Propagate Protected flag to single-option dependencies

If a package is protected and has a dependency satisfied only by a single
package (or conflicts with a package) this package must be part of the
solution and so we can help later actions not exploring dead ends by
propagating the protected flag to these "pseudo-protected" packages.

An (obscure) bug this can help prevent (to some extend) is shown in
test-apt-never-markauto-sections by not causing irreversible autobit
transfers.

As a sideeffect it seems also to help our crude ShowBroken to display
slightly more helpful messages involving the packages which are actually
in conflict.

1 files changed, 1 insertions, 1 deletions

diff --git a/apt-pkg/depcache.h b/apt-pkg/depcache.h
index 669514e3f..339686b95 100644
--- a/apt-pkg/depcache.h
+++ b/apt-pkg/depcache.h
@@ -521,7 +521,7 @@ class APT_PUBLIC pkgDepCache : protected pkgCache::Namespace
    APT_HIDDEN bool MarkInstall_StateChange(PkgIterator const &Pkg, bool AutoInst, bool FromUser);
    APT_HIDDEN bool MarkInstall_CollectDependencies(pkgCache::VerIterator const &PV, std::vector<pkgCache::DepIterator> &toInstall, std::vector<pkgCache::DepIterator> &toRemove);
    APT_HIDDEN bool MarkInstall_RemoveConflictsIfNotUpgradeable(pkgCache::VerIterator const &PV, unsigned long Depth, std::vector<pkgCache::DepIterator> &toRemove, APT::PackageVector &toUpgrade);
-   APT_HIDDEN bool MarkInstall_UpgradeOrRemoveConflicts(unsigned long Depth, bool const ForceImportantDeps, APT::PackageVector &toUpgrade);
+   APT_HIDDEN bool MarkInstall_UpgradeOrRemoveConflicts(PkgIterator const &Pkg, unsigned long Depth, bool const ForceImportantDeps, APT::PackageVector &toUpgrade);
    APT_HIDDEN bool MarkInstall_InstallDependencies(PkgIterator const &Pkg, unsigned long Depth, bool const ForceImportantDeps, std::vector<pkgCache::DepIterator> &toInstall, APT::PackageVector *const toMoveAuto);
 };