ewoc-invalidate ewoc node)

    (with-temp-buffer
      (let ((standard-output (current-buffer)))
        (stgit-insert-ls-files (list "--directory" "--others"
                                     "--no-empty-directory" "--"
                                     filename)
                               "X")
        (stgit-process-files (lambda (f)
                               (setq node (ewoc-enter-after ewoc node f))))))

    (let ((inhibit-read-only t))
      (put-text-property start end 'patch-data patch))))

(defun stgit-select-file ()
  (let* ((file (or (stgit-patched-file-at-point)
                   (error "No file at point")))
         (filename (stgit-file->file file)))
    (if (string-match "/$" filename)
        (stgit-expand-directory file)
      (stgit-find-file))))

(defun stgit-select ()
  "With point on a patch, toggle showing files in the patch.

With point on a file, open the associated file. Opens the target
file for (applied) copies and renames."
  (interactive)
  (stgit-assert-mode)
  (case (get-text-property (point) 'entry-type)
    ('patch
     (stgit-select-patch))
    ('file
     (stgit-select-file))
    (t
     (error "No patch or file on line"))))

(defun stgit-find-file-other-window ()
  "Open file at point in other window"
  (interactive)
  (stgit-assert-mode)
  (stgit-find-file t))

(defun stgit-find-file-merge ()
  "Open file at point and merge it using `smerge-ediff'."
  (interactive)
  (stgit-assert-mode)
  (stgit-find-file t)
  (smerge-ediff))

(defun stgit-quit ()
  "Hide the stgit buffer."
  (interactive)
  (stgit-assert-mode)
  (bury-buffer))

(defun stgit-git-status ()
  "Show status using `git-status'."
  (interactive)
  (stgit-assert-mode)
  (unless (fboundp 'git-status)
    (error "The stgit-git-status command requires git-status"))
  (let ((dir default-directory))
    (save-selected-window
      (pop-to-buffer nil)
      (git-status dir))))

(defun stgit-goal-column ()
  "Return goal column for the current line"
  (case (get-text-property (point) 'entry-type)
    ('patch 2)
    ('file 4)
    (t 0)))

(defun stgit-next-line (&optional arg)
  "Move cursor vertically down ARG lines"
  (interactive "p")
  (stgit-assert-mode)
  (next-line arg)
  (move-to-column (stgit-goal-column)))

(defun stgit-previous-line (&optional arg)
  "Move cursor vertically up ARG lines"
  (interactive "p")
  (stgit-assert-mode)
  (previous-line arg)
  (move-to-column (stgit-goal-column)))

(defun stgit-next-patch (&optional arg)
  "Move cursor down ARG patches."
  (interactive "p")
  (stgit-assert-mode)
  (ewoc-goto-next stgit-ewoc (or arg 1))
  (move-to-column goal-column))

(defun stgit-previous-patch (&optional arg)
  "Move cursor up ARG patches."
  (interactive "p")
  (stgit-assert-mode)
  (ewoc-goto-prev stgit-ewoc (or arg 1))
  (move-to-column goal-column))

(defvar stgit-mode-hook nil
  "Run after `stgit-mode' is setup.")

(defvar stgit-mode-map nil
  "Keymap for StGit major mode.")

(unless stgit-mode-map
  (let ((diff-map   (make-sparse-keymap))
        (toggle-map (make-sparse-keymap)))
    (suppress-keymap diff-map)
    (mapc (lambda (arg) (define-key diff-map (car arg) (cdr arg)))
          '(("b" .        stgit-diff-base)
            ("c" .        stgit-diff-combined)
            ("m" .        stgit-find-file-merge)
            ("o" .        stgit-diff-ours)
            ("r" .        stgit-diff-range)
            ("t" .        stgit-diff-theirs)))
    (suppress-keymap toggle-map)
    (mapc (lambda (arg) (define-key toggle-map (car arg) (cdr arg)))
          '(("n" .        stgit-toggle-patch-names)
            ("t" .        stgit-toggle-worktree)
            ("i" .        stgit-toggle-ignored)
            ("u" .        stgit-toggle-unknown)))
    (setq stgit-mode-map (make-keymap))
    (suppress-keymap stgit-mode-map)
    (mapc (lambda (arg) (define-key stgit-mode-map (car arg) (cdr arg)))
          `((" " .        stgit-mark-down)
            ("m" .        stgit-mark-down)
            ("\d" .       stgit-unmark-up)
            ("u" .        stgit-unmark-down)
            ("?" .        stgit-help)
            ("h" .        stgit-help)
            ("\C-p" .     stgit-previous-line)
            ("\C-n" .     stgit-next-line)
            ([up] .       stgit-previous-line)
            ([down] .     stgit-next-line)
            ("p" .        stgit-previous-patch)
            ("n" .        stgit-next-patch)
            ("\M-{" .     stgit-previous-patch)
            ("\M-}" .     stgit-next-patch)
            ("s" .        stgit-git-status)
            ("g" .        stgit-reload-or-repair)
            ("r" .        stgit-refresh)
            ("\C-c\C-r" . stgit-rename)
            ("e" .        stgit-edit)
            ("M" .        stgit-move-patches)
            ("S" .        stgit-squash)
            ("N" .        stgit-new)
            ("c" .        stgit-new-and-refresh)
            ("\C-c\C-c" . stgit-commit)
            ("\C-c\C-u" . stgit-uncommit)
            ("U" .        stgit-revert)
            ("R" .        stgit-resolve-file)
            ("\r" .       stgit-select)
            ("+" .        stgit-expand)
            ("-" .        stgit-collapse)
            ("o" .        stgit-find-file-other-window)
            ("i" .        stgit-toggle-index)
            (">" .        stgit-push-next)
            ("<" .        stgit-pop-next)
            ("P" .        stgit-push-or-pop)
            ("G" .        stgit-goto)
            ("=" .        stgit-diff)
            ("D" .        stgit-delete)
            ([?\C-/] .    stgit-undo)
            ("\C-_" .     stgit-undo)
            ([?\C-c ?\C-/] . stgit-redo)
            ("\C-c\C-_" . stgit-redo)
            ("B" .        stgit-branch)
            ("\C-c\C-b" . stgit-rebase)
            ("t" .        ,toggle-map)
            ("d" .        ,diff-map)
            ("q" .        stgit-quit))))

