From: Michael J Gruber <git@drmicha.warpmail.net>
Date: Mon, 15 Sep 2008 20:49:06 GMT
Subject: Re: Diff-tree does not work for initial commit
Message-ID: <48CECA42.1050209@drmicha.warpmail.net>
In-Reply-To: <3665a1a00809151301p7d8e6387g3cacfb879b45da2f@mail.gmail.com>

Anatol Pomozov venit, vidit, dixit 15.09.2008 22:01:
> Hi, It looks like I found a bug in git.
> 
> The problem: In my script I need to know what files were modified by 
> given commit. I use diff-tree for it. Although it works for most 
> cases, for initial commit it does not. Here is a sequence of actions.
> 
> 
> anatol:~ $ mkdir mkdir initialcommitissue anatol:~ $ cd
> initialcommitissue/ anatol:initialcommitissue $ git init Initialized
> empty Git repository in /home/anatol/initialcommitissue/.git/ 
> anatol:initialcommitissue $ echo "First commit" > 1.txt 
> anatol:initialcommitissue $ git add 1.txt anatol:initialcommitissue $
> git commit -m "First commit" Created initial commit 31ccc6a: First
> commit 1 files changed, 1 insertions(+), 0 deletions(-) create mode
> 100644 1.txt anatol:initialcommitissue $ git diff-tree HEAD     <<<<<
> PROBLEM IS HERE

>From the man page:

       Compares the content and mode of the blobs found via two tree
objects.

       If there is only one <tree-ish> given, the commit is compared
with its parents (see --stdin below).

       Note that git-diff-tree can use the tree encapsulated in a commit
object.


The initial commit has no parent, so diff-tree does not know which tree
to compare to.

You can do

git diff-tree 4b825dc642cb6eb9a060e54bf8d69288fbee4904 HEAD

but I guess you suggest that diff-tree should do that automatically for
a single parentless treeish: bug -> RFE

diff-tree is plumbing. Would this change break anything?

Michael