Subject: bug#17570: * lisp/vc/vc-hg.el (vc-hg-working-revision): Fix returning working revision instead of last revision.

From: Santiago Payà i Miralta <[email-masked]>
Date: Sat, 24 May 2014 00:57:19 +0200

Hi emacs,

I wish to fix the lisp/vc/vc-hg.el (vc-hg-working-revision) function with
the `hg parent' command.

Actually this function uses the `hg log -l 1' command that returns the last
commited revision, not the last checked out revision. When checking out a
specified revision with `hg update REV' the actual revision of FILE is
returned by `hg parent'.

vc.el:
;; * working-revision (file)
;;
;;   Return the working revision of FILE.  This is the revision fetched
;;   by the last checkout or update, not necessarily the same thing as the
;;   head or tip revision.  Should return "0" for a file added but not yet
;;   committed.

On success `hg parent' command returns 0 and prints the parent of FILE. For
not registered, as added but not commited files, throws error code and
prints a message, so could check the returning value to substitute the
printed message with "0" as vc.el requires. Here it is proposed the
catch/throw mechanism.

2014-05-24 Santiago Payà i Miralta <[email-masked]>

        * lisp/vc/vc-hg.el (vc-hg-working-revision): Fix
        returning working revision instead of last revision.

>From 426ae4ae2f4ed6f26fc65bb5023fe79ba79686ae Mon Sep 17 00:00:00 2001
From: Santiago Payà i Miralta <[email-masked]>
Date: Sat, 24 May 2014 00:20:19 +0200
Subject: [PATCH] * lisp/vc/vc-hg.el (vc-hg-working-revision): Fix returning
 working revision instead of last revision.

Actually this function uses the `hg log -l 1' command that returns the last
commited revision, not the last checked out revision. When checking out a
specified revision with `hg update REV' the actual revision of FILE is
returned by `hg parent'.

vc.el:
;; * working-revision (file)
;;
;;   Return the working revision of FILE.  This is the revision fetched
;;   by the last checkout or update, not necessarily the same thing as the
;;   head or tip revision.  Should return "0" for a file added but not yet
;;   committed.

On success `hg parent' command returns 0 and prints the parent of FILE. For
not registered, as added but not commited files, throws error code and
prints a message, so could check the returning value to substitute the
printed message with "0" as vc.el requires. Here it is proposed the
catch/throw mechanism.
---
 lisp/vc/vc-hg.el |   13 ++++++++-----
 1 file changed, 8 insertions(+), 5 deletions(-)

diff --git a/lisp/vc/vc-hg.el b/lisp/vc/vc-hg.el
index 05b53a3..0326456 100644
--- a/lisp/vc/vc-hg.el
+++ b/lisp/vc/vc-hg.el
@@ -230,11 +230,14 @@ highlighting the Log View buffer."
   (let ((default-directory (if (file-directory-p file)
                                (file-name-as-directory file)
                              (file-name-directory file))))
-    (ignore-errors
-      (with-output-to-string
-        (process-file vc-hg-program nil standard-output nil
-                      "log" "-l" "1" "--template" "{rev}"
-                      (file-relative-name file))))))
+    (catch 'wrap
+      (ignore-errors
+ (with-output-to-string
+  (if (/= 0
+  (process-file vc-hg-program nil standard-output nil
+ "parent" "--template" "{rev}"
+ (file-relative-name file))
+  )(throw 'wrap "0")))))))

 ;;; History functions

-- 
1.7.9.5