  (let ((at-unmerged-file '(let ((file (stgit-patched-file-at-point)))
                             (and file (eq (stgit-file->status file)
                                           'unmerged))))
        (patch-collapsed-p '(lambda (p) (not (memq p stgit-expanded-patches)))))
    (easy-menu-define stgit-menu stgit-mode-map
      "StGit Menu"
      `("StGit"
        ["Reload" stgit-reload-or-repair
         :help "Reload StGit status from disk"]
        ["Repair" stgit-repair
         :keys "\\[universal-argument] \\[stgit-reload-or-repair]"
         :help "Repair StGit metadata"]
        "-"
        ["Undo" stgit-undo t]
        ["Redo" stgit-redo t]
        "-"
        ["Git status" stgit-git-status :active (fboundp 'git-status)]
        "-"
        ["New patch" stgit-new-and-refresh
         :help "Create a new patch from changes in index or work tree"
         :active (not (and (stgit-index-empty-p) (stgit-work-tree-empty-p)))]
        ["New empty patch" stgit-new
         :help "Create a new, empty patch"]
        ["(Un)mark patch" stgit-toggle-mark
         :label (if (memq (stgit-patch-name-at-point nil t)
                          stgit-marked-patches)
                    "Unmark patch" "Mark patch")
         :active (stgit-patch-name-at-point nil t)]
        ["Expand/collapse patch"
         (let ((patches (stgit-patches-marked-or-at-point)))
           (if (member-if ,patch-collapsed-p patches)
               (stgit-expand patches)
             (stgit-collapse patches)))
         :label (if (member-if ,patch-collapsed-p
                               (stgit-patches-marked-or-at-point))
                    "Expand patches"
                  "Collapse patches")
         :active (stgit-patches-marked-or-at-point)]
        ["Edit patch" stgit-edit
         :help "Edit patch comment"
         :active (stgit-patch-name-at-point nil t)]
        ["Rename patch" stgit-rename :active (stgit-patch-name-at-point nil t)]
        ["Push/pop patch" stgit-push-or-pop
         :label (if (subsetp (stgit-patches-marked-or-at-point nil t)
                             (stgit-applied-patchsyms t))
                    "Pop patches" "Push patches")]
        ["Delete patches" stgit-delete
         :active (stgit-patches-marked-or-at-point nil t)]
        "-"
        ["Move patches" stgit-move-patches
         :active stgit-marked-patches
         :help "Move marked patch(es) to point"]
        ["Squash patches" stgit-squash
         :active (> (length stgit-marked-patches) 1)
         :help "Merge marked patches into one"]
        "-"
        ["Refresh top patch" stgit-refresh
         :active (not (and (stgit-index-empty-p) (stgit-work-tree-empty-p)))
         :help "Refresh the top patch with changes in index or work tree"]
        ["Refresh this patch" (stgit-refresh t)
         :keys "\\[universal-argument] \\[stgit-refresh]"
         :help "Refresh marked patch with changes in index or work tree"
         :active (and (not (and (stgit-index-empty-p)
                                (stgit-work-tree-empty-p)))
                      (stgit-patch-name-at-point nil t))]
        "-"
        ["Find file" stgit-select
         :active (eq (get-text-property (point) 'entry-type) 'file)]
        ["Open file" stgit-find-file-other-window
         :active (eq (get-text-property (point) 'entry-type) 'file)]
        ["Toggle file index" stgit-toggle-index
         :active (and (eq (get-text-property (point) 'entry-type) 'file)
                      (memq (stgit-patch-name-at-point) '(:work :index)))
         :label (if (eq (stgit-patch-name-at-point) :work)
                    "Move change to index"
                  "Move change to work tree")]
        "-"
        ["Show diff" stgit-diff
         :active (get-text-property (point) 'entry-type)]
        ["Show diff for range of applied patches" stgit-diff-range
         :active (= (length stgit-marked-patches) 1)]
        ("Merge"
         :active (stgit-git-index-unmerged-p)
         ["Combined diff" stgit-diff-combined
          :active (memq (stgit-patch-name-at-point nil nil) '(:work :index))]
         ["Diff against base" stgit-diff-base
          :help "Show diff against the common base"
          :active (memq (stgit-patch-name-at-point nil nil) '(:work :index))]
         ["Diff against ours" stgit-diff-ours
          :help "Show diff against our branch"
          :active (memq (stgit-patch-name-at-point nil nil) '(:work :index))]
         ["Diff against theirs" stgit-diff-theirs
          :help "Show diff against their branch"
          :active (memq (stgit-patch-name-at-point nil nil) '(:work :index))]
         "-"
         ["Interactive merge" stgit-find-file-merge
          :help "Interactively merge the file"
          :active ,at-unmerged-file]
         ["Resolve file" stgit-resolve-file
          :help "Mark file conflict as resolved"
          :active ,at-unmerged-file]
         )
        "-"
        ["Show index & work tree" stgit-toggle-worktree :style toggle
         :selected stgit-show-worktree]
        ["Show unknown files" stgit-toggle-unknown :style toggle
         :selected stgit-show-unknown :active stgit-show-worktree]
        ["Show ignored files" stgit-toggle-ignored :style toggle
         :selected stgit-show-ignored :active stgit-show-worktree]
        ["Show patch names" stgit-toggle-patch-names :style toggle
         :selected stgit-show-patch-names]
        "-"
        ["Switch branches" stgit-branch t
         :help "Switch to or create another branch"]
        ["Rebase branch" stgit-rebase t
         :help "Rebase the current branch"]
        ))))

;; disable tool bar editing buttons
(put 'stgit-mode 'mode-class 'special)

(defun stgit-mode ()
  "Major mode for interacting with StGit.

Start StGit using \\[stgit].

Basic commands:
\\<stgit-mode-map>\
\\[stgit-help]  Show this help text
\\[stgit-quit]  Hide the StGit buffer
\\[describe-bindings]   Show all key bindings

\\[stgit-reload-or-repair]      Reload the StGit buffer
\\[universal-argument] \\[stgit-reload-or-repair]       Repair StGit metadata

\\[stgit-undo]  Undo most recent StGit operation
\\[stgit-redo]  Undo recent undo

\\[stgit-git-status]    Run `git-status' (if available)

Movement commands:
\\[stgit-previous-line] Move to previous line
\\[stgit-next-line]     Move to next line
\\[stgit-previous-patch]        Move to previous patch
\\[stgit-next-patch]    Move to next patch

\\[stgit-mark-down]     Mark patch and move down
\\[stgit-unmark-up]     Unmark patch and move up
\\[stgit-unmark-down]   Unmark patch and move down

Commands for patches:
\\[stgit-select]        Toggle showing changed files in patch
\\[stgit-refresh]       Refresh patch with changes in index or work tree
\\[stgit-diff]  Show the patch log and diff

\\[stgit-expand]        Show changes in marked patches
\\[stgit-collapse]      Hide changes in marked patches

\\[stgit-new-and-refresh]       Create a new patch from index or work tree
\\[stgit-new]   Create a new, empty patch

\\[stgit-rename]        Rename patch
\\[stgit-edit]  Edit patch description
\\[stgit-delete]        Delete patch(es)

\\[stgit-revert]        Revert all changes in index or work tree
\\[stgit-toggle-index]  Toggle all changes between index and work tree

\\[stgit-push-next]     Push next patch onto stack
\\[stgit-pop-next]      Pop current patch from stack
\\[stgit-push-or-pop]   Push or pop marked patches
\\[stgit-goto]  Make patch at point current by popping or pushing

