[Emacs-diffs] /srv/bzr/emacs/trunk r102709: * admin/bzrmerge.el: New file to help merge branches while skipping

[Stefan Monnier]

------------------------------------------------------------
revno: 102709
committer: Stefan Monnier <address@hidden>
branch nick: trunk
timestamp: Sun 2010-12-26 20:27:08 -0500
message:
  * admin/bzrmerge.el: New file to help merge branches while skipping
  some revisions (e.g. from emacs-23 to trunk).
added:
  admin/bzrmerge.el
modified:
  admin/ChangeLog

=== modified file 'admin/ChangeLog'
--- a/admin/ChangeLog   2010-12-03 22:08:05 +0000
+++ b/admin/ChangeLog   2010-12-27 01:27:08 +0000
@@ -1,3 +1,8 @@
+2010-12-27  Stefan Monnier  <address@hidden>
+
+       * bzrmerge.el: New file to help merge branches while skipping
+       some revisions (e.g. from emacs-23 to trunk).
+
 2010-12-03  Andreas Schwab  <address@hidden>
 
        * CPP-DEFINES (EXPLICIT_SIGN_EXTEND): Remove.

=== added file 'admin/bzrmerge.el'
--- a/admin/bzrmerge.el 1970-01-01 00:00:00 +0000
+++ b/admin/bzrmerge.el 2010-12-27 01:27:08 +0000
@@ -0,0 +1,296 @@
+;;; bzrmerge.el --- 
+
+;; Copyright (C) 2010  Stefan Monnier
+
+;; Author: Stefan Monnier <address@hidden>
+;; Keywords: 
+
+;; This program is free software; you can redistribute it and/or modify
+;; it under the terms of the GNU General Public License as published by
+;; the Free Software Foundation, either version 3 of the License, or
+;; (at your option) any later version.
+
+;; This program 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
+;; along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+;;; Commentary:
+
+;; 
+
+;;; Code:
+
+(defun bzrmerge-merges ()
+  "Return the list of already merged (not not committed) revisions.
+The list returned is sorted by oldest-first."
+  (with-current-buffer (get-buffer-create "*bzrmerge*")
+    (erase-buffer)
+    ;; We generally want to make sure we start with a clean tree, but we also
+    ;; want to allow restarts (i.e. with some part of FROM already merged but
+    ;; not yet committed).
+    (call-process "bzr" nil t nil "status" "-v")
+    (goto-char (point-min))
+    (when (re-search-forward "^conflicts:\n" nil t)
+      (error "You still have unresolved conflicts"))
+    (let ((merges ()))
+      (if (not (re-search-forward "^pending merges:\n" nil t))
+          (when (save-excursion
+                  (goto-char (point-min))
+                  (re-search-forward "^[a-z ]*:\n" nil t))
+            (error "You still have uncommitted changes"))
+        ;; This is really stupid, but it seems there's no easy way to figure
+        ;; out which revisions have been merged already.  The only info I can
+        ;; find is the "pending merges" from "bzr status -v", which is not
+        ;; very machine-friendly.
+        (while (not (eobp))
+          (skip-chars-forward " ")
+          (push (buffer-substring (point) (line-end-position)) merges)
+          (forward-line 1)))
+      merges)))
+
+(defun bzrmerge-check-match (merge)
+  ;; Make sure the MERGES match the revisions on the FROM branch.
+  ;; Stupidly the best form of MERGES I can find is the one from
+  ;; "bzr status -v" which is very machine non-friendly, so I have
+  ;; to do some fuzzy matching.
+  (let ((author
+         (or
+          (save-excursion
+            (if (re-search-forward "^author: *\\([^<]*[^ ]\\) +<.*"
+                                   nil t)
+                (match-string 1)))
+          (save-excursion
+            (if (re-search-forward
+                 "^committer: *\\([^<]*[^< ]\\) +<" nil t)
+                (match-string 1)))))
+        (timestamp
+         (save-excursion
+           (if (re-search-forward
+                "^timestamp:[^0-9]*\\([-0-9]+\\)" nil t)
+               (match-string 1))))
+        (line1
+         (save-excursion
+           (if (re-search-forward "^message:[ \n]*" nil t)
+               (buffer-substring (point) (line-end-position))))))
+    ;; The `merge' may have a truncated line1 with "...", so get
+    ;; rid of any "..." and then look for a prefix match.
+    (when (string-match "\\.+\\'" merge)
+      (setq merge (substring merge 0 (match-beginning 0))))
+    (or (string-prefix-p
+         merge (concat author " " timestamp " " line1))
+        (string-prefix-p
+         merge (concat author " " timestamp " [merge] " line1)))))
+
+(defun bzrmerge-missing (from merges)
+  "Return the list of revisions that need to be merged.
+MERGES is the revisions already merged but not yet committed.
+The result is of the form (TOMERGE . TOSKIP) where TOMERGE and TOSKIP
+are both lists of revnos, in oldest-first order."
+  (with-current-buffer (get-buffer-create "*bzrmerge*")
