Bug#1051824: linux-patch-VER-rt.patch.xz went missing

[Helmut Grohne <helmut@subdivi.de>]

Package: linux-source-6.1
Version: 6.1~rc3-1~exp1
X-Debbugs-Cc: waldi@debian.org

Hi,

I noticed that linux-patch-VER-rt.patch.xz is missing from
linux-source-VER lately. I tracked this down to having gone missing
exactly when we moved from 6.0 to 6.1, i.e. all 6.0 builds include it
and all 6.1 builds lack it. Digging deeper, I couldn't identify a
regressing git commit, but Bastian's work on restructuring makefile
targets stands out. If looking at build logs, you can see that in
current builds ALL_FEATURESETS is no longer set and this is why the
relevant dependency is skipped.

gencontrol.py def do_main_makefile is probably relevant here. It ends
with:

        makeflags = makeflags.copy()
        makeflags['ALL_FEATURESETS'] = ' '.join(iter_featuresets(self.config))
        super().do_main_makefile(makeflags, extra)

In former kernels, the super method was non-empty and consumed the
updated makeflags, but this is no longer the case, the super method now
simply says "pass", so this code block has effectively become a no-op.

On the flip side, I tried to see what would happen if we'd update the
global makeflags with ALL_FEATURESETS (e.g. by deleting the dict copy).
And indeed, once doing that the rt patch is included in the -source
package again. This probably is not the right solution, but I hope this
bit helps pin down the cause.

In any case, it seems evident that the deletion of
linux-patch-VER-rt.patch.xz is accidental rather than intentional. Would
you be able to restore its presence?

Helmut