Re: [feature request] Make "commit --only" work with new files

[Johannes Schindelin <Johannes.Schindelin@gmx.de>]

Hi Luis,

On Fri, 25 Nov 2016, Luis Ressel wrote:

> currently "git commit --only <file>" only works if <file> is already
> checked into the repo, but not with newly created and still untracked
> files (builtin/commit.c:list_path() throws the error "error: pathspec
> '<file>' did not match any file(s) known to git.")
> 
> I don't think this limitation is intented. I've had a look at the
> relevant part of builtin/commit.c, but unfortunately it wasn't obvious
> to me how to fix this.

The best way to go about it is probably to define the desired behavior
first, in the form of a patch to the test suite. Personally, I would
extend t/t7509-commit.sh with a new test case.

Then, once you have that test case (that should be marked with
test_expect_failure, because it fails for now), you can use a debugger
such as gdb to single-step into the relevant function (I guess
"prepare_index()" is a good candidate) to find out why the files are not
added.

From there, it should be easier to figure out what to patch, and how.

Good hunting!
Johannes