Support git commit --amend/--signoff

* lisp/vc/log-edit.el (log-edit-font-lock-keywords): Allow hyphens in
header names.
(log-edit-toggle-header): New function.
(log-edit-extract-headers): Accept function values in HEADERS alist.

* lisp/vc/vc-git.el (vc-git-log-edit-toggle-signoff): New function.
(vc-git-log-edit-toggle-amend): New function.
(vc-git-log-edit-toggle-signoff): New function.
(vc-git-log-edit-mode): New major mode.
(vc-git-log-edit-mode-map): Keymap for it.
(vc-git-checkin): Handle "Amend" and "Sign-Off" headers.

1 files changed, 41 insertions, 9 deletions

diff --git a/lisp/vc/log-edit.el b/lisp/vc/log-edit.el
index 932abb9818c..3c34a762a1b 100644
--- a/lisp/vc/log-edit.el
+++ b/lisp/vc/log-edit.el
@@ -341,7 +341,7 @@ automatically."
 (defvar log-edit-font-lock-keywords
   ;; Copied/inspired by message-font-lock-keywords.
   `((log-edit-match-to-eoh
-     (,(concat "^\\(\\([[:alpha:]]+\\):\\)" log-edit-header-contents-regexp)
+     (,(concat "^\\(\\([[:alpha:]-]+\\):\\)" log-edit-header-contents-regexp)
       (progn (goto-char (match-beginning 0)) (match-end 0)) nil
       (1 (if (assoc-string (match-string 2) log-edit-headers-alist t)
              'log-edit-header
@@ -900,14 +900,44 @@ Rename relative filenames in the ChangeLog entry as FILES."
       (insert "\n"))
     log-edit-author))
 
+(defun log-edit-toggle-header (header value)
+  "Toggle a boolean-type header in the current buffer.
+If the value of HEADER is VALUE, clear it.  Otherwise, add the
+header if it's not present and set it to VALUE.  Then make sure
+there is an empty line after the headers.  Return t if toggled
+on, otherwise nil."
+  (let ((val t)
+        (line (concat header ": " value "\n")))
+    (save-excursion
+      (save-restriction
+        (rfc822-goto-eoh)
+        (narrow-to-region (point-min) (point))
+        (goto-char (point-min))
+        (if (re-search-forward (concat "^" header ":"
+                                       log-edit-header-contents-regexp)
+                               nil t)
+            (if (setq val (not (string= (match-string 1) value)))
+                (replace-match line t t)
+              (replace-match "" t t nil 1))
+          (insert line)))
+      (rfc822-goto-eoh)
+      (delete-horizontal-space)
+      (unless (looking-at "\n")
+        (insert "\n")))
+    val))
+
 (defun log-edit-extract-headers (headers comment)
   "Extract headers from COMMENT to form command line arguments.
-HEADERS should be an alist with elements of the form (HEADER . CMDARG)
-associating header names to the corresponding cmdline option name and the
-result is then a list of the form (MSG CMDARG1 HDRTEXT1 CMDARG2 HDRTEXT2...).
-where MSG is the remaining text from STRING.
-If \"Summary\" is not in HEADERS, then the \"Summary\" header is extracted
-anyway and put back as the first line of MSG."
+HEADERS should be an alist with elements (HEADER . CMDARG)
+or (HEADER . FUNCTION) associating headers to command line
+options and the result is then a list of the form (MSG ARGUMENTS...)
+where MSG is the remaining text from COMMENT.
+FUNCTION should be a function of one argument that takes the
+header value and returns the list of strings to be appended to
+ARGUMENTS.  CMDARG will be added to ARGUMENTS followed by the
+header value.  If \"Summary\" is not in HEADERS, then the
+\"Summary\" header is extracted anyway and put back as the first
+line of MSG."
   (with-temp-buffer
     (insert comment)
     (rfc822-goto-eoh)
@@ -923,8 +953,10 @@ anyway and put back as the first line of MSG."
                                   nil t)
           (if (eq t (cdr header))
               (setq summary (match-string 1))
-            (push (match-string 1) res)
-            (push (or (cdr header) (car header)) res))
+            (if (functionp (cdr header))
+                (setq res (nconc res (funcall (cdr header) (match-string 1))))
+              (push (match-string 1) res)
+              (push (or (cdr header) (car header)) res)))
           (replace-match "" t t)))
       ;; Remove header separator if the header is empty.
       (widen)