]> git.saurik.com Git - apt.git/blobdiff - apt-pkg/algorithms.cc
fix and document on the fly compressor config
[apt.git] / apt-pkg / algorithms.cc
index 8644a81388dfff59a409c5befc865b7c11298a95..d202951a95c35012e121e93415633c4d64837bcf 100644 (file)
 #include <apt-pkg/algorithms.h>
 #include <apt-pkg/error.h>
 #include <apt-pkg/configuration.h>
-#include <apt-pkg/version.h>
-#include <apt-pkg/sptr.h>
-#include <apt-pkg/acquire-item.h>
 #include <apt-pkg/edsp.h>
-#include <apt-pkg/sourcelist.h>
-#include <apt-pkg/fileutl.h>
-#include <apt-pkg/progress.h>
-
-#include <sys/types.h>
+#include <apt-pkg/depcache.h>
+#include <apt-pkg/packagemanager.h>
+#include <apt-pkg/pkgcache.h>
+#include <apt-pkg/cacheiterators.h>
+#include <apt-pkg/prettyprinters.h>
+
+#include <string.h>
+#include <string>
 #include <cstdlib>
-#include <algorithm>
 #include <iostream>
-#include <stdio.h>
 
 #include <apti18n.h>
                                                                        /*}}}*/
 using namespace std;
 
-pkgProblemResolver *pkgProblemResolver::This = 0;
-
 // Simulate::Simulate - Constructor                                    /*{{{*/
 // ---------------------------------------------------------------------
 /* The legacy translations here of input Pkg iterators is obsolete, 
    this is not necessary since the pkgCaches are fully shared now. */
 pkgSimulate::pkgSimulate(pkgDepCache *Cache) : pkgPackageManager(Cache),
-                           iPolicy(Cache),
+                           d(NULL), iPolicy(Cache),
                            Sim(&Cache->GetCache(),&iPolicy),
                            group(Sim)
 {
@@ -363,13 +359,11 @@ pkgProblemResolver::~pkgProblemResolver()
 // ProblemResolver::ScoreSort - Sort the list by score                 /*{{{*/
 // ---------------------------------------------------------------------
 /* */
-int pkgProblemResolver::ScoreSort(const void *a,const void *b)
+int pkgProblemResolver::ScoreSort(Package const *A,Package const *B)
 {
-   Package const **A = (Package const **)a;
-   Package const **B = (Package const **)b;
-   if (This->Scores[(*A)->ID] > This->Scores[(*B)->ID])
+   if (Scores[A->ID] > Scores[B->ID])
       return -1;
-   if (This->Scores[(*A)->ID] < This->Scores[(*B)->ID])
+   if (Scores[A->ID] < Scores[B->ID])
       return 1;
    return 0;
 }
@@ -394,8 +388,18 @@ void pkgProblemResolver::MakeScores()
    };
    int PrioEssentials = _config->FindI("pkgProblemResolver::Scores::Essentials",100);
    int PrioInstalledAndNotObsolete = _config->FindI("pkgProblemResolver::Scores::NotObsolete",1);
-   int PrioDepends = _config->FindI("pkgProblemResolver::Scores::Depends",1);
-   int PrioRecommends = _config->FindI("pkgProblemResolver::Scores::Recommends",1);
+   int DepMap[] = {
+      0,
+      _config->FindI("pkgProblemResolver::Scores::Depends",1),
+      _config->FindI("pkgProblemResolver::Scores::PreDepends",1),
+      _config->FindI("pkgProblemResolver::Scores::Suggests",0),
+      _config->FindI("pkgProblemResolver::Scores::Recommends",1),
+      _config->FindI("pkgProblemResolver::Scores::Conflicts",-1),
+      _config->FindI("pkgProblemResolver::Scores::Replaces",0),
+      _config->FindI("pkgProblemResolver::Scores::Obsoletes",0),
+      _config->FindI("pkgProblemResolver::Scores::Breaks",-1),
+      _config->FindI("pkgProblemResolver::Scores::Enhances",0)
+   };
    int AddProtected = _config->FindI("pkgProblemResolver::Scores::AddProtected",10000);
    int AddEssential = _config->FindI("pkgProblemResolver::Scores::AddEssential",5000);
 