\\[stgit-squash]        Squash (meld together) patches
\\[stgit-move-patches]  Move marked patches to point

\\[stgit-commit]        Commit patch(es)
\\[stgit-uncommit]      Uncommit patch(es)

Commands for files:
\\[stgit-select]        Open the file in this window
\\[stgit-find-file-other-window]        Open the file in another window
\\[stgit-diff]  Show the file's diff

\\[stgit-toggle-index]  Toggle change between index and work tree
\\[stgit-revert]        Revert changes to file

Display commands:
\\[stgit-toggle-patch-names]    Toggle showing patch names
\\[stgit-toggle-worktree]       Toggle showing index and work tree
\\[stgit-toggle-unknown]        Toggle showing unknown files
\\[stgit-toggle-ignored]        Toggle showing ignored files

Commands for diffs:
\\[stgit-diff]  Show diff of patch or file
\\[stgit-diff-range]    Show diff for range of patches
\\[stgit-diff-base]     Show diff against the merge base
\\[stgit-diff-ours]     Show diff against our branch
\\[stgit-diff-theirs]   Show diff against their branch

  With one prefix argument (e.g., \\[universal-argument] \\[stgit-diff]), \
ignore space changes.
  With two prefix arguments (e.g., \\[universal-argument] \
\\[universal-argument] \\[stgit-diff]), ignore all space changes.

Commands for merge conflicts:
\\[stgit-find-file-merge]       Resolve conflicts using `smerge-ediff'
\\[stgit-resolve-file]  Mark unmerged file as resolved

Commands for branches:
\\[stgit-branch]        Switch to or create another branch
\\[stgit-rebase]        Rebase the current branch

Customization variables:
`stgit-abbreviate-copies-and-renames'
`stgit-default-show-patch-names'
`stgit-default-show-worktree'
`stgit-find-copies-harder'
`stgit-show-worktree-mode'

See also \\[customize-group] for the \"stgit\" group."
  (kill-all-local-variables)
  (buffer-disable-undo)
  (setq mode-name "StGit"
        major-mode 'stgit-mode
        goal-column 2)
  (use-local-map stgit-mode-map)
  (set (make-local-variable 'list-buffers-directory) default-directory)
  (set (make-local-variable 'stgit-marked-patches) nil)
  (set (make-local-variable 'stgit-expanded-patches) (list :work :index))
  (set (make-local-variable 'stgit-show-patch-names)
       stgit-default-show-patch-names)
  (set (make-local-variable 'stgit-show-worktree) stgit-default-show-worktree)
  (set (make-local-variable 'stgit-index-node) nil)
  (set (make-local-variable 'stgit-worktree-node) nil)
  (set (make-local-variable 'parse-sexp-lookup-properties) t)
  (set-variable 'truncate-lines 't)
  (add-hook 'after-save-hook 'stgit-update-saved-file)
  (run-hooks 'stgit-mode-hook))

(defun stgit-update-saved-file ()
  (let* ((file (expand-file-name buffer-file-name))
         (dir (file-name-directory file))
         (gitdir (condition-case nil (git-get-top-dir dir)
                   (error nil)))
         (buffer (and gitdir (stgit-find-buffer gitdir))))
    (when buffer
      (with-current-buffer buffer
        (stgit-refresh-worktree)))))

(defun stgit-add-mark (patchsym)
  "Mark the patch PATCHSYM."
  (setq stgit-marked-patches (cons patchsym stgit-marked-patches)))

(defun stgit-remove-mark (patchsym)
  "Unmark the patch PATCHSYM."
  (setq stgit-marked-patches (delq patchsym stgit-marked-patches)))

(defun stgit-clear-marks ()
  "Unmark all patches."
  (setq stgit-marked-patches '()))

(defun stgit-patch-at-point (&optional cause-error)
  (get-text-property (point) 'patch-data))

(defun stgit-patch-name-at-point (&optional cause-error only-patches)
  "Return the patch name on the current line as a symbol.
If CAUSE-ERROR is not nil, signal an error if none found.
If ONLY-PATCHES is not nil, only allow real patches, and not
index or work tree."
  (let ((patch (stgit-patch-at-point)))
    (and patch
         only-patches
         (memq (stgit-patch->status patch) '(work index))
         (setq patch nil))
    (cond (patch
           (stgit-patch->name patch))
          (cause-error
           (error "No patch on this line")))))

(defun stgit-patched-file-at-point ()
  (get-text-property (point) 'file-data))

(defun stgit-patches-marked-or-at-point (&optional cause-error only-patches)
  "Return the symbols of the marked patches, or the patch on the current line.
If CAUSE-ERRROR is not nil, signal an error if none found.
If ONLY-PATCHES is not nil, do not include index or work tree."
  (if stgit-marked-patches
      stgit-marked-patches
    (let ((patch (stgit-patch-name-at-point nil only-patches)))
      (cond (patch (list patch))
            (cause-error (error "No patches marked or at this line"))
            (t nil)))))

(defun stgit-goto-patch (patchsym &optional file)
  "Move point to the line containing patch PATCHSYM.
If that patch cannot be found, do nothing.

If the patch was found and FILE is not nil, instead move to that
file's line. If FILE cannot be found, stay on the line of
PATCHSYM."
  (let ((node (ewoc-nth stgit-ewoc 0)))
    (while (and node (not (eq (stgit-patch->name (ewoc-data node))
                              patchsym)))
      (setq node (ewoc-next stgit-ewoc node)))
    (when (and node file)
      (let* ((file-ewoc (stgit-patch->files-ewoc (ewoc-data node)))
             (file-node (ewoc-nth file-ewoc 0)))
        (while (and file-node (not (equal (stgit-file->file (ewoc-data file-node)) file)))
          (setq file-node (ewoc-next file-ewoc file-node)))
        (when file-node
          (ewoc-goto-node file-ewoc file-node)
          (move-to-column (stgit-goal-column))
          (setq node nil))))
    (when node
      (ewoc-goto-node stgit-ewoc node)
      (move-to-column goal-column))))

(defun stgit-init ()
  "Run stg init."
  (interactive)
  (stgit-assert-mode)
  (stgit-capture-output nil
    (stgit-run "init"))
  (stgit-reload))

(defun stgit-toggle-mark ()
  "Toggle mark on the patch under point."
  (interactive)
  (stgit-assert-mode)
  (if (memq (stgit-patch-name-at-point t t) stgit-marked-patches)
      (stgit-unmark)
    (stgit-mark)))

(defun stgit-mark ()
  "Mark the patch under point."
  (interactive)
  (stgit-assert-mode)
  (let* ((node (ewoc-locate stgit-ewoc))
         (patch (ewoc-data node))
         (name (stgit-patch->name patch)))
    (when (eq name :work)
      (error "Cannot mark the work tree"))
    (when (eq name :index)
      (error "Cannot mark the index"))
    (stgit-add-mark (stgit-patch->name patch))
    (let ((column (current-column)))
      (ewoc-invalidate stgit-ewoc node)
      (move-to-column column))))

