Subject: bug#33650: closed (Re: bug#33650: 27.0.50; Root diffs between revisions)

From: [email-masked] (GNU bug Tracking System)
Date: Mon, 10 Dec 2018 23:58:04 +0000

Your bug report

#33650: 27.0.50; Root diffs between revisions

which was filed against the emacs package, has been closed.

The explanation is attached below, along with your original report.
If you require more details, please reply to [email-masked].

-- 
33650: http://debbugs.gnu.org/cgi/bugreport.cgi?bug=33650
GNU Bug Tracking System
Contact [email-masked] with problems

Subject: Re: bug#33650: 27.0.50; Root diffs between revisions
From: Juri Linkov <[email-masked]>
To: Eli Zaretskii <[email-masked]>
Cc: [email-masked]
Date: Tue, 11 Dec 2018 01:55:15 +0200
List-Id: <debbugs-submit.debbugs.gnu.org>

>> > Isn't the result user-visible change in behavior?
>>
>> Yes, this fix changes user-visible behavior, so perhaps it should be
>> mentioned in NEWS.
>
> I think so too.
>
>> As "fileset" is essential for `vc-version-diff',
>> "whole tree" is essential for `vc-root-version-diff':
>
> OK, thanks.

Pushed to master and closed.

Subject: 27.0.50; Root diffs between revisions
From: Juri Linkov <[email-masked]>
To: [email-masked]
Date: Thu, 06 Dec 2018 23:54:16 +0200
List-Id: <debbugs-submit.debbugs.gnu.org>

A VC command that still doesn't allow using diff-mode automatically
thus preventing proper fontification and all other related features
is `vc-root-diff' with a prefix argument HISTORIC.  It has such comment:

      ;; FIXME: this does not work right, `vc-version-diff' ends up
      ;; calling `vc-deduce-fileset' to find the files to diff, and
      ;; that's not what we want here, we want the diff for the VC root dir.

This patch fixes this omission by implementing `vc-root-version-diff'
that is able to compare two revisions even on separate branches from
their roots:

diff --git a/lisp/vc/vc.el b/lisp/vc/vc.el
index de43544864..74979e7381 100644
--- a/lisp/vc/vc.el
+++ b/lisp/vc/vc.el
@@ -1827,6 +1827,28 @@ vc-version-diff
   (vc-diff-internal t (vc-deduce-fileset t) rev1 rev2
 		    (called-interactively-p 'interactive)))
 
+;;;###autoload
+(defun vc-root-version-diff (_files rev1 rev2)
+  "Report diffs between revisions of the whole tree in the repository history."
+  (interactive (vc-diff-build-argument-list-internal))
+  ;; This is a mix of `vc-root-diff' and `vc-version-diff'
+  (when (and (not rev1) rev2)
+    (error "Not a valid revision range"))
+  (let ((backend (vc-deduce-backend))
+        (default-directory default-directory)
+        rootdir)
+    (if backend
+	(setq rootdir (vc-call-backend backend 'root default-directory))
+      (setq rootdir (read-directory-name "Directory for VC root-diff: "))
+      (setq backend (vc-responsible-backend rootdir))
+      (if backend
+	  (setq default-directory rootdir)
+	(error "Directory is not version controlled")))
+    (let ((default-directory rootdir))
+      (vc-diff-internal
+       t (list backend (list rootdir)) rev1 rev2
+       (called-interactively-p 'interactive)))))
+
 ;;;###autoload
 (defun vc-diff (&optional historic not-urgent)
   "Display diffs between file revisions.
@@ -1900,10 +1922,8 @@ vc-root-diff
 saving the buffer."
   (interactive (list current-prefix-arg t))
   (if historic
-      ;; FIXME: this does not work right, `vc-version-diff' ends up
-      ;; calling `vc-deduce-fileset' to find the files to diff, and
-      ;; that's not what we want here, we want the diff for the VC root dir.
-      (call-interactively 'vc-version-diff)
+      ;; We want the diff for the VC root dir.
+      (call-interactively 'vc-root-version-diff)
     (when buffer-file-name (vc-buffer-sync not-urgent))
     (let ((backend (vc-deduce-backend))
 	  (default-directory default-directory)