[PATCH v2] devtools: check for supported git version

[Chaoyong He]

> On 10/26/2022 7:24 AM, David Marchand wrote:
> > On Tue, Oct 25, 2022 at 12:15 PM Ali Alnubani <alialnu at nvidia.com> wrote:
> >>
> >> The script devtools/parse-flow-support.sh uses the git-grep option
> >> (-o, --only-matching), which is only supported from git version 2.19
> >> and onwards.[1]
> >>
> >> The script now exits early providing a clear message to the user
> >> about the required git version instead of showing the following error
> >> messages multiple times:
> >>    error: unknown switch `o'
> >>    usage: git grep [<options>] [-e] <pattern> [<rev>...] [[--] <path>...]
> >>    [..]
> >>
> >> [1]
> >> https://github.com/git/git/blob/v2.19.0/Documentation/RelNotes/2.19.0
> >> .txt
> >>
> >> Signed-off-by: Ali Alnubani <alialnu at nvidia.com>
> >> Signed-off-by: Thomas Monjalon <thomas at monjalon.net>
> >
> > I don't have a "non working" git, but the patch lgtm.
> >
> > Acked-by: David Marchand <david.marchand at redhat.com>
> >
> 
> +Chaoyong,
> 
> He had observed the problem, perhaps he can help to test.

I test in my host, it does work.

$ git --version
git version 2.18.5

Before this patch:
$ ./devtools/check-doc-vs-code.sh
error: unknown switch `o'
usage: git grep [<options>] [-e] <pattern> [<rev>...] [[--] <path>...]
    --cached              search in index instead of in the work tree
    ...
repeat many times.

After this patch:
$ ./devtools/check-doc-vs-code.sh
git version >= 2.19 is required