Re: git diff bug?

From: Jeff King <peff@peff.net>
Date: Apr 4, 2009, 01:45 UTC
Message-ID: <20090404014527.GA13350@coredump.intra.peff.net>
In-Reply-To: <m2ocvdkyul.fsf@boostpro.com>

On Fri, Apr 03, 2009 at 09:10:42PM -0400, David Abrahams wrote:

Show 6 quoted lines

> 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".

-Peff