+    (erase-buffer)
+    (call-process "bzr" nil t nil "missing" "--theirs-only"
+                  (expand-file-name from))
+    (let ((revnos ()) (skipped ()))
+      (pop-to-buffer (current-buffer))
+      (goto-char (point-max))
+      (while (re-search-backward 
"^------------------------------------------------------------\nrevno: 
\\([0-9.]+\\).*" nil t)
+        (save-excursion
+          (if merges
+              (while (not (bzrmerge-check-match (pop merges)))
+                (unless merges
+                  (error "Unmatched tip of merged revisions")))
+            (let ((case-fold-search t)
+                  (revno (match-string 1))
+                  (skip nil))
+              (if (string-match "\\." revno)
+                  (error "Unexpected dotted revno!")
+                (setq revno (string-to-number revno)))
+              (re-search-forward "^message:\n")
+              (while (and (not skip)
+                          (re-search-forward
+                           "back[- ]?port\\|merge\\|re-?generate\\|bump 
version" nil t))
+                (let ((str (buffer-substring (line-beginning-position)
+                                             (line-end-position))))
+                  (when (string-match "\\` *" str)
+                    (setq str (substring str (match-end 0))))
+                  (when (string-match "[.!;, ]+\\'" str)
+                    (setq str (substring str 0 (match-beginning 0))))
+                  (if (save-excursion (y-or-n-p (concat str ": Skip? ")))
+                      (setq skip t))))
+              (if skip
+                  (push revno skipped)
+                (push revno revnos)))))
+        (delete-region (point) (point-max)))
+      (cons (nreverse revnos) (nreverse skipped)))))
+
+(defun bzrmerge-resolve (file)
+  (unless (file-exists-p file) (error "Bzrmerge-resolve: Can't find %s" file))
+  (with-demoted-errors
+    (let ((exists (find-buffer-visiting file)))
+      (with-current-buffer (find-file-noselect file)
+        (if (buffer-modified-p)
+            (error "Unsaved changes in %s" (current-buffer)))
+        (save-excursion
+          (cond
+           ((derived-mode-p 'change-log-mode)
+            ;; Fix up dates before resolving the conflicts.
+            (goto-char (point-min))
+            (let ((diff-auto-refine-mode nil))
+              (while (re-search-forward smerge-begin-re nil t)
+                (smerge-match-conflict)
+                (smerge-ensure-match 3)
+                (let ((start1 (match-beginning 1))
+                      (end1 (match-end 1))
+                      (start3 (match-beginning 3))
+                      (end3 (copy-marker (match-end 3) t)))
+                  (goto-char start3)
+                  (while (re-search-forward change-log-start-entry-re end3 t)
+                    (let* ((str (match-string 0))
+                           (newstr (save-match-data
+                                     (concat (add-log-iso8601-time-string)
+                                             (when (string-match " *\\'" str)
+                                               (match-string 0 str))))))
+                      (replace-match newstr t t)))
+                  ;; change-log-resolve-conflict prefers to put match-1's
+                  ;; elements first (for equal dates), whereas we want to put
+                  ;; match-3's first.
+                  (let ((match3 (buffer-substring start3 end3))
+                        (match1 (buffer-substring start1 end1)))
+                    (delete-region start3 end3)
+                    (goto-char start3)
+                    (insert match1)
+                    (delete-region start1 end1)
+                    (goto-char start1)
+                    (insert match3)))))
+            ;; (pop-to-buffer (current-buffer)) (debug 'before-resolve)
+            ))
+          ;; Try to resolve the conflicts.
+          (cond
+           ((member file '("configure" "lisp/ldefs-boot.el"))
+            (call-process "bzr" nil t nil "revert" file)
+            (revert-buffer nil 'noconfirm))
+           (t
+            (goto-char (point-max))
+            (while (re-search-backward smerge-begin-re nil t)
+              (save-excursion
+                (ignore-errors
+                  (smerge-match-conflict)
+                  (smerge-resolve))))
+            ;; (when (derived-mode-p 'change-log-mode)
+            ;;   (pop-to-buffer (current-buffer)) (debug 'after-resolve))
+            (save-buffer)))
+          (goto-char (point-min))
+          (prog1 (re-search-forward smerge-begin-re nil t)
+            (unless exists (kill-buffer))))))))
