Add basic support for the Protected field

This will be mapped to Important for the time being.

6 files changed, 26 insertions, 2 deletions

diff --git a/apt-pkg/deb/deblistparser.cc b/apt-pkg/deb/deblistparser.cc
index a86f49dc0..240946529 100644
--- a/apt-pkg/deb/deblistparser.cc
+++ b/apt-pkg/deb/deblistparser.cc
@@ -318,6 +318,8 @@ bool debListParser::UsePackage(pkgCache::PkgIterator &Pkg,
 	 return false;
    if (Section.FindFlag(pkgTagSection::Key::Important,Pkg->Flags,pkgCache::Flag::Important) == false)
       return false;
+   if (Section.FindFlag(pkgTagSection::Key::Protected, Pkg->Flags, pkgCache::Flag::Important) == false)
+      return false;
 
    if (std::find(forceEssential.begin(), forceEssential.end(), Pkg.Name()) != forceEssential.end())
    {
diff --git a/apt-pkg/deb/debsystem.cc b/apt-pkg/deb/debsystem.cc
index 7d4bf7213..eac43c3b7 100644
--- a/apt-pkg/deb/debsystem.cc
+++ b/apt-pkg/deb/debsystem.cc
@@ -466,8 +466,13 @@ pid_t debSystem::ExecDpkg(std::vector<std::string> const &sArgs, int * const inp
 									/*}}}*/
 bool debSystem::MultiArchSupported() const					/*{{{*/
 {
+   return AssertFeature("multi-arch");
+}
+									/*}}}*/
+bool debSystem::AssertFeature(std::string const &feature) /*{{{*/
+{
    std::vector<std::string> Args = GetDpkgBaseCommand();
-   Args.push_back("--assert-multi-arch");
+   Args.push_back("--assert-" + feature);
    pid_t const dpkgAssertMultiArch = ExecDpkg(Args, nullptr, nullptr, true);
    if (dpkgAssertMultiArch > 0)
    {
diff --git a/apt-pkg/deb/debsystem.h b/apt-pkg/deb/debsystem.h
index 2e5a8550c..b3d241512 100644
--- a/apt-pkg/deb/debsystem.h
+++ b/apt-pkg/deb/debsystem.h
@@ -45,6 +45,7 @@ class debSystem : public pkgSystem
    APT_HIDDEN static void DpkgChrootDirectory();
    APT_HIDDEN static pid_t ExecDpkg(std::vector<std::string> const &sArgs, int * const inputFd, int * const outputFd, bool const DiscardOutput);
    bool MultiArchSupported() const override;
+   static bool AssertFeature(std::string const &Feature);
    std::vector<std::string> ArchitecturesSupported() const override;
 
    bool LockInner(OpProgress *const Progress, int timeoutSec) override;
diff --git a/apt-pkg/deb/dpkgpm.cc b/apt-pkg/deb/dpkgpm.cc
index ef73881c8..c496538cc 100644
--- a/apt-pkg/deb/dpkgpm.cc
+++ b/apt-pkg/deb/dpkgpm.cc
@@ -1416,6 +1416,15 @@ static bool ItemIsEssential(pkgDPkgPM::Item const &I)
       return true;
    return (I.Pkg->Flags & pkgCache::Flag::Essential) != 0;
 }
+static bool ItemIsProtected(pkgDPkgPM::Item const &I)
+{
+   static auto const cachegen = _config->Find("pkgCacheGen::Protected");
+   if (cachegen == "none" || cachegen == "native")
+      return true;
+   if (unlikely(I.Pkg.end()))
+      return true;
+   return (I.Pkg->Flags & pkgCache::Flag::Important) != 0;
+}
 bool pkgDPkgPM::ExpandPendingCalls(std::vector<Item> &List, pkgDepCache &Cache)
 {
    {
@@ -1712,6 +1721,7 @@ bool pkgDPkgPM::Go(APT::Progress::PackageManager *progress)
    OpenLog();
 
    bool dpkgMultiArch = _system->MultiArchSupported();
+   bool dpkgProtectedField = debSystem::AssertFeature("protected-field");
 
    // start pty magic before the loop
    StartPtyMagic();
@@ -1780,6 +1790,10 @@ bool pkgDPkgPM::Go(APT::Progress::PackageManager *progress)
 	 {
 	    ADDARGC("--force-remove-essential");
 	 }
+	 if (dpkgProtectedField && std::any_of(I, J, ItemIsProtected))
+	 {
+	    ADDARGC("--force-remove-protected");
+	 }
 	 ADDARGC("--remove");
 	 break;
 
diff --git a/apt-pkg/tagfile-keys.list b/apt-pkg/tagfile-keys.list
index a979a404b..a16bc686a 100644
--- a/apt-pkg/tagfile-keys.list
+++ b/apt-pkg/tagfile-keys.list
@@ -48,6 +48,7 @@ Package-Revision
 Package-Type
 Pre-Depends
 Priority
+Protected
 Provides
 Recommended
 Recommends
diff --git a/apt-pkg/tagfile-order.c b/apt-pkg/tagfile-order.c
index 4c2068c00..bb199b32e 100644
--- a/apt-pkg/tagfile-order.c
+++ b/apt-pkg/tagfile-order.c
@@ -11,7 +11,7 @@ static const char *iTFRewritePackageOrder[] = {
    "Architecture",
    "Subarchitecture", // Used only by d-i
    "Version",
-   "Revision",	 // Obsolete (warning in dpkg)
+   "Revision",	       // Obsolete (warning in dpkg)
    "Package-Revision", // Obsolete (warning in dpkg)
    "Package_Revision", // Obsolete (warning in dpkg)
    "Kernel-Version",   // Used only by d-i
@@ -23,6 +23,7 @@ static const char *iTFRewritePackageOrder[] = {
    "Priority",
    "Class", // dpkg nickname for Priority
    "Build-Essential",
+   "Protected",
    "Essential",
    "Installer-Menu-Item", // Used only by d-i
    "Section",