Re: [Outreachy] Introduction

[Phillip Wood <phillip.wood123@gmail.com>]

Hi Sangeeta

On 11/10/2020 12:30, Sangeeta NB wrote:
> Thanks for the help, Philip.
> 
> On Fri, Oct 9, 2020 at 11:59 PM Phillip Wood <phillip.wood123@gmail.com> wrote:
> 
>> I struggled to find the mircoprojects page - I must have missed the link
>> on the outreachy site.
> 
> In case anyone else is struggling to find the microprojects page,
> here's the link [1]
> 
> [1] https://git.github.io/Outreachy-21-Microprojects/
> 
>> As I understand it if a submodule contains any untracked files (i.e. a
>> file that has not been added with `git add` and is not ignored by any
>> .gitignore or .git/info/exclude entries) then running `git diff` in the
>> superproject will report that the submodule is dirty - there will be a
>> line something like "+Subproject commit abcdef-dirty". However if we run
>> `git describe --dirty` in the submodule directory then it will not
>> append "-dirty" to it's output unless there are changes to tracked files.
> 
> On running `git diff HEAD --ignore-submodules=untracked` the submodule
> wasn't reported as dirty.

That's great

> I guess this is what we are expecting. So should I make it the default
> behavior for diff?

I think that is a good route forward, we probably want to change the 
default for `diff-index` and `diff-files` as well

> 
> A fix for making this as the default behaviour can be:
> 
> --- a/diff.c
> +++ b/diff.c
> @@ -422,6 +422,7 @@ int git_diff_ui_config(const char *var, const char
> *value, void *cb)
>          if (git_color_config(var, value, cb) < 0)
>                  return -1;
> 
> +       handle_ignore_submodules_arg(&default_diff_options, "untracked");
>          return git_diff_basic_config(var, value, cb);
>   }
> 
> But this would also involve a lot of changes in the way tests are
> written as 12 out of 19 tests in t4027-diff-submodule.sh failed after
> adding this patch. I am working on any other workaround for this. Let
> me know whether I am on right path or not. Also any pointers on how to
> proceed would be helpful. Thanks!

We'd expect some tests to fail but only the ones that are testing if 
untracked files cause the submodule to be considered dirty.

git_diff_ui_config() is a callback that is invoked once per config key 
in the config files so I don't think it is a good place to make the 
change as it is inefficient and overrides the users' 
`diff.ignoreSubmodules` setting . It also only applies to `diff` and not 
`diff-index` or `diff-files`. I think it would be better to set the 
default in diff_setup() though we need to be careful not to override 
`diff.ignoreSubmodules` setting so we might need to add a global flag to 
remember if the user has set `diff.ignoreSubmodules` in their config

Best Wishes

Phillip

>