+
+(defun bzrmerge-add-metadata (from endrevno)
+  "Add the metadata for a merge of FROM upto ENDREVNO.
+Does not make other difference."
+  (if (with-temp-buffer
+        (call-process "bzr" nil t nil "status")
+        (goto-char (point-min))
+        (re-search-forward "^conflicts:\n" nil t))
+      (error "Don't know how to add metadata in the presence of conflicts")
+    (call-process "bzr" nil t nil "shelve" "--all"
+                  "-m" "Bzrmerge shelved merge during skipping")
+    (call-process "bzr" nil t nil "revert")
+    (call-process "bzr" nil t nil
+                  "merge" "-r" (format "%s" endrevno) from)
+    (call-process "bzr" nil t nil "revert" ".")
+    (call-process "bzr" nil t nil "unshelve")))
+  
+(defvar bzrmerge-already-done nil)
+
+(defun bzrmerge-apply (missing from)
+  (setq from (expand-file-name from))
+  (with-current-buffer (get-buffer-create "*bzrmerge*")
+    (erase-buffer)
+    (when (equal (cdr bzrmerge-already-done) (list from missing))
+      (setq missing (car bzrmerge-already-done)))
+    (setq bzrmerge-already-done nil)
+    (let ((merge (car missing))
+          (skip (cdr missing))
+          beg end)
+      (when (or merge skip)
+        (cond
+         ((and skip (or (null merge) (< (car skip) (car merge))))
+          ;; Do a "skip" (i.e. merge the meta-data only).
+          (setq beg (1- (car skip)))
+          (while (and skip (or (null merge) (< (car skip) (car merge))))
+            (assert (> (car skip) (or end beg)))
+            (setq end (pop skip)))
+          (message "Skipping %s..%s" beg end)
+          (bzrmerge-add-metadata from end))
+
+         (t
+          ;; Do a "normal" merge.
+          (assert (or (null skip) (< (car merge) (car skip))))
+          (setq beg (1- (car merge)))
+          (while (and merge (or (null skip) (< (car merge) (car skip))))
+            (assert (> (car merge) (or end beg)))
+            (setq end (pop merge)))
+          (message "Merging %s..%s" beg end)
+          (if (with-temp-buffer
+                (call-process "bzr" nil t nil "status")
+                (zerop (buffer-size)))
+              (call-process "bzr" nil t nil
+                            "merge" "-r" (format "%s" end) from)
+            ;; Stupidly, "bzr merge --force -r A..B" dos not maintain the
+            ;; metadata properly except when the checkout is clean.
+            (call-process "bzr" nil t nil "merge"
+                          "--force" "-r" (format "%s..%s" beg end) from)
+            ;; The merge did not update the metadata, so force the next time
+            ;; around to update it (as a "skip").
+            (push end skip))
+          (pop-to-buffer (current-buffer))
+          (sit-for 1)
+          ;; (debug 'after-merge)
+          ;; Check the conflicts.
+          (let ((conflicted nil)
+                (files ()))
+            (goto-char (point-min))
+            (when (re-search-forward "bzr: ERROR:" nil t)
+              (error "Internal Bazaar error!!"))
+            (while (re-search-forward "^Text conflict in " nil t)
+              (push (buffer-substring (point) (line-end-position)) files))
+            (if (re-search-forward "^\\([0-9]+\\) conflicts encountered" nil t)
+                (if (/= (length files) (string-to-number (match-string 1)))
+                    (setq conflicted t))
+              (if files (setq conflicted t)))
+            (dolist (file files)
+              (if (bzrmerge-resolve file)
+                  (setq conflicted t)))
+            (when conflicted
+              (setq bzrmerge-already-done
+                    (list (cons merge skip) from missing))
+              (error "Resolve conflicts manually")))))
+        (cons merge skip)))))
+
+(defun bzrmerge (from)
+  "Merge from branch FROM into `default-directory'."
+  (interactive
+   (list
+    (let ((def
+           (with-temp-buffer
+             (call-process "bzr" nil t nil "info")
+             (goto-char (point-min))
+             (when (re-search-forward "submit branch: *" nil t)
+               (buffer-substring (point) (line-end-position))))))
+      (read-file-name "From branch: " nil nil nil def))))
+  (message "Merging from %s..." from)
+  (require 'vc-bzr)
+  (let ((default-directory (or (vc-bzr-root default-directory)
+                               (error "Not in a Bzr tree"))))
+    ;; First, check the status.
+    (let* ((merges (bzrmerge-merges))
+           ;; OK, we have the status, now check the missing data.
+           (missing (bzrmerge-missing from merges)))
+      (while missing
+        (setq missing (bzrmerge-apply missing from))))))
+
+(provide 'bzrmerge)
+;;; bzrmerge.el ends here