solver3: Do not prefer new installs over manually installed obsoletes

Only move obsolete packages last that are automatically installed,
as we don't want to remove manually installed obsolete packages.

Add some missing const annotations to the operator[] arguments as
well that were needed.

LP: #2100247

1 files changed, 8 insertions, 5 deletions

diff --git a/apt-pkg/solver3.h b/apt-pkg/solver3.h
index 9d4a195ec..b7000c52e 100644
--- a/apt-pkg/solver3.h
+++ b/apt-pkg/solver3.h
@@ -146,21 +146,21 @@ class Solver
    ContiguousCacheMap<pkgCache::Version, State> verStates;
 
    // \brief Helper function for safe access to package state.
-   inline State &operator[](pkgCache::Package *P)
+   inline State &operator[](const pkgCache::Package *P)
    {
       return pkgStates[P];
    }
-   inline const State &operator[](pkgCache::Package *P) const
+   inline const State &operator[](const pkgCache::Package *P) const
    {
       return pkgStates[P];
    }
 
    // \brief Helper function for safe access to version state.
-   inline State &operator[](pkgCache::Version *V)
+   inline State &operator[](const pkgCache::Version *V)
    {
       return verStates[V];
    }
-   inline const State &operator[](pkgCache::Version *V) const
+   inline const State &operator[](const pkgCache::Version *V) const
    {
       return verStates[V];
    }
@@ -169,7 +169,9 @@ class Solver
    inline const State &operator[](Var r) const;
 
    mutable FastContiguousCacheMap<pkgCache::Package, char> pkgObsolete;
-   bool Obsolete(pkgCache::PkgIterator pkg) const;
+   // \brief Check if package is obsolete.
+   // \param AllowManual controls whether manual packages can be obsolete
+   bool Obsolete(pkgCache::PkgIterator pkg, bool AllowManual=false) const;
    bool ObsoletedByNewerSourceVersion(pkgCache::VerIterator cand) const;
 
    mutable FastContiguousCacheMap<pkgCache::Version, short> priorities;
@@ -471,6 +473,7 @@ struct APT::Solver::State
    struct
    {
       bool discovered{};
+      bool manual{};
    } flags;
 
    static_assert(sizeof(flags) <= sizeof(int));