Re: [PATCH 1/5] libxfs-apply: don't add duplicate headers

["Darrick J. Wong" <darrick.wong@oracle.com>]

On Wed, Nov 25, 2020 at 03:12:39PM -0600, Eric Sandeen wrote:
> On 11/25/20 2:38 PM, Darrick J. Wong wrote:
> > From: Darrick J. Wong <darrick.wong@oracle.com>
> > 
> > When we're backporting patches from libxfs, don't add a S-o-b header if
> > there's already one at the end of the headers of the patch being ported.
> > 
> > That way, we avoid things like:
> > Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
> > Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
> 
> But it will still not add my additional SOB if I merge something across to
> userspace that starts out with:
> 
> Signed-off-by: Eric Sandeen <sandeen@redhat.com>
> Reviewed-by: Dave Chinner <dchinner@redhat.com>
> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
> 
> And I always felt like the committer should be adding their SOB to the end of
> the chain when they move code from one place to another, especially if any
> tweaks got made along the way.
> 
> IOWs I see the rationale for removing duplicate /sequential/ SOBs, but not
> for removing duplicate SOBs in general.
> 
> Am I thinking about that wrong?

add_header is different from last time -- whereas before it would search
the entire $hdrfile for $hdr and add $hdr if it didn't find a match, now
it only looks at the last line of $hdrfile for a match.

For your example above, it would not add another "SOB: Darrick" because
there's already one at the bottom of the headers; but it would add
another "SOB: Eric" because this commit acquired other tags after your
first signoff.

--D

> > ---
> >  tools/libxfs-apply |   14 +++++++++++---
> >  1 file changed, 11 insertions(+), 3 deletions(-)
> > 
> > 
> > diff --git a/tools/libxfs-apply b/tools/libxfs-apply
> > index 3258272d6189..9271db380198 100755
> > --- a/tools/libxfs-apply
> > +++ b/tools/libxfs-apply
> > @@ -193,6 +193,14 @@ filter_xfsprogs_patch()
> >  	rm -f $_libxfs_files
> >  }
> >  
> > +add_header()
> > +{
> > +	local hdr="$1"
> > +	local hdrfile="$2"
> > +
> > +	tail -n 1 "$hdrfile" | grep -q "^${hdr}$" || echo "$hdr" >> "$hdrfile"
> > +}
> > +
> >  fixup_header_format()
> >  {
> >  	local _source=$1
> > @@ -280,13 +288,13 @@ fixup_header_format()
> >  	sed -i '${/^[[:space:]]*$/d;}' $_hdr.new
> >  
> >  	# Add Signed-off-by: header if specified
> > -	if [ ! -z ${SIGNED_OFF_BY+x} ]; then 
> > -		echo "Signed-off-by: $SIGNED_OFF_BY" >> $_hdr.new
> > +	if [ ! -z ${SIGNED_OFF_BY+x} ]; then
> > +		add_header "Signed-off-by: $SIGNED_OFF_BY" $_hdr.new
> >  	else	# get it from git config if present
> >  		SOB_NAME=`git config --get user.name`
> >  		SOB_EMAIL=`git config --get user.email`
> >  		if [ ! -z ${SOB_NAME+x} ]; then
> > -			echo "Signed-off-by: $SOB_NAME <$SOB_EMAIL>" >> $_hdr.new
> > +			add_header "Signed-off-by: $SOB_NAME <$SOB_EMAIL>" $_hdr.new
> >  		fi
> >  	fi
> >  
> >