From: David Abrahams <dave@boostpro.com>
Date: Mon, 06 Apr 2009 09:09:32 GMT
Subject: Re: git diff bug?
Message-ID: <1BF9172A-BE91-4D1C-932A-EB9FD79BA402@boostpro.com>
In-Reply-To: <20090404014527.GA13350@coredump.intra.peff.net>


On Apr 3, 2009, at 9:45 PM, Jeff King wrote:

> On Fri, Apr 03, 2009 at 09:10:42PM -0400, David Abrahams wrote:
>
>> Please see
>> http://github.com/techarcana/elisp/commit/63d672c296316c85690085930b05c642b88a9978#diff-2
>>
>> Note how the @@ ... @@ clauses are followed by text from the previous
>> line's comment.  Not sure, but this strikes me as a line-ending  
>> issue.
>> custom.el was originally built on a linux machine; now I'm using a  
>> Mac.
>
> This is as designed. The original file ("git show e7dd7db") contains  
> (my
> numbering seems different than what git produces; it is produced by  
> "nl"
> which is maybe treating some line endings differently earlier in the
> file):
>
>   102   '(mm-attachment-override-types (quote ("text/x-vcard"  
> "application/pkcs7-mime" "application/x-pkcs7-mime" "application/ 
> pkcs7-signature" "application/x-pkcs7-signature" "image/*")) nil nil "
>   103  Added image/* to display attached images inline")
>   104   '(mm-discouraged-alternatives (quote ("text/html" "text/ 
> richtext" "image/.*")) nil nil "
>   105  The documentation for this variable says it all")
>   106   '(mm-inline-text-html-with-images t)
>   107   '(muse-project-alist (quote (("WikiPlanner" ("~/ 
> plans" :default "index" :major-mode planner-mode :visit-link planner- 
> visit-link)))))
>   108   '(org-agenda-files (quote ("~/organizer.org")))
>
> The changed text in your diff starts on 108. So we show 105-107 as
> context lines. The text after the @@ clause is the "function header";
> this is equivalent to "-p" in GNU diff. It's basically a guess about  
> the
> most interesting context to show, and looks alphabetic characters that
> are left-aligned. In the case of lisp, it really isn't all that
> interesting (and what looks so weird is that your file contains
> a lot of
>
>  "\nSome text"
>
> so the text strings are all left-aligned. You can customize the regex
> used to guess at the function header. See "defining a custom
> hunk-header" in "git help attributes".

Hmm, so I tried sticking this .gitattributes in my repo

   *.el   diff=el
   [diff "el"]
         xfuncname = "^(\\(def[a-z]+ .+)$"

and git diff barfed with

   "el"] is not a valid attribute name: .gitattributes:2
   "^(\\(def[a-z]+ is not a valid attribute name: .gitattributes:3

What am I missing?  I tried googling, but from what turns up for me,  
it doesn't look like anyone else has ever tried to use this feature!

TIA,

--
David Abrahams
BoostPro Computing
http://boostpro.com