Re: Bug?: git archive exclude pathspec and gitattributes export-ignore

From: René Scharfe <l.s.r@web.de>
Date: Aug 14, 2017, 16:43 UTC
Message-ID: <ae893c19-652d-1c8f-50ba-1242b95be84e@web.de>
In-Reply-To: <alpine.DEB.2.11.1708131240360.15538@motsugo.ucc.gu.uwa.edu.au>

Am 13.08.2017 um 06:53 schrieb David Adam:

Show 37 quoted lines

> Hi all,
> 
> I think I have a bug in git (tested 2.11.0 on Debian 8, 2.14.1 on OS X and
> 2.14.1.145.gb3622a4 on OS X).
> 
> Given a repository with an export-ignore directive for a subdirectory in
> .gitattributes, `git archive` with a pathspec that excludes a different
> subdirectory produces no output file and git exits with -1 as the return
> status.
> 
> As shown:
> 
>     > git init foo && cd foo
>     Initialized empty Git repository in /Users/david/src/foo/.git/
>     > mkdir a b
>     > touch {a,b}/somefile
>     > echo "/a export-ignore" >> .gitattributes
>     > git add .
>     > git commit -m "Initial commit"
>     [master (root-commit) 53527a7] Initial commit
>      3 files changed, 1 insertion(+)
>      create mode 100644 .gitattributes
>      create mode 100644 a/somefile
>      create mode 100644 b/somefile
>     > git archive --verbose master ':(top)' ':(exclude)b*'
>     .gitattributes
>     > echo $?
>     255
> 
> If this is intended behaviour, is there any way of achieving the goal of
> excluding a subdirectory not listed as export-ignore? Using the exclude
> pathspec ":(exclude)b" produces an empty subdirectory b in the output,
> which I would like to avoid.
> 
> This is a reduced testcase; my goal is to end up with two archives, one
> containing directory b only, and one containing everything except for
> directory b - so I can't just add 'b export-ignore' to gitattributes.

Thanks for the thoughtful bug report!

The problem seems to be that archive.c::write_archive_entry() returns 0 instead of READ_TREE_RECURSIVE for directories with the attribute "export-ignore", and archive.c::write_directory() gets caught by surprise by that and returns -1, which ends up causing git archive to exit with return code 255 without actually writing anything.

This should only happen if you use wildcards like "*", i.e. git archive should behave as expected if you spell out the full name of the directory. Can you confirm that?

The real solution is probably to teach tree-walk.c::do_match() how to handle attributes and then inject ":(attr:-export-ignore)" as a default internal pathspec in archive.c::parse_pathspec_arg() instead of handling it in archive.c::write_archive_entry().

@Duy: What do you think?

Thanks, René