bug#28466: 26.0.50; diff in vc-outgoing doesn't work properly

bug#28466: 26.0.50; diff in vc-outgoing doesn't work properly

[Tom Tromey]

I'm using vc-dir mode.
I used "O" to show the outgoing changes.

In the *vc-outgoing* buffer, I selected the entire buffer
(C-x h) and then typed "=" to make a diff.

I was expecting to see a diff showing the combined contents of all 3 of
my outgoing patches.

However, the generated diff is missing the oldest patch in the series.

Tom



In GNU Emacs 26.0.50 (build 20, x86_64-pc-linux-gnu, GTK+ Version 3.22.17)
 of 2017-09-14 built on bapiya
Repository revision: a7036e04014e5b0548653f26f87ee9e98be05ba3
Windowing system distributor 'Fedora Project', version 11.0.11903000
System Description:	Fedora release 25 (Twenty Five)

Recent messages:
Mark set
Quit [3 times]
Mark activated
next-line: End of buffer
Finding changes in ....
Quit [2 times]
next-line: End of buffer
Mark set
previous-line: Beginning of buffer
Finding changes in ....
scroll-up-command: End of buffer
Configured using:
 'configure --prefix=/home/tromey/Emacs/install'

Configured features:
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LIBSELINUX GNUTLS LIBXML2 FREETYPE M17N_FLT LIBOTF XFT ZLIB
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Important settings:
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Load-path shadows:
/home/tromey/.emacs.d/elpa/bubbles-0.5/bubbles hides /home/tromey/Emacs/install/share/emacs/26.0.50/lisp/play/bubbles

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bug#28466: 26.0.50; diff in vc-outgoing doesn't work properly

[Tom Tromey]

Tom> I was expecting to see a diff showing the combined contents of all 3 of
Tom> my outgoing patches.

Tom> However, the generated diff is missing the oldest patch in the series.

The appended patch fixes this for me.
I'll put it on the Emacs 26 branch after a few days, unless there are
comments.

Tom

diff --git a/lisp/vc/log-view.el b/lisp/vc/log-view.el
index 52f56ed..d6963d0 100644
--- a/lisp/vc/log-view.el
+++ b/lisp/vc/log-view.el
@@ -608,10 +608,16 @@ log-view-diff-changeset
     (log-view-diff-common beg end t)))
 
 (defun log-view-diff-common (beg end &optional whole-changeset)
-  (let ((to (log-view-current-tag beg))
-        (fr (log-view-current-tag end)))
-    (when (string-equal fr to)
-      ;; TO and FR are the same, look at the previous revision.
+  (let* ((to (log-view-current-tag beg))
+         (fr-entry (log-view-current-entry end))
+         (fr (cadr fr-entry)))
+    ;; When TO and FR are the same, or when point is on a line after
+    ;; the last entry, look at the previous revision.
+    (when (or (string-equal fr to)
+              (>= (point)
+                  (save-excursion
+                    (goto-char (car fr-entry))
+                    (forward-line))))
       (setq fr (vc-call-backend log-view-vc-backend 'previous-revision nil fr)))
     (vc-diff-internal
      t (list log-view-vc-backend

bug#28466: 26.0.50; diff in vc-outgoing doesn't work properly

[Dmitry Gutov]

On 9/17/17 12:53 AM, Tom Tromey wrote:

> The appended patch fixes this for me.
> I'll put it on the Emacs 26 branch after a few days, unless there are
> comments.

Makes sense to me, please feel free to commit.

I don't particularly like how the region end is interpreted in this 
command, though. I'd be more comfortable with the semantics of "show the 
contents of all these revisions combined", which means replacing the 
condition with t. Something to think about, for some future version.

bug#28466: doneu

[Tom Tromey]

Fix checked in.

Tom