[DOC BUG] git tag uses GIT_COMMITTER_DATE, not GIT_AUTHOR_DATE

From: Kalle Olavi Niemitalo <kon@iki.fi>
Date: Feb 11, 2008, 08:38 UTC
Message-ID: <87ir0vc2gw.fsf@Astalo.kon.iki.fi>

In Git v1.5.4.1, Documentation/git-tag.txt advises:

> To set the date used in future tag objects, set the environment
> variable GIT_AUTHOR_DATE to one or more of the date and time.  The
> date and time can be specified in a number of ways; the most common
> is "YYYY-MM-DD HH:MM".

But this does not work because git tag uses GIT_COMMITTER_DATE instead. In builtin-tag.c:

Show 9 quoted lines

> 	header_len = snprintf(header_buf, sizeof(header_buf),
> 			  "object %s\n"
> 			  "type %s\n"
> 			  "tag %s\n"
> 			  "tagger %s\n\n",
> 			  sha1_to_hex(object),
> 			  typename(type),
> 			  tag,
> 			  git_committer_info(IDENT_ERROR_ON_NO_NAME));

i.e. it does not call git_author_info.

The backdating section was added to git-tag.txt in 5040beff, and builtin-tag.c already used git_committer_info at that time. The older git-tag.sh used tagger=$(git-var GIT_COMMITTER_IDENT). Thus it seems the bug is in the documentation, not in the code.