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Message-ID: <9f9a0740aef282d30af8fa02ca7c6479e80aa9a0.camel@perches.com>
Subject: Re: [PATCH v4] checkpatch: warn for non-standard fixes tag style
From:   Joe Perches <joe@perches.com>
To:     "niklas.soderlund@corigine.com" <niklas.soderlund@corigine.com>,
        Philippe Schenker <philippe.schenker@toradex.com>
Cc:     "corbet@lwn.net" <corbet@lwn.net>,
        "dwaipayanray1@gmail.com" <dwaipayanray1@gmail.com>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        "linux-doc@vger.kernel.org" <linux-doc@vger.kernel.org>,
        "lukas.bulwahn@gmail.com" <lukas.bulwahn@gmail.com>,
        "apw@canonical.com" <apw@canonical.com>,
        "sfr@canb.auug.org.au" <sfr@canb.auug.org.au>,
        "louis.peens@corigine.com" <louis.peens@corigine.com>,
        "simon.horman@corigine.com" <simon.horman@corigine.com>,
        "oss-drivers@corigine.com" <oss-drivers@corigine.com>
In-Reply-To: <Yxrt1aa60xY0H7j0@oden.dyn.berto.se>
References: <20220908164434.122106-1-niklas.soderlund@corigine.com>
         <3275d886491dc934e3277cde9cc766b0ce0886ea.camel@toradex.com>
         <Yxrt1aa60xY0H7j0@oden.dyn.berto.se>
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Date:   Fri, 09 Sep 2022 10:57:10 -0700
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On Fri, 2022-09-09 at 09:40 +0200, niklas.soderlund@corigine.com wrote:
> On 2022-09-08 17:49:14 +0000, Philippe Schenker wrote:
> > Thanks for adding me to cc. I will also add Stephen, as he also sent
> > some comments on my submission the exact same problem. I'm supportive of
> > your code as it has the nice advantage of suggesting the right format of
> > the tag if it might be wrong. However it seems lot of stuff is slightly
> > duplicated and lots of lines could be left away simplifying it greatly.

It's not very possible to reduce the line count here.
I mentioned the same thing in my first reply.

> > > +# Check Fixes: styles is correct
> > > +???????????????if (!$in_header_lines && $line =~ /^fixes:?/i) {
> > 
> > I would check all lines that start with fixes, even if there is
> > whitespace in front (and then failing later on...)
> > 
> > if (!$in_header_lines && $line =~ /^\s*fixes:?/i) {

I think that's a poor idea.

You should really review git history for lines that start with fixes
and look at the number of false positives that would give.

Try this grep:

$ git log -100000 --no-merges --grep="^\s*fixes" -i --format=email -P | \
  grep -P -i "^\s*fixes)" | \
  grep -P -v "^Fixes: [0-9a-f]{12,}'
[...]

That is a greater than 10% false positive rate.

I think it's better to make sure that there is a likely SHA1 of some
minimum length after the fixes line.

And a relatively common defect is to have the word "commit" after fixes.

e.g.:

Fixes commit 554c0a3abf216 ("staging: Add rtl8723bs sdio wifi driver").
Fixes commit a2c60d42d97c ("Add files for new driver - part 16").

So maybe:

	if (!$in_header_lines &&
	    $line =~ /^\s*fixes:?\s*(?:commit\s*)?[0-9a-f]{5,}\b/i)