Re: [Quilt-dev] [PATCH RFC] Add option --preamble to diff and refresh

[Andreas Grünbacher]

Jean and Randy,

Am Do., 13. Okt. 2022 um 14:43 Uhr schrieb Jean Delvare <jdelvare@suse.de>:
> Option --preamble can be used to let quilt generate extra lines
> before the actual diff. For now one preamble format is supported,
> "diff", which will generate a line like:
>
> > diff -- a/dir/file b/dir/file
>
> This is meant to help other tools recognize the beginning of the
> patch body, namely lore.kernel.org.

before adding such an awful hack to quilt, could you please pass this
by Junio, git@vger.kernel.org, and Konstantin to see if this can be
fixed in "git patch-id" instead? After all, this affects all quilt
patches ever posted so far, countless others that will still be
posted, and possibly patches generated by other tools as well.

> Suggested-by: Randy Dunlap <rdunlap@infradead.org>
> Signed-off-by: Jean Delvare <jdelvare@suse.de>
> ---
> Randy, this is a tentative implementation of the feature you requested.
> Please give it a try and let me know if it works for you.
>
> Note that I made the line start with "diff --" rather than just "diff".
> The reason is that just matching for "^diff " could easily lead to
> false positives as this pattern could legitimately appear in the patch
> header. This is compatible with the way quilt currently detects the
> start of body for git-generated patches.

Not sure the extra "--" is actually helping.

> I am moderately happy with the implementation, somehow it feels like
> --no-index and --preamble should be merged into a single option, but it
> seems difficult to do that without breaking backward compatibility. But
> I don't know if we care.
>
>  doc/quilt.1.in            |    8 ++++++++
>  quilt/diff.in             |    8 +++++++-
>  quilt/refresh.in          |    8 +++++++-
>  quilt/scripts/patchfns.in |   14 ++++++++++----
>  4 files changed, 32 insertions(+), 6 deletions(-)
>
> --- quilt.orig/quilt/scripts/patchfns.in
> +++ quilt/quilt/scripts/patchfns.in
> @@ -745,10 +745,16 @@ diff_file()
>                 if [[ "$line" =~ ^Binary\ files\ .*\ differ$ ]]
>                 then
>                         status=1
> -               elif [ -z "$QUILT_NO_DIFF_INDEX" ]
> -               then
> -                       echo "Index: $index"
> -                       echo 
> "==================================================================="
> +               else
> +                       if [ -z "$QUILT_NO_DIFF_INDEX" ]
> +                       then
> +                               echo "Index: $index"
> +                               echo 
> "==================================================================="
> +                       fi
> +                       if [ "$QUILT_DIFF_PREAMBLE" == "diff" ]
> +                       then
> +                               echo "diff -- $old_hdr $new_hdr"
> +                       fi
>                 fi
>
>                 echo "$line"
> --- quilt.orig/doc/quilt.1.in
> +++ quilt/doc/quilt.1.in
> @@ -406,6 +406,14 @@ This is shorthand for adding \\[lq]\\-\\
>  and
>  .IR QUILT_REFRESH_ARGS .
>  .TP 4
> +.I QUILT_DIFF_PREAMBLE
> +If set to \\[lq]diff\\[rq], a \\[lq]diff\\[rq] line is prepended to
> +patches generated by .IR quilt .
> +This is shorthand for adding \\[lq]\\-\\-preamble=diff\\[rq] to both
> +.I QUILT_DIFF_ARGS
> +and
> +.IR QUILT_REFRESH_ARGS .
> +.TP 4
>  .I QUILT_NO_DIFF_TIMESTAMPS
>  Boolean flag; if set to anything,
>  no timestamps are included in headers when generating patches.
> --- quilt.orig/quilt/diff.in
> +++ quilt/quilt/diff.in
> @@ -34,6 +34,9 @@ included.
>  --no-index
>         Do not output Index: lines.
>
> +--preamble=diff
> +       Output diff lines.
> +
>  -z     Write to standard output the changes that have been made
>         relative to the topmost or specified patch.
>
> @@ -125,7 +128,7 @@ die()
>
>  options=`getopt -o p:P:RuU:cC:zh --long diff:,snapshot,no-timestamps \
>                                  --long no-index,combine:,color:: \
> -                                --long sort -- "$@"`
> +                                --long sort,preamble: -- "$@"`
>
>  if [ $? -ne 0 ]
>  then
> @@ -175,6 +178,9 @@ do
>         --no-index)
>                 QUILT_NO_DIFF_INDEX=1
>                 shift ;;
> +       --preamble)
> +               QUILT_DIFF_PREAMBLE=$2
> +               shift 2 ;;
>         --sort)
>                 opt_sort=1
>                 shift ;;
> --- quilt.orig/quilt/refresh.in
> +++ quilt/quilt/refresh.in
> @@ -47,6 +47,9 @@ patch.
>  --no-index
>         Do not output Index: lines.
>
> +--preamble=diff
> +       Output diff lines.
> +
>  --diffstat
>         Add a diffstat section to the patch header, or replace the
>         existing diffstat section.
> @@ -77,7 +80,7 @@ die()
>  }
>
>  options=`getopt -o p:uU:cC:fz::h --long no-timestamps,diffstat,backup,sort \
> -                                --long no-index \
> +                                --long no-index,preamble: \
>                                  --long strip-trailing-whitespace -- "$@"`
>
>  if [ $? -ne 0 ]
> @@ -115,6 +118,9 @@ do
>         --no-index)
>                 QUILT_NO_DIFF_INDEX=1
>                 shift ;;
> +       --preamble)
> +               QUILT_DIFF_PREAMBLE=$2
> +               shift 2 ;;
>         --diffstat)
>                 opt_diffstat=1
>                 shift ;;
>
>
> --
> Jean Delvare
> SUSE L3 Support
>
> _______________________________________________
> Quilt-dev mailing list
> Quilt-dev@nongnu.org
> https://lists.nongnu.org/mailman/listinfo/quilt-dev

Thanks,
Andreas