bug#29366: gitmerge to handle NEWS better

[Glenn Morris <rgm@gnu.org>]

David Engster wrote:

> I'm not sure about that smerge stuff either, that was something I took
> over from bzrmerge. It may be that it is not functional. I hope I can
> make time to take a look at this in the coming days.

Thanks! Here's my revised patch for this. It just does a commit after a
successful auto-conflict resolution. It seems to work...

--- a/admin/gitmerge.el
+++ b/admin/gitmerge.el
@@ -316,11 +316,7 @@ gitmerge-resolve
                                    (gitmerge-emacs-version gitmerge--from))))
                    (file-exists-p temp)
                    (or noninteractive
-                       (and
-                        (y-or-n-p "Try to fix NEWS conflict? ")
-                        ;; FIXME
-                        (y-or-n-p "This is buggy, really try? ")
-                        )))
+                       (y-or-n-p "Try to fix NEWS conflict? ")))
               (let ((relfile (file-name-nondirectory file))
                     (tempfile (make-temp-file "gitmerge")))
                 (unwind-protect
@@ -431,7 +427,9 @@ gitmerge-resolve-unmerged
 	      (setq conflicted t)
 	    ;; Mark as resolved
 	    (call-process "git" nil t nil "add" file)))
-	(when conflicted
+	(if (not conflicted)
+	    (and files (not (gitmerge-commit))
+		 (error "Error committing resolution - fix it manually"))
 	  (with-current-buffer (get-buffer-create gitmerge-warning-buffer)
 	    (erase-buffer)
 	    (insert "For the following files, conflicts could\n"
@@ -457,6 +455,12 @@ gitmerge-repo-clean
 		    "diff" "--name-only")
       (zerop (buffer-size))))
 
+(defun gitmerge-commit ()
+  "Commit, and return non-nil if it succeeds."
+  (with-current-buffer (get-buffer-create gitmerge-output-buffer)
+    (erase-buffer)
+    (eq 0 (call-process "git" nil t nil "commit" "--no-edit"))))
+
 (defun gitmerge-maybe-resume ()
   "Check if we have to resume a merge.
 If so, add no longer conflicted files and commit."
@@ -478,11 +482,8 @@ gitmerge-maybe-resume
 	(gitmerge-resolve-unmerged)
 	;; Commit the merge.
 	(when mergehead
-	  (with-current-buffer (get-buffer-create gitmerge-output-buffer)
-	    (erase-buffer)
-	    (unless (zerop (call-process "git" nil t nil
-					 "commit" "--no-edit"))
-	      (error "Git error during merge - fix it manually"))))
+	  (or (gitmerge-commit)
+	      (error "Git error during merge - fix it manually")))
 	;; Successfully resumed.
 	t))))