(defun stgit-mark-down ()
  "Mark the patch under point and move to the next patch."
  (interactive)
  (stgit-mark)
  (stgit-next-patch))

(defun stgit-unmark ()
  "Remove mark from the patch on the current line."
  (interactive)
  (stgit-assert-mode)
  (let* ((node (ewoc-locate stgit-ewoc))
         (patch (ewoc-data node)))
    (stgit-remove-mark (stgit-patch->name patch))
    (let ((column (current-column)))
      (ewoc-invalidate stgit-ewoc node)
      (move-to-column column))))

(defun stgit-unmark-up ()
  "Remove mark from the patch on the previous line."
  (interactive)
  (stgit-assert-mode)
  (stgit-previous-patch)
  (stgit-unmark))

(defun stgit-unmark-down ()
  "Remove mark from the patch on the current line."
  (interactive)
  (stgit-assert-mode)
  (stgit-unmark)
  (stgit-next-patch))

(defun stgit-rename (name)
  "Rename the patch under point to NAME."
  (interactive (list
                (read-string "Patch name: "
                             (symbol-name (stgit-patch-name-at-point t t)))))
  (stgit-assert-mode)
  (let ((old-patchsym (stgit-patch-name-at-point t t)))
    (stgit-capture-output nil
      (stgit-run "rename" old-patchsym name))
    (let ((name-sym (intern name)))
      (when (memq old-patchsym stgit-expanded-patches)
        (setq stgit-expanded-patches
              (cons name-sym (delq old-patchsym stgit-expanded-patches))))
      (when (memq old-patchsym stgit-marked-patches)
        (setq stgit-marked-patches
              (cons name-sym (delq old-patchsym stgit-marked-patches))))
      (stgit-reload)
      (stgit-goto-patch name-sym))))

(defun stgit-reload-or-repair (repair)
  "Update the contents of the StGit buffer (`stgit-reload').

With a prefix argument, repair the StGit metadata if the branch
was modified with git commands (`stgit-repair')."
  (interactive "P")
  (stgit-assert-mode)
  (if repair
      (stgit-repair)
    (stgit-reload)))

(defun stgit-repair ()
  "Run stg repair."
  (interactive)
  (stgit-assert-mode)
  (stgit-capture-output nil
    (stgit-run "repair"))
  (stgit-reload))

(defun stgit-available-branches (&optional all)
  "Returns a list of the names of the available stg branches as strings.

If ALL is not nil, also return non-stgit branches."
  (let ((output (with-output-to-string
                  (stgit-run "branch" "--list")))
        (pattern (format "^>?\\s-+%c\\s-+\\(\\S-+\\)"
                         (if all ?. ?s)))
        (start 0)
        result)
    (while (string-match pattern output start)
      (setq result (cons (match-string 1 output) result))
      (setq start (match-end 0)))
    result))

(defun stgit-branch (branch)
  "Switch to or create branch BRANCH."
  (interactive (list (completing-read "Switch to branch: "
                                      (stgit-available-branches))))
  (stgit-assert-mode)
  (when (cond ((equal branch (stgit-current-branch))
               (error "Branch is already current"))
              ((member branch (stgit-available-branches t))
               (stgit-capture-output nil (stgit-run "branch" "--" branch))
               t)
              ((not (string-match stgit-allowed-branch-name-re branch))
               (error "Invalid branch name"))
              ((yes-or-no-p (format "Create branch \"%s\"? " branch))
               (stgit-capture-output nil (stgit-run "branch" "--create" "--"
                                                    branch))
               t))
    (stgit-reload)))

(defun stgit-available-refs (&optional omit-stgit)
  "Returns a list of the available git refs.
If OMIT-STGIT is not nil, filter out \"resf/heads/*.stgit\"."
  (let* ((output (with-output-to-string
                   (stgit-run-git-silent "for-each-ref" "--format=%(refname)"
                                         "refs/tags" "refs/heads"
                                         "refs/remotes")))
         (result (split-string output "\n" t)))
    (mapcar (lambda (s)
              (if (string-match "^refs/\\(heads\\|tags\\|remotes\\)/" s)
                  (substring s (match-end 0))
                s))
            (if omit-stgit
                (delete-if (lambda (s)
                             (string-match "^refs/heads/.*\\.stgit$" s))
                           result)
              result))))

(defun stgit-parent-branch ()
  "Return the parent branch of the current stg branch as per
git-config setting branch.<branch>.stgit.parentbranch."
  (let ((output (with-output-to-string
                  (stgit-run-git-silent "config"
                                        (format "branch.%s.stgit.parentbranch"
                                                (stgit-current-branch))))))
    (when (string-match ".*" output)
      (match-string 0 output))))

(defun stgit-rebase (new-base)
  "Rebase the current branch to NEW-BASE.

Interactively, first ask which branch to rebase to. Defaults to
what git-config branch.<branch>.stgit.parentbranch is set to."
  (interactive (list (completing-read "Rebase to: "
                                      (stgit-available-refs t)
                                      nil nil
                                      (stgit-parent-branch))))
  (stgit-assert-mode)
  (stgit-capture-output nil (stgit-run "rebase" new-base))
  (stgit-reload))

(defun stgit-commit (count)
  "Run stg commit on COUNT commits.
Interactively, the prefix argument is used as COUNT.
A negative COUNT will uncommit instead."
  (interactive "p")
  (stgit-assert-mode)
  (if (< count 0)
      (stgit-uncommit (- count))
    (stgit-capture-output nil (stgit-run "commit" "-n" count))
    (stgit-reload)))

(defun stgit-uncommit (count)
  "Run stg uncommit on COUNT commits.
Interactively, the prefix argument is used as COUNT.
A negative COUNT will commit instead."
  (interactive "p")
  (stgit-assert-mode)
  (if (< count 0)
      (stgit-commit (- count))
    (stgit-capture-output nil (stgit-run "uncommit" "-n" count))
    (stgit-reload)))

(defun stgit-neighbour-file ()
  "Return the file name of the next file after point, or the
previous file if point is at the last file within a patch."
  (let ((old-point (point))
        neighbour-file)
    (and (zerop (forward-line 1))
         (let ((f (stgit-patched-file-at-point)))
           (and f (setq neighbour-file (stgit-file->file f)))))
    (goto-char old-point)
    (unless neighbour-file
      (and (zerop (forward-line -1))
           (let ((f (stgit-patched-file-at-point)))
             (and f (setq neighbour-file (stgit-file->file f)))))
      (goto-char old-point))
    neighbour-file))

