Add a Packages-Require-Authorization Release file field

This new field allows a repository to declare that access to
packages requires authorization. The current implementation will
set the pin to -32768 if no authorization has been provided in
the auth.conf(.d) files.

This implementation is suboptimal in two aspects:
(1) A repository should behave more like NotSource repositories
(2) We only have the host name for the repository, we cannot use
    paths yet.

- We can fix those after an ABI break.

The code also adds a check to acquire-item.cc to not use the
specified repository as a download source, mimicking NotSource.

(cherry picked from commit c2b9b0489538fed4770515bd8853a960b13a2618)
LP: #1814727
(cherry picked from commit d75162bc67d5a1a690eb2a8747d31ad68353823e)
(cherry picked from commit 19075f52174199fe7665334ad1815c747c26c10b)

Conflicts:
	apt-pkg/deb/debmetaindex.cc
	apt-pkg/pkgcache.h

1 files changed, 1 insertions, 0 deletions

diff --git a/apt-pkg/deb/deblistparser.cc b/apt-pkg/deb/deblistparser.cc
index 02b9cb239..7c18286fc 100644
--- a/apt-pkg/deb/deblistparser.cc
+++ b/apt-pkg/deb/deblistparser.cc
@@ -926,6 +926,7 @@ bool debListParser::LoadReleaseInfo(pkgCache::PkgFileIterator &FileI,
    #undef APT_INRELEASE
    Section.FindFlag("NotAutomatic", FileI->Flags, pkgCache::Flag::NotAutomatic);
    Section.FindFlag("ButAutomaticUpgrades", FileI->Flags, pkgCache::Flag::ButAutomaticUpgrades);
+   Section.FindFlag("Packages-Require-Authorization", FileI->Flags, pkgCache::Flag::PackagesRequireAuthorization);
 
    return !_error->PendingError();
 }