git diff-tree output inconsistency?

[Arjen Laarhoven <arjen@yaph.org>]

Hi all,

I was fiddling with the git-diff-tree command to retrieve a list of
files which have in a commit:

$ git diff-tree --name-only HEAD

According to the documentation, the output starts with the SHA-1 of the
tree-ish given, after which the list of changed files follows.  This is
the case when just one commit-id is given.

However, when given 2 tree-ish objects, the separate line with the SHA-1
is not shown.

I browsed through the code and the history for diff-tree.c, but couldn't
find an explanation for the inconsistency.  The documentation for the
--no-commit-id confuses me a bit more, as it states that the commit id
is shown 'when applicable'.  Unfortunately, it fails to explain when
exactly that is :-)

Have I found a documentation bug/shortcoming, is it a code bug or am I
misunderstanding something else?

Arjen

-- 
Arjen Laarhoven

The presence of those seeking the truth is infinitely to be preferred to 
those who think they've found it.
                                -- Terry Pratchett, "Monstrous Regiment"