(defun stgit-revert-file ()
  "Revert the file at point, which must be in the index or the
working tree."
  (interactive)
  (stgit-assert-mode)
  (let* ((patched-file (or (stgit-patched-file-at-point)
                           (error "No file on the current line")))
         (patch-name   (stgit-patch-name-at-point))
         (file-status  (stgit-file->status patched-file))
         (rm-file      (cond ((stgit-file->copy-or-rename patched-file)
                              (stgit-file->cr-to patched-file))
                             ((eq file-status 'add)
                              (stgit-file->file patched-file))))
         (co-file      (cond ((eq file-status 'rename)
                              (stgit-file->cr-from patched-file))
                             ((not (memq file-status '(copy add)))
                              (stgit-file->file patched-file))))
         (next-file    (stgit-neighbour-file)))

    (unless (memq patch-name '(:work :index))
      (error "No index or working tree file on this line"))

    (when (eq file-status 'ignore)
      (error "Cannot revert ignored files"))

    (when (eq file-status 'unknown)
      (error "Cannot revert unknown files"))

    (let ((nfiles (+ (if rm-file 1 0) (if co-file 1 0))))
      (when (yes-or-no-p (format "Revert %d file%s? "
                                 nfiles
                                 (if (= nfiles 1) "" "s")))
        (stgit-capture-output nil
          (when rm-file
            (stgit-run-git "rm" "-f" "-q" "--" rm-file))
          (when co-file
            (stgit-run-git "checkout" "HEAD" co-file)))
        (stgit-reload)
        (stgit-goto-patch patch-name next-file)))))

(defun stgit-revert ()
  "Revert the change at point, which must be the index, the work
tree, or a single change in either."
  (interactive)
  (stgit-assert-mode)
  (let ((patched-file (stgit-patched-file-at-point)))
    (if patched-file
        (stgit-revert-file)
      (let* ((patch-name (or (stgit-patch-name-at-point)
                             (error "No patch or file at point")))
             (patch-desc (case patch-name
                           (:index "index")
                           (:work  "work tree")
                           (t (error (substitute-command-keys
                                      "Use \\[stgit-delete] to delete a patch"))))))
        (when (if (eq patch-name :work)
                  (stgit-work-tree-empty-p)
                (stgit-index-empty-p))
          (error (format "There are no changes in the %s to revert"
                         patch-desc)))
        (and (eq patch-name :index)
             (not (stgit-work-tree-empty-p))
             (error "Cannot revert index as work tree contains unstaged changes"))

        (when (yes-or-no-p (format "Revert all changes in the %s? "
                                   patch-desc))
          (if (eq patch-name :index)
              (stgit-run-git-silent "reset" "--hard" "-q")
            (stgit-run-git-silent "checkout" "--" "."))
          (stgit-refresh-index)
          (stgit-refresh-worktree)
          (stgit-goto-patch patch-name))))))

(defun stgit-resolve-file ()
  "Resolve conflict in the file at point."
  (interactive)
  (stgit-assert-mode)
  (let* ((patched-file (stgit-patched-file-at-point))
         (patch        (stgit-patch-at-point))
         (patch-name   (and patch (stgit-patch->name patch)))
         (status       (and patched-file (stgit-file->status patched-file))))

    (unless (memq patch-name '(:work :index))
      (error "No index or working tree file on this line"))

    (unless (eq status 'unmerged)
      (error "No conflict to resolve at the current line"))

    (stgit-capture-output nil
      (stgit-move-change-to-index (stgit-file->file patched-file)))

    (stgit-reload)))

(defun stgit-push-or-pop-patches (do-push npatches)
  "Push (if DO-PUSH is not nil) or pop (if DO-PUSH is nil)
NPATCHES patches, or all patches if NPATCHES is t."
  (stgit-assert-mode)
  (stgit-capture-output nil
    (apply 'stgit-run
           (if do-push "push" "pop")
           (if (eq npatches t)
               '("--all")
             (list "-n" npatches))))
  (stgit-reload)
  (stgit-refresh-git-status))

(defun stgit-push-next (npatches)
  "Push the first unapplied patch.
With numeric prefix argument, push that many patches."
  (interactive "p")
  (stgit-push-or-pop-patches t npatches))

(defun stgit-pop-next (npatches)
  "Pop the topmost applied patch.
With numeric prefix argument, pop that many patches.

If NPATCHES is t, pop all patches."
  (interactive "p")
  (stgit-push-or-pop-patches nil npatches))

(defun stgit-applied-patches (&optional only-patches)
  "Return a list of the applied patches.

If ONLY-PATCHES is not nil, exclude index and work tree."
  (let ((states (if only-patches
                    '(applied top)
                  '(applied top index work)))
        result)
    (ewoc-map (lambda (patch) (when (memq (stgit-patch->status patch) states)
                                (setq result (cons patch result))))
              stgit-ewoc)
    result))

(defun stgit-applied-patchsyms (&optional only-patches)
  "Return a list of the symbols of the applied patches.

If ONLY-PATCHES is not nil, exclude index and work tree."
  (mapcar #'stgit-patch->name (stgit-applied-patches only-patches)))

(defun stgit-push-or-pop ()
  "Push or pop the marked patches."
  (interactive)
  (stgit-assert-mode)
  (let* ((patchsyms (stgit-patches-marked-or-at-point t t))
         (applied-syms (stgit-applied-patchsyms t))
         (unapplied (set-difference patchsyms applied-syms)))
    (stgit-capture-output nil
      (apply 'stgit-run
             (if unapplied "push" "pop")
             "--"
             (stgit-sort-patches (if unapplied unapplied patchsyms)))))
  (stgit-reload))

(defun stgit-goto-target ()
  "Return the goto target a point; either a patchsym, :top,
or :bottom."
  (let ((patchsym (stgit-patch-name-at-point)))
    (cond ((memq patchsym '(:work :index)) nil)
          (patchsym)
          ((not (next-single-property-change (point) 'patch-data))
           :top)
          ((not (previous-single-property-change (point) 'patch-data))
           :bottom))))

(defun stgit-goto ()
  "Go to the patch on the current line.

Push or pop patches to make this patch topmost. Push or pop all
patches if used on a line after or before all patches."
  (interactive)
  (stgit-assert-mode)
  (let ((patchsym (stgit-goto-target)))
    (unless patchsym
      (error "No patch to go to on this line"))
    (case patchsym
      (:top    (stgit-push-or-pop-patches t t))
      (:bottom (stgit-push-or-pop-patches nil t))
      (t (stgit-capture-output nil
           (stgit-run "goto" patchsym))
         (stgit-reload)))))

(defun stgit-id (patchsym)
  "Return the git commit id for PATCHSYM.
If PATCHSYM is a keyword, returns PATCHSYM unmodified."
  (if (keywordp patchsym)
      patchsym
    (let ((result (with-output-to-string
                    (stgit-run-silent "id" patchsym))))
      (unless (string-match "^\\([0-9A-Fa-f]\\{40\\}\\)$" result)
        (error "Cannot find commit id for %s" patchsym))
      (match-string 1 result))))

(defun stgit-whitespace-diff-arg (arg)
  (when (numberp arg)
    (cond ((> arg 4) "--ignore-all-space")
          ((> arg 1) "--ignore-space-change"))))

(defun stgit-show-patch (unmerged-stage ignore-whitespace)
  "Show the patch on the current line.

