bug#15696: 24.3; vc-git-annotate-command -- ambiguous short commit hashes cause failures

bug#15696: 24.3; vc-git-annotate-command -- ambiguous short commit hashes cause failures

[Phil Sainty]

`vc-git-annotate-command' looks like this:

(defun vc-git-annotate-command (file buf &optional rev)
  (let ((name (file-relative-name file)))
    (vc-git-command buf 'async nil "blame" "--date=iso" "-C" "-C" rev "--"
name)))

By default, git blame produces short commit hashes. You need to pass
the -l argument to make it produce full hashes.

This is a problem if the short hash is ambiguous, as none of the
vc-annotate commands for interacting with that commit work.

Example errors for ambiguous commit hash 7b10edf8:

'f' (`vc-annotate-find-revision-at-line'):
Checking out (filename).~7b10edf8~...
vc-do-command: Running git cat-file blob 7b... ....FAILED (status 128)

'D' (`vc-annotate-show-changeset-diff-revision-at-line'):
Cannot diff from any revision prior to 7b10edf8

'l' (`vc-annotate-show-log-revision-at-line'):
error: short SHA1 7b10edf8 is ambiguous.
fatal: bad revision '7b10edf8'

'a' (`vc-annotate-revision-previous-to-line'):
vc-annotate-warp-revision: Invalid argument to vc-annotate-warp-revision

On the command line:
$ git show 7b10edf8
error: short SHA1 7b10edf8 is ambiguous.
error: short SHA1 7b10edf8 is ambiguous.
fatal: ambiguous argument '7b10edf8': unknown revision or path not in the
working tree.
Use '--' to separate paths from revisions


I suspect the best solution is to pass -l by default, and perhaps
*hide* the remainder of the full commit hash in the annotate buffer
-- but internally always utilise the full hash for all commands.

(Will this also be a problem elsewhere in the vc-git support?)


-Phil




In GNU Emacs 24.3.1 (x86_64-unknown-linux-gnu, GTK+ Version 3.4.2)
 of 2013-03-12 on shodan
Windowing system distributor `The X.Org Foundation', version 11.0.11103000
System Description:	Ubuntu 12.04.3 LTS

Configured using:
 `configure '--prefix=/home/phil/emacs/emacs24/emacs-24.3/usr/local''

Important settings:
  value of $LANG: en_NZ.UTF-8
  locale-coding-system: utf-8-unix
  default enable-multibyte-characters: t

Major mode: Lisp Interaction

Minor modes in effect:
  tooltip-mode: t
  mouse-wheel-mode: t
  tool-bar-mode: t
  menu-bar-mode: t
  file-name-shadow-mode: t
  global-font-lock-mode: t
  font-lock-mode: t
  blink-cursor-mode: t
  auto-composition-mode: t
  auto-encryption-mode: t
  auto-compression-mode: t
  line-number-mode: t
  transient-mark-mode: t

Recent input:
<help-echo> M-x r e p o r t - e m <tab> <return>

Recent messages:
For information about GNU Emacs and the GNU system, type C-h C-a.

Load-path shadows:
None found.

Features:
(shadow sort gnus-util mail-extr emacsbug message format-spec rfc822 mml
easymenu mml-sec mm-decode mm-bodies mm-encode mail-parse rfc2231
mailabbrev gmm-utils mailheader sendmail rfc2047 rfc2045 ietf-drums
mm-util mail-prsvr mail-utils time-date tooltip ediff-hook vc-hooks
lisp-float-type mwheel x-win x-dnd tool-bar dnd fontset image regexp-opt
fringe tabulated-list newcomment lisp-mode register page menu-bar
rfn-eshadow timer select scroll-bar mouse jit-lock font-lock syntax
facemenu font-core frame cham georgian utf-8-lang misc-lang vietnamese
tibetan thai tai-viet lao korean japanese hebrew greek romanian slovak
czech european ethiopic indian cyrillic chinese case-table epa-hook
jka-cmpr-hook help simple abbrev minibuffer loaddefs button faces
cus-face macroexp files text-properties overlay sha1 md5 base64 format
env code-pages mule custom widget hashtable-print-readable backquote
make-network-process dbusbind dynamic-setting system-font-setting
font-render-setting move-toolbar gtk x-toolkit x multi-tty emacs)

bug#15696: 24.3; vc-git-annotate-command -- ambiguous short commit hashes cause failures

[Lars Ingebrigtsen]

"Phil Sainty" <psainty@orcon.net.nz> writes:

> `vc-git-annotate-command' looks like this:
>
> (defun vc-git-annotate-command (file buf &optional rev)
>   (let ((name (file-relative-name file)))
>     (vc-git-command buf 'async nil "blame" "--date=iso" "-C" "-C" rev "--"
> name)))
>
> By default, git blame produces short commit hashes. You need to pass
> the -l argument to make it produce full hashes.
>
> This is a problem if the short hash is ambiguous, as none of the
> vc-annotate commands for interacting with that commit work.
>
> Example errors for ambiguous commit hash 7b10edf8:

(This bug report unfortunately got no response at the time.)

The command in question now produces an 11-char short hash, which I
think is pretty rarely ambiguous, in my experience, so I don't think
there's anything more to fix here, and I'm closing this bug report.

If there's still a problem here, please respond to the debbugs address
and we'll reopen.

-- 
(domestic pets only, the antidote for overdose, milk.)
   bloggy blog: http://lars.ingebrigtsen.no