Re: [PATCH] scripts/setlocalversion: Improve -dirty check with git-status --no-optional-locks

[Alexander Kapshuk]

On Sun, Nov 11, 2018 at 4:48 PM Alexander Kapshuk
<alexander.kapshuk@xxxxxxxxx> wrote:
>
> On Sat, Nov 10, 2018 at 10:12 PM Genki Sky <sky@xxxxxxxx> wrote:
> >
> > Hi Andreas,
> >
> > On Sat, 10 Nov 2018 11:42:11 +0100, Andreas Schwab <schwab@xxxxxxxxxxxxxx> wrote:
> > > On Nov 10 2018, Genki Sky <sky@xxxxxxxx> wrote:
> > > > On Fri, 9 Nov 2018 10:34:37 -0800, Brian Norris <briannorris@xxxxxxxxxxxx> wrote:
> > > >> +          git_status="$(git --no-optional-locks status -uno --porcelain 2>/dev/null)"
> > > >> +          if [ $? -eq 0 ]; then
> > > >> +                  if echo "$git_status" | grep -qv '^.. scripts/package'; then
> > > >
> > > > Shouldn't this be:
> > > >
> > > >     if printf '%s' "$git_status" | grep -qv '^.. scripts/package'; then
> > > >
> > > > I.e., use printf not echo? Because of echo introducing a newline.
> > >
> > > The input to grep should be a text file, thus should end with a newline.
> >
> > Ah okay, thanks. I guess GNU grep was being lenient. Well then, I
> > think the line at least needs to be changed to:
> >
> >         if [ -n "$git_status" ] && echo "$git_status" | grep -qv '^.. scripts/package'; then
> >
> > I'm just trying to say that in the proposed patch, if git doesn't
> > print anything, the echo adds a newline that wasn't there before. This
> > causes the grep -qv to exit with status 0 (because there's at least
> > one line that doesn't contain '^.. scripts/package'). Meaning it will
> > print dirty.
>
> Piping the output of the git command to grep and using the return status
> of grep as the test condition within the if block, would be sufficient
> to determine whether or not '-dirty' should be printed.
>
> Sample run:
> % if git --no-optional-locks \
>         status -uno --porcelain \
>         2>/dev/null |
>         grep -qv '^.. scripts/package'
> then
>         printf '%s' -dirty
> fi
> %

To improve the readability, the git command may be stored in a variable
and substituted into a command within the if block like so:

% cmd='git
--no-optional-locks
status
-uno
--porcelain'

% if $cmd 2>/dev/null | grep -qv '^.. scripts/package'; then
        printf '%s' -dirty
fi
%