UNMERGED-STAGE is the argument to `git-diff' that that selects
which stage to diff against in the case of unmerged files."
  (let ((space-arg (stgit-whitespace-diff-arg ignore-whitespace))
        (patch-name (stgit-patch-name-at-point t)))
    (stgit-capture-output "*StGit patch*"
      (case (get-text-property (point) 'entry-type)
        ('file
         (let* ((patched-file (stgit-patched-file-at-point))
                (patch-id (let ((id (stgit-id patch-name)))
                            (if (and (eq id :index)
                                     (eq (stgit-file->status patched-file)
                                         'unmerged))
                                :work
                              id)))
                (args (append (and space-arg (list space-arg))
                              (and (stgit-file->cr-from patched-file)
                                   (list (stgit-find-copies-harder-diff-arg)))
                              (cond ((eq patch-id :index)
                                     '("--cached"))
                                    ((eq patch-id :work)
                                     (list unmerged-stage))
                                    (t
                                     (list (concat patch-id "^") patch-id)))
                              '("--")
                              (if (stgit-file->copy-or-rename patched-file)
                                  (list (stgit-file->cr-from patched-file)
                                        (stgit-file->cr-to patched-file))
                                (list (stgit-file->file patched-file))))))
           (apply 'stgit-run-git "diff" args)))
        ('patch
         (let* ((patch-id (stgit-id patch-name)))
           (if (or (eq patch-id :index) (eq patch-id :work))
               (apply 'stgit-run-git "diff"
                      (stgit-find-copies-harder-diff-arg)
                      (append (and space-arg (list space-arg))
                              (if (eq patch-id :index)
                                  '("--cached")
                                (list unmerged-stage))))
             (let ((args (append '("show" "-O" "--patch-with-stat" "-O" "-M")
                                 (and space-arg (list "-O" space-arg))
                                 (list (stgit-patch-name-at-point)))))
               (apply 'stgit-run args)))))
        (t
         (error "No patch or file at point")))
      (with-current-buffer standard-output
        (goto-char (point-min))
        (diff-mode)))))

(defmacro stgit-define-diff (name diff-arg &optional unmerged-action)
  `(defun ,name (&optional ignore-whitespace)
     ,(format "Show the patch on the current line.

%sWith a prefix argument, ignore whitespace. With a prefix argument
greater than four (e.g., \\[universal-argument] \
\\[universal-argument] \\[%s]), ignore all whitespace."
              (if unmerged-action
                  (format "For unmerged files, %s.\n\n" unmerged-action)
                "")
              name)
     (interactive "p")
     (stgit-assert-mode)
     (stgit-show-patch ,diff-arg ignore-whitespace)))

(stgit-define-diff stgit-diff
                   "--ours" nil)
(stgit-define-diff stgit-diff-ours
                   "--ours"
                   "diff against our branch")
(stgit-define-diff stgit-diff-theirs
                   "--theirs"
                   "diff against their branch")
(stgit-define-diff stgit-diff-base
                   "--base"
                   "diff against the merge base")
(stgit-define-diff stgit-diff-combined
                   "--cc"
                   "show a combined diff")

(defun stgit-diff-range (&optional ignore-whitespace)
  "Show diff for the range of patches between point and the marked patch.

With a prefix argument, ignore whitespace. With a prefix argument
greater than four (e.g., \\[universal-argument] \
\\[universal-argument] \\[stgit-diff-range]), ignore all whitespace."
  (interactive "p")
  (stgit-assert-mode)
  (unless (= (length stgit-marked-patches) 1)
    (error "Need exactly one patch marked"))
  (let* ((patches (stgit-sort-patches (cons (stgit-patch-name-at-point t t)
                                            stgit-marked-patches)
                                      t))
         (first-patch (car patches))
         (second-patch (if (cdr patches) (cadr patches) first-patch))
         (whitespace-arg (stgit-whitespace-diff-arg ignore-whitespace))
         (applied (stgit-applied-patchsyms t)))
    (unless (and (memq first-patch applied) (memq second-patch applied))
      (error "Can only show diff range for applied patches"))
    (stgit-capture-output (format "*StGit diff %s..%s*"
                                  first-patch second-patch)
      (apply 'stgit-run-git (append '("diff" "--patch-with-stat")
                                    (and whitespace-arg (list whitespace-arg))
                                    (list (format "%s^" (stgit-id first-patch))
                                          (stgit-id second-patch))))
      (with-current-buffer standard-output
        (goto-char (point-min))
        (diff-mode)))))

(defun stgit-move-change-to-index (file &optional force)
  "Copies the work tree state of FILE to index, using git add or git rm.

If FORCE is not nil, use --force."
  (let ((op (if (or (file-exists-p file) (file-symlink-p file))
                '("add") '("rm" "-q"))))
    (stgit-capture-output "*git output*"
      (apply 'stgit-run-git (append op (and force '("--force"))
                                    '("--") (list file))))))

(defun stgit-remove-change-from-index (file)
  "Unstages the change in FILE from the index"
  (stgit-capture-output "*git output*"
    (stgit-run-git "reset" "-q" "--" file)))

(defun stgit-git-index-unmerged-p ()
  (let (result)
    (with-output-to-string
      (setq result (not (zerop (stgit-run-git-silent "diff-index" "--cached"
                                                     "--diff-filter=U"
                                                     "--quiet" "HEAD")))))
    result))

(defun stgit-file-toggle-index ()
  "Move modified file in or out of the index.

Leaves the point where it is, but moves the mark to where the
file ended up. You can then jump to the file with \
\\[exchange-point-and-mark]."
  (interactive)
  (stgit-assert-mode)
  (let* ((patched-file   (or (stgit-patched-file-at-point)
                             (error "No file on the current line")))
         (patched-status (stgit-file->status patched-file)))
    (when (eq patched-status 'unmerged)
      (error (substitute-command-keys "Use \\[stgit-resolve-file] to move an unmerged file to the index")))
    (let* ((patch      (stgit-patch-at-point))
           (patch-name (stgit-patch->name patch))
           (mark-file  (if (eq patched-status 'rename)
                           (stgit-file->cr-to patched-file)
                         (stgit-file->file patched-file)))
           (point-file  (if (eq patched-status 'rename)
                            (stgit-file->cr-from patched-file)
                          (stgit-neighbour-file))))

      (cond ((eq patch-name :work)
             (stgit-move-change-to-index (stgit-file->file patched-file)
                                         (eq patched-status 'ignore)))
            ((eq patch-name :index)
             (stgit-remove-change-from-index (stgit-file->file patched-file)))
            (t
             (error "Can only move files between working tree and index")))
      (stgit-refresh-worktree)
      (stgit-refresh-index)
      (stgit-goto-patch (if (eq patch-name :index) :work :index) mark-file)
      (push-mark nil t t)
      (stgit-goto-patch patch-name point-file))))

(defun stgit-toggle-index ()
  "Move change in or out of the index.

