Re: Getting a commit sha1 from fast-import in a remote-helper

[Mike Hommey <mh@glandium.org>]

On Mon, Nov 17, 2014 at 05:40:28PM -0800, Jonathan Nieder wrote:
> Mike Hommey wrote:
> 
> > - fast-import's `ls` command documentation about its output format
> >   mentions that the output may contain commits, so I tried the trick of
> >   creating a tree with commits, but fast-import then fails with:
> >     fatal: Not a blob (actually a commit)
> >   which I totally understand, but then I wonder why the documentation
> >   mentions it and how one would get a tree containing references to
> >   commits. I guess the documentation should be fixed.
> 
> Odd.  Here's what happens when I try:
> 
>  $ echo "ls $(git rev-parse HEAD)" | git fast-import --quiet
>  fatal: Missing space after tree-ish: ls a4a226a366ab0a173ed9e5f70f2a95d0d21e54c5
>  fast-import: dumping crash report to .git/fast_import_crash_14080
>  $ echo "ls $(git rev-parse HEAD) " | git fast-import --quiet
>  040000 tree d3d38e7d71cb40ebbaf2798b01837b3de43fd4a1
> 
> How did you get that "Not a blob" message?

When trying to *create* a tree with a commit in it, so instead of giving
the mark for a blob to a filemodify command, giving a mark for a commit.
That is what fails with "Not a blob".
So it's not possible to create a tree with a reference to a commit, at
least with fast-import.
But, the documentation for the ls command says this:

   Output uses the same format as git ls-tree <tree> -- <path>:

        <mode> SP ('blob' | 'tree' | 'commit') SP <dataref> HT <path> LF

The 'commit' string certainly seems it cannot be there.

> I think a good fix would be to teach parse_ls a mode with no <path>
> parameter.  Something like this (untested; needs cleanup and tests):

This would make both your commands output the same thing, right? It
wouldn't help my case :)

Mike