Re: [Quilt-dev] diff output header/format question

[Jean Delvare]

Hi Randy,

On Fri, 7 Oct 2022 15:01:36 -0700, Randy Dunlap wrote:
> Search on lore.kernel.org (at least when searching by patchid, commitid)
> looks for a "^diff" line before the ---/+++ lines in a patch.
> 
> Can anyone suggest a way to cause or create that line?

As far as I know, quilt can't currently do this. What it can do is
print an Index header which looks like this:

Index: b/arch/ia64/mm/numa.c
===================================================================

If lore.kernel.org is happy with that, then all you need to do is
ensure that you did not set QUILT_NO_DIFF_INDEX in ~/.quilrc or
/etc/quilt.quiltrc.

> So instead of
> 
> --- a/arch/ia64/mm/numa.c
> +++ b/arch/ia64/mm/numa.c
> 
> at the beginning of a file's patch, it would be 3 lines:
> (a la git but without the "--git")
> 
> 
> diff a/arch/ia64/mm/numa.c b/arch/ia64/mm/numa.c
> --- a/arch/ia64/mm/numa.c
> +++ b/arch/ia64/mm/numa.c

If there any tool other than git which inserts such lines before the
actual unified diff? GNU diff does not, unless I missed an option.

> AFAICT quilt has no problem reading patches like this, since
> whenever I get a (git) patch from other people to test, I apply
> it with quilt and then rebuild the kernel.

Correct, quilt will ignore the line and be happy with it (just like GNU
patch).

It shouldn't be too hard to add an option to quilt to optionally
generate that line. However users will be free to use that option or
not, so it doesn't really solve the problem at large (we can search for
your patches, but not random quilt user patches). Shouldn't
lore.kernel.org be improved to recognize patches without that line
instead?

-- 
Jean Delvare
SUSE L3 Support