Works on index and work tree, as well as files in either.

Leaves the point where it is, but moves the mark to where the
file ended up. You can then jump to the file with \
\\[exchange-point-and-mark]."
  (interactive)
  (stgit-assert-mode)
  (if (stgit-patched-file-at-point)
      (stgit-file-toggle-index)
    (let ((patch-name (stgit-patch-name-at-point)))
      (unless (memq patch-name '(:index :work))
        (error "Can only move changes between working tree and index"))
      (when (stgit-git-index-unmerged-p)
        (error "Resolve unmerged changes with \\[stgit-resolve-file] first"))
      (if (if (eq patch-name :index)
              (stgit-index-empty-p)
            (stgit-work-tree-empty-p))
          (message "No changes to be moved")
        (stgit-capture-output nil
          (if (eq patch-name :work)
              (stgit-run-git "add" "--update")
            (stgit-run-git "reset" "--mixed" "-q")))
        (stgit-refresh-worktree)
        (stgit-refresh-index))
      (stgit-goto-patch (if (eq patch-name :index) :work :index)))))

(defun stgit-edit ()
  "Edit the patch on the current line."
  (interactive)
  (stgit-assert-mode)
  (let ((patchsym (stgit-patch-name-at-point t t))
        (edit-buf (get-buffer-create "*StGit edit*"))
        (dir default-directory))
    (log-edit 'stgit-confirm-edit t nil edit-buf)
    (set (make-local-variable 'stgit-edit-patchsym) patchsym)
    (setq default-directory dir)
    (let ((standard-output edit-buf))
      (save-excursion
        (stgit-run-silent "edit" "--save-template=-" patchsym)))))

(defun stgit-confirm-edit ()
  (interactive)
  (let ((file (make-temp-file "stgit-edit-")))
    (write-region (point-min) (point-max) file)
    (stgit-capture-output nil
      (stgit-run "edit" "-f" file stgit-edit-patchsym))
    (with-current-buffer log-edit-parent-buffer
      (stgit-reload))))

(defun stgit-new (add-sign &optional refresh)
  "Create a new patch.
With a prefix argument, include a \"Signed-off-by:\" line at the
end of the patch."
  (interactive "P")
  (stgit-assert-mode)
  (let ((edit-buf (get-buffer-create "*StGit edit*"))
        (dir default-directory))
    (log-edit 'stgit-confirm-new t nil edit-buf)
    (setq default-directory dir)
    (set (make-local-variable 'stgit-refresh-after-new) refresh)
    (when add-sign
      (save-excursion
        (let ((standard-output (current-buffer)))
          (stgit-run-silent "new" "--sign" "--save-template=-"))))))

(defun stgit-confirm-new ()
  (interactive)
  (let ((file (make-temp-file "stgit-edit-"))
        (refresh stgit-refresh-after-new))
    (write-region (point-min) (point-max) file)
    (stgit-capture-output nil
      (stgit-run "new" "-f" file))
    (with-current-buffer log-edit-parent-buffer
      (if refresh
          (stgit-refresh)
        (stgit-reload)))))

(defun stgit-new-and-refresh (add-sign)
  "Create a new patch and refresh it with the current changes.

With a prefix argument, include a \"Signed-off-by:\" line at the
end of the patch.

This works just like running `stgit-new' followed by `stgit-refresh'."
  (interactive "P")
  (stgit-assert-mode)
  (stgit-new add-sign t))

(defun stgit-create-patch-name (description)
  "Create a patch name from a long description"
  (let ((patch ""))
    (while (> (length description) 0)
      (cond ((string-match "\\`[a-zA-Z_-]+" description)
             (setq patch (downcase (concat patch
                                           (match-string 0 description))))
             (setq description (substring description (match-end 0))))
            ((string-match "\\` +" description)
             (setq patch (concat patch "-"))
             (setq description (substring description (match-end 0))))
            ((string-match "\\`[^a-zA-Z_-]+" description)
             (setq description (substring description (match-end 0))))))
    (cond ((= (length patch) 0)
           "patch")
          ((> (length patch) 20)
           (substring patch 0 20))
          (t patch))))

(defun stgit-delete (patchsyms &optional spill-p)
  "Delete the patches in PATCHSYMS.
Interactively, delete the marked patches, or the patch at point.

With a prefix argument, or SPILL-P, spill the patch contents to
the work tree and index."
  (interactive (list (stgit-patches-marked-or-at-point t t)
                     current-prefix-arg))
  (stgit-assert-mode)
  (unless patchsyms
    (error "No patches to delete"))
  (when (memq :index patchsyms)
    (error "Cannot delete the index"))
  (when (memq :work  patchsyms)
    (error "Cannot delete the work tree"))

  (let ((npatches (length patchsyms)))
    (when (yes-or-no-p (format "Really delete %d patch%s%s? "
                               npatches
                               (if (= 1 npatches) "" "es")
                               (if spill-p
                                   " (spilling contents to index)"
                                 "")))
      (let ((args (if spill-p 
                      (cons "--spill" patchsyms)
                    patchsyms)))
        (stgit-capture-output nil
          (apply 'stgit-run "delete" args))
        (stgit-reload)))))

(defun stgit-move-patches-target ()
  "Return the patchsym indicating a target patch for
`stgit-move-patches'.

This is either the first unmarked patch at or after point, or one
of :top and :bottom if the point is after or before the applied
patches."

  (save-excursion
    (let (result)
      (while (not result)
        (let ((patchsym (stgit-patch-name-at-point)))
          (cond ((memq patchsym '(:work :index)) (setq result :top))
                (patchsym (if (memq patchsym stgit-marked-patches)
                              (stgit-next-patch)
                            (setq result patchsym)))
                ((re-search-backward "^>" nil t) (setq result :top))
                (t (setq result :bottom)))))
      result)))

(defun stgit-sort-patches (patchsyms &optional allow-duplicates)
  "Returns the list of patches in PATCHSYMS sorted according to
their position in the patch series, bottommost first.

PATCHSYMS must not contain duplicate entries, unless
ALLOW-DUPLICATES is not nil."
  (let (sorted-patchsyms
        (series (with-output-to-string
                  (with-current-buffer standard-output
                    (stgit-run-silent "series" "--noprefix"))))
        start)
    (while (string-match "^\\(.+\\)" series start)
      (let ((patchsym (intern (match-string 1 series))))
        (when (memq patchsym patchsyms)
          (setq sorted-patchsyms (cons patchsym sorted-patchsyms))))
      (setq start (match-end 0)))
    (setq sorted-patchsyms (nreverse sorted-patchsyms))

    (unless allow-duplicates
      (unless (= (length patchsyms) (length sorted-patchsyms))
        (error "Internal error")))

    sorted-patchsyms))

(defun stgit-move-patches (patchsyms target-patch)
  "Move the patches in PATCHSYMS to below TARGET-PATCH.
If TARGET-PATCH is :bottom or :top, move the patches to the
bottom or top of the stack, respectively.

