Merging upstream version 2.9.5.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 46 insertions, 6 deletions

diff --git a/apt-pkg/solver3.h b/apt-pkg/solver3.h
index cf2fb2e..9a9d67a 100644
--- a/apt-pkg/solver3.h
+++ b/apt-pkg/solver3.h
@@ -32,10 +32,46 @@ class Solver
    enum class Decision : uint16_t;
    enum class Hint : uint16_t;
    struct Reason;
+   struct CompareProviders3;
    template <typename T>
    struct State;
    struct Work;
 
+   // \brief Groups of works, these are ordered.
+   //
+   // Later items will be skipped if they are optional, or we will when backtracking,
+   // try a different choice for them.
+   enum class Group : uint8_t
+   {
+      HoldOrDelete,
+      NewUnsatRecommends,
+
+      // Satisfying dependencies on entirely new packages first is a good idea because
+      // it may contain replacement packages like libfoo1t64 whereas we later will see
+      // Depends: libfoo1 where libfoo1t64 Provides libfoo1 and we'd have to choose.
+      SatisfyNew,
+      Satisfy,
+      // On a similar note as for SatisfyNew, if the dependency contains obsolete packages
+      // try it last.
+      SatisfyObsolete,
+
+      // My intuition tells me that we should try to schedule upgrades first, then
+      // any non-obsolete installed packages, and only finally obsolete ones, such
+      // that newer packages guide resolution of dependencies for older ones, they
+      // may have more stringent dependencies, like a (>> 2) whereas an obsolete
+      // package may have a (>> 1), for example.
+      UpgradeManual,
+      InstallManual,
+      ObsoleteManual,
+
+      // Automatically installed packages must come last in the group, this allows
+      // us to see if they were installed as a dependency of a manually installed package,
+      // allowing a simple implementation of an autoremoval code.
+      UpgradeAuto,
+      KeepAuto,
+      ObsoleteAuto
+   };
+
    // \brief Type to record depth at. This may very well be a 16-bit
    // unsigned integer, then change Solver::State::Decision to be a
    // uint16_t class enum as well to get a more compact space.
@@ -68,6 +104,9 @@ class Solver
       return verStates[V->ID];
    }
 
+   std::vector<char> verObsolete;
+   bool Obsolete(pkgCache::VerIterator ver);
+
    // \brief Heap of the remaining work.
    //
    // We are using an std::vector with std::make_heap(), std::push_heap(),
@@ -131,13 +170,13 @@ class Solver
    Solver(pkgCache &Cache, pkgDepCache::Policy &Policy);
 
    // \brief Mark the package for install. This is annoying as it incurs a decision
-   bool Install(pkgCache::PkgIterator Pkg, Reason reason);
+   bool Install(pkgCache::PkgIterator Pkg, Reason reason, Group group);
    // \brief Install a version.
-   bool Install(pkgCache::VerIterator Ver, Reason reason);
+   bool Install(pkgCache::VerIterator Ver, Reason reason, Group group);
    // \brief Do not install this package
-   bool Reject(pkgCache::PkgIterator Pkg, Reason reason);
+   bool Reject(pkgCache::PkgIterator Pkg, Reason reason, Group group);
    // \brief Do not install this version.
-   bool Reject(pkgCache::VerIterator Ver, Reason reason);
+   bool Reject(pkgCache::VerIterator Ver, Reason reason, Group group);
 
    // \brief Apply the selections from the dep cache to the solver
    bool FromDepCache(pkgDepCache &depcache);
@@ -203,7 +242,8 @@ struct APT::Solver::Work
    Reason reason;
    // \brief The depth at which the item has been added
    depth_type depth;
-
+   // \brief The group we are in
+   Group group;
    // \brief Possible solutions to this task, ordered in order of preference.
    std::vector<pkgCache::Version *> solutions{};
 
@@ -228,7 +268,7 @@ struct APT::Solver::Work
    // \brief Dump the work item to std::cerr
    void Dump(pkgCache &cache);
 
-   inline Work(Reason reason, depth_type depth, bool optional = false, bool upgrade = false) : reason(reason), depth(depth), size(0), optional(optional), upgrade(upgrade), dirty(false) {}
+   inline Work(Reason reason, depth_type depth, Group group, bool optional = false, bool upgrade = false) : reason(reason), depth(depth), group(group), size(0), optional(optional), upgrade(upgrade), dirty(false) {}
 };
 
 // \brief This essentially describes the install state in RFC2119 terms.