@@ -408,8 +412,15 @@ void pkgProblemResolver::MakeScores()
          << "  Extra => " << PrioMap[pkgCache::State::Extra] << endl
          << "  Essentials => " << PrioEssentials << endl
          << "  InstalledAndNotObsolete => " << PrioInstalledAndNotObsolete << endl
-         << "  Depends => " << PrioDepends << endl
-         << "  Recommends => " << PrioRecommends << endl
+         << "  Pre-Depends => " << DepMap[pkgCache::Dep::PreDepends] << endl
+         << "  Depends => " << DepMap[pkgCache::Dep::Depends] << endl
+         << "  Recommends => " << DepMap[pkgCache::Dep::Recommends] << endl
+         << "  Suggests => " << DepMap[pkgCache::Dep::Suggests] << endl
+         << "  Conflicts => " << DepMap[pkgCache::Dep::Conflicts] << endl
+         << "  Breaks => " << DepMap[pkgCache::Dep::DpkgBreaks] << endl
+         << "  Replaces => " << DepMap[pkgCache::Dep::Replaces] << endl
+         << "  Obsoletes => " << DepMap[pkgCache::Dep::Obsoletes] << endl
+         << "  Enhances => " << DepMap[pkgCache::Dep::Enhances] << endl
          << "  AddProtected => " << AddProtected << endl
          << "  AddEssential => " << AddEssential << endl;
 
@@ -424,42 +435,44 @@ void pkgProblemResolver::MakeScores()
       /* This is arbitrary, it should be high enough to elevate an
          essantial package above most other packages but low enough
         to allow an obsolete essential packages to be removed by
-        a conflicts on a powerfull normal package (ie libc6) */
+        a conflicts on a powerful normal package (ie libc6) */
       if ((I->Flags & pkgCache::Flag::Essential) == pkgCache::Flag::Essential
          || (I->Flags & pkgCache::Flag::Important) == pkgCache::Flag::Important)
         Score += PrioEssentials;
 
-      // We transform the priority
-      if (Cache[I].InstVerIter(Cache)->Priority <= 5)
-        Score += PrioMap[Cache[I].InstVerIter(Cache)->Priority];
-      
+      pkgCache::VerIterator const InstVer = Cache[I].InstVerIter(Cache);
+      // We apply priorities only to downloadable packages, all others are prio:extra
+      // as an obsolete prio:standard package can't be that standard anymore…
+      if (InstVer->Priority <= pkgCache::State::Extra && InstVer.Downloadable() == true)
+        Score += PrioMap[InstVer->Priority];
+      else
+        Score += PrioMap[pkgCache::State::Extra];
+
       /* This helps to fix oddball problems with conflicting packages
-         on the same level. We enhance the score of installed packages 
-        if those are not obsolete
-      */
+        on the same level. We enhance the score of installed packages
+        if those are not obsolete */
       if (I->CurrentVer != 0 && Cache[I].CandidateVer != 0 && Cache[I].CandidateVerIter(Cache).Downloadable())
         Score += PrioInstalledAndNotObsolete;
-   }
 
-   // Now that we have the base scores we go and propogate dependencies
-   for (pkgCache::PkgIterator I = Cache.PkgBegin(); I.end() == false; ++I)
-   {
-      if (Cache[I].InstallVer == 0)
-        continue;
-      
-      for (pkgCache::DepIterator D = Cache[I].InstVerIter(Cache).DependsList(); D.end() == false; ++D)
+      // propagate score points along dependencies
+      for (pkgCache::DepIterator D = InstVer.DependsList(); D.end() == false; ++D)
       {
-        if (D->Type == pkgCache::Dep::Depends || 
-            D->Type == pkgCache::Dep::PreDepends)
-           Scores[D.TargetPkg()->ID] += PrioDepends;
-        else if (D->Type == pkgCache::Dep::Recommends)
-           Scores[D.TargetPkg()->ID] += PrioRecommends;
+        if (DepMap[D->Type] == 0)
+           continue;
+        pkgCache::PkgIterator const T = D.TargetPkg();
+        if (D->Version != 0)
+        {
+           pkgCache::VerIterator const IV = Cache[T].InstVerIter(Cache);
+           if (IV.end() == true || D.IsSatisfied(IV) == false)
+              continue;
+        }
+        Scores[T->ID] += DepMap[D->Type];
       }
-   }   
-   
+   }
+
    // Copy the scores to advoid additive looping
-   SPtrArray<int> OldScores = new int[Size];
-   memcpy(OldScores,Scores,sizeof(*Scores)*Size);
+   std::unique_ptr<int[]> OldScores(new int[Size]);
+   memcpy(OldScores.get(),Scores,sizeof(*Scores)*Size);
       
    /* Now we cause 1 level of dependency inheritance, that is we add the 
       score of the packages that depend on the target Package. This 
@@ -485,7 +498,7 @@ void pkgProblemResolver::MakeScores()
       }      
    }
 
-   /* Now we propogate along provides. This makes the packages that 
+   /* Now we propagate along provides. This makes the packages that
       provide important packages extremely important */
    for (pkgCache::PkgIterator I = Cache.PkgBegin(); I.end() == false; ++I)
    {
@@ -620,15 +633,11 @@ bool pkgProblemResolver::DoUpgrade(pkgCache::PkgIterator Pkg)
 }
                                                                        /*}}}*/
 // ProblemResolver::Resolve - calls a resolver to fix the situation    /*{{{*/
-// ---------------------------------------------------------------------
-/* */
-bool pkgProblemResolver::Resolve(bool BrokenFix)
+bool pkgProblemResolver::Resolve(bool BrokenFix, OpProgress * const Progress)
 {
    std::string const solver = _config->Find("APT::Solver", "internal");
-   if (solver != "internal") {
-      OpTextProgress Prog(*_config);
-      return EDSP::ResolveExternal(solver.c_str(), Cache, false, false, false, &Prog);
-   }
+   if (solver != "internal")
+      return EDSP::ResolveExternal(solver.c_str(), Cache, 0, Progress);
    return ResolveInternal(BrokenFix);
 }
                                                                        /*}}}*/
@@ -640,7 +649,7 @@ bool pkgProblemResolver::Resolve(bool BrokenFix)
    adjusting the package will inflict. 
       
    It goes from highest score to lowest and corrects all of the breaks by 
-   keeping or removing the dependant packages. If that fails then it removes
+   keeping or removing the dependent packages. If that fails then it removes
    the package itself and goes on. The routine should be able to intelligently
    go from any broken state to a fixed state. 
  
@@ -688,21 +697,21 @@ bool pkgProblemResolver::ResolveInternal(bool const BrokenFix)
       operates from highest score to lowest. This prevents problems when
       high score packages cause the removal of lower score packages that
       would cause the removal of even lower score packages. */
-   SPtrArray<pkgCache::Package *> PList = new pkgCache::Package *[Size];
-   pkgCache::Package **PEnd = PList;
+   std::unique_ptr<pkgCache::Package *[]> PList(new pkgCache::Package *[Size]);
+   pkgCache::Package **PEnd = PList.get();
    for (pkgCache::PkgIterator I = Cache.PkgBegin(); I.end() == false; ++I)
       *PEnd++ = I;
-   This = this;
-   qsort(PList,PEnd - PList,sizeof(*PList),&ScoreSort);
+
+   std::sort(PList.get(), PEnd, [this](Package *a, Package *b) { return ScoreSort(a, b) < 0; });
 
    if (_config->FindB("Debug::pkgProblemResolver::ShowScores",false) == true)
    {
       clog << "Show Scores" << endl;
-      for (pkgCache::Package **K = PList; K != PEnd; K++)
+      for (pkgCache::Package **K = PList.get(); K != PEnd; K++)
          if (Scores[(*K)->ID] != 0)
          {
            pkgCache::PkgIterator Pkg(Cache,*K);
-           clog << Scores[(*K)->ID] << ' ' << Pkg << std::endl;
+           clog << Scores[(*K)->ID] << ' ' << APT::PrettyPkg(&Cache, Pkg) << std::endl;
          }
    }
 
@@ -717,10 +726,11 @@ bool pkgProblemResolver::ResolveInternal(bool const BrokenFix)
       changing a breaks c) */
    bool Change = true;
    bool const TryFixByInstall = _config->FindB("pkgProblemResolver::FixByInstall", true);
+   std::vector<PackageKill> KillList;
    for (int Counter = 0; Counter != 10 && Change == true; Counter++)
    {
       Change = false;
-      for (pkgCache::Package **K = PList; K != PEnd; K++)
+      for (pkgCache::Package **K = PList.get(); K != PEnd; K++)
       {
         pkgCache::PkgIterator I(Cache,*K);
 
@@ -756,15 +766,15 @@ bool pkgProblemResolver::ResolveInternal(bool const BrokenFix)
            continue;
         
         if (Debug == true)
-           clog << "Investigating (" << Counter << ") " << I << endl;
+           clog << "Investigating (" << Counter << ") " << APT::PrettyPkg(&Cache, I) << endl;
         
         // Isolate the problem dependency
-        PackageKill KillList[100];
-        PackageKill *LEnd = KillList;
         bool InOr = false;
         pkgCache::DepIterator Start;
         pkgCache::DepIterator End;
-        PackageKill *OldEnd = LEnd;
+        size_t OldSize = 0;
+
+        KillList.resize(0);
         
         enum {OrRemove,OrKeep} OrOp = OrRemove;
         for (pkgCache::DepIterator D = Cache[I].InstVerIter(Cache).DependsList();
@@ -774,7 +784,7 @@ bool pkgProblemResolver::ResolveInternal(bool const BrokenFix)
            if (Start == End)
            {
               // Decide what to do
-              if (InOr == true && OldEnd == LEnd)
+              if (InOr == true && OldSize == KillList.size())
               {
                  if (OrOp == OrRemove)
                  {
@@ -808,7 +818,7 @@ bool pkgProblemResolver::ResolveInternal(bool const BrokenFix)
                  continue;
 
               InOr = Start != End;
-              OldEnd = LEnd;
+              OldSize = KillList.size();
            }
            else
             {
@@ -826,13 +836,13 @@ bool pkgProblemResolver::ResolveInternal(bool const BrokenFix)
            }
            
            if (Debug == true)
-              clog << "Broken " << Start << endl;
+              clog << "Broken " << APT::PrettyDep(&Cache, Start) << endl;
 
            /* Look across the version list. If there are no possible
               targets then we keep the package and bail. This is necessary
-              if a package has a dep on another package that cant be found */
-           SPtrArray<pkgCache::Version *> VList = Start.AllTargets();
-           if (*VList == 0 && (Flags[I->ID] & Protected) != Protected &&
+              if a package has a dep on another package that can't be found */
+           std::unique_ptr<pkgCache::Version *[]> VList(Start.AllTargets());
+           if (VList[0] == 0 && (Flags[I->ID] & Protected) != Protected &&
                Start.IsNegative() == false &&
                Cache[I].NowBroken() == false)
            {          
@@ -849,7 +859,7 @@ bool pkgProblemResolver::ResolveInternal(bool const BrokenFix)
            }
            
            bool Done = false;
-           for (pkgCache::Version **V = VList; *V != 0; V++)
+           for (pkgCache::Version **V = VList.get(); *V != 0; V++)
            {
               pkgCache::VerIterator Ver(Cache,*V);
               pkgCache::PkgIterator Pkg = Ver.ParentPkg();
@@ -869,8 +879,8 @@ bool pkgProblemResolver::ResolveInternal(bool const BrokenFix)
                }
 
               if (Debug == true)
-                 clog << "  Considering " << Pkg.FullName(false) << ' ' << (int)Scores[Pkg->ID] <<
-                 " as a solution to " << I.FullName(false) << ' ' << (int)Scores[I->ID] << endl;
+                 clog << "  Considering " << Pkg.FullName(false) << ' ' << Scores[Pkg->ID] <<
+                 " as a solution to " << I.FullName(false) << ' ' << Scores[I->ID] << endl;
 
               /* Try to fix the package under consideration rather than
                  fiddle with the VList package */
@@ -925,7 +935,7 @@ bool pkgProblemResolver::ResolveInternal(bool const BrokenFix)
                                 Start.TargetPkg()->CurrentVer == 0 &&
                                 Cache[Start.TargetPkg()].Delete() == false &&
                                 (Flags[Start.TargetPkg()->ID] & ToRemove) != ToRemove &&
-                                Cache.GetCandidateVer(Start.TargetPkg()).end() == false)
+                                Cache.GetCandidateVersion(Start.TargetPkg()).end() == false)
                        {
                           /* Before removing or keeping the package with the broken dependency
                              try instead to install the first not previously installed package
@@ -933,7 +943,7 @@ bool pkgProblemResolver::ResolveInternal(bool const BrokenFix)
                              is removed by the resolver because of a conflict or alike but it is
                              dangerous as it could trigger new breaks/conflicts… */
                           if (Debug == true)
-                             clog << "  Try Installing " << Start.TargetPkg() << " before changing