Interactively, move the marked patches to where the point is."
  (interactive (list stgit-marked-patches
                     (stgit-move-patches-target)))
  (stgit-assert-mode)
  (unless patchsyms
    (error "Need at least one patch to move"))

  (unless target-patch
    (error "Point not at a patch"))

  ;; need to have patchsyms sorted by position in the stack
  (let ((sorted-patchsyms (stgit-sort-patches patchsyms)))
    (stgit-capture-output nil
      (if (eq target-patch :top)
          (apply 'stgit-run "float" sorted-patchsyms)
        (apply 'stgit-run
               "sink"
               (append (unless (eq target-patch :bottom)
                         (list "--to" target-patch))
                       '("--")
                       sorted-patchsyms)))))
  (stgit-reload))

(defun stgit-squash (patchsyms)
  "Squash the patches in PATCHSYMS.
Interactively, squash the marked patches.

Unless there are any conflicts, the patches will be merged into
one patch, which will occupy the same spot in the series as the
deepest patch had before the squash."
  (interactive (list stgit-marked-patches))
  (stgit-assert-mode)
  (when (< (length patchsyms) 2)
    (error "Need at least two patches to squash"))
  (let ((stgit-buffer (current-buffer))
        (edit-buf (get-buffer-create "*StGit edit*"))
        (dir default-directory)
        (sorted-patchsyms (stgit-sort-patches patchsyms)))
    (log-edit 'stgit-confirm-squash t nil edit-buf)
    (set (make-local-variable 'stgit-patchsyms) sorted-patchsyms)
    (setq default-directory dir)
    (let ((result (let ((standard-output edit-buf))
                    (save-excursion
                      (apply 'stgit-run-silent "squash"
                             "--save-template=-" sorted-patchsyms)))))

      ;; stg squash may have reordered the patches or caused conflicts
      (with-current-buffer stgit-buffer
        (stgit-reload))

      (unless (eq 0 result)
        (fundamental-mode)
        (rename-buffer "*StGit error*")
        (resize-temp-buffer-window)
        (switch-to-buffer-other-window stgit-buffer)
        (error "stg squash failed")))))

(defun stgit-confirm-squash ()
  (interactive)
  (let ((file (make-temp-file "stgit-edit-")))
    (write-region (point-min) (point-max) file)
    (stgit-capture-output nil
      (apply 'stgit-run "squash" "-f" file stgit-patchsyms))
    (with-current-buffer log-edit-parent-buffer
      (stgit-clear-marks)
      ;; Go to first marked patch and stay there
      (goto-char (point-min))
      (re-search-forward (concat "^[>+-]\\*") nil t)
      (move-to-column goal-column)
      (let ((pos (point)))
        (stgit-reload)
        (goto-char pos)))))

(defun stgit-help ()
  "Display help for the StGit mode."
  (interactive)
  (describe-function 'stgit-mode))

(defun stgit-undo-or-redo (redo hard)
  "Run stg undo or, if REDO is non-nil, stg redo.

If HARD is non-nil, use the --hard flag."
  (stgit-assert-mode)
  (let ((cmd (if redo "redo" "undo")))
    (stgit-capture-output nil
      (if arg
          (when (or (and (stgit-index-empty-p)
                         (stgit-work-tree-empty-p))
                    (y-or-n-p (format "Hard %s may overwrite index/work tree changes. Continue? "
                                      cmd)))
            (stgit-run cmd "--hard"))
        (stgit-run cmd))))
  (stgit-reload))

(defun stgit-undo (&optional arg)
  "Run stg undo.
With prefix argument, run it with the --hard flag.

See also `stgit-redo'."
  (interactive "P")
  (stgit-undo-or-redo nil arg))

(defun stgit-redo (&optional arg)
  "Run stg redo.
With prefix argument, run it with the --hard flag.

See also `stgit-undo'."
  (interactive "P")
  (stgit-undo-or-redo t arg))

(defun stgit-refresh (&optional arg)
  "Run stg refresh.
If the index contains any changes, only refresh from index.

With prefix argument, refresh the marked patch or the patch under point."
  (interactive "P")
  (stgit-assert-mode)
  (let ((patchargs (if arg
                       (let ((patches (stgit-patches-marked-or-at-point nil t)))
                         (when (> (length patches) 1)
                           (error "Too many patches marked"))
                         (cons "-p" patches))
                     nil)))
    (unless (stgit-index-empty-p)
      (setq patchargs (cons "--index" patchargs)))
    (stgit-capture-output nil
      (apply 'stgit-run "refresh" patchargs))
    (stgit-refresh-git-status))
  (stgit-reload))

(defvar stgit-show-worktree nil
  "If nil, inhibit showing work tree and index in the stgit buffer.

See also `stgit-show-worktree-mode'.")

(defvar stgit-show-ignored nil
  "If nil, inhibit showing files ignored by git.")

(defvar stgit-show-unknown nil
  "If nil, inhibit showing files not registered with git.")

(defvar stgit-show-patch-names t
  "If nil, inhibit showing patch names.")

(defun stgit-toggle-worktree (&optional arg)
  "Toggle the visibility of the work tree.
With ARG, show the work tree if ARG is positive.

Its initial setting is controlled by `stgit-default-show-worktree'.

`stgit-show-worktree-mode' controls where on screen the index and
work tree will show up."
  (interactive)
  (stgit-assert-mode)
  (setq stgit-show-worktree
        (if (numberp arg)
            (> arg 0)
          (not stgit-show-worktree)))
  (stgit-reload))

(defun stgit-toggle-ignored (&optional arg)
  "Toggle the visibility of files ignored by git in the work
tree. With ARG, show these files if ARG is positive.

Use \\[stgit-toggle-worktree] to show the work tree."
  (interactive)
  (stgit-assert-mode)
  (setq stgit-show-ignored
        (if (numberp arg)
            (> arg 0)
          (not stgit-show-ignored)))
  (stgit-reload))

(defun stgit-toggle-unknown (&optional arg)
  "Toggle the visibility of files not registered with git in the
work tree. With ARG, show these files if ARG is positive.

Use \\[stgit-toggle-worktree] to show the work tree."
  (interactive)
  (stgit-assert-mode)
  (setq stgit-show-unknown
        (if (numberp arg)
            (> arg 0)
          (not stgit-show-unknown)))
  (stgit-reload))

(defun stgit-toggle-patch-names (&optional arg)
  "Toggle the visibility of patch names. With ARG, show patch names
if ARG is positive.

The initial setting is controlled by `stgit-default-show-patch-names'."
  (interactive)
  (stgit-assert-mode)
  (setq stgit-show-patch-names
        (if (numberp arg)
            (> arg 0)
          (not stgit-show-patch-names)))
  (stgit-reload))

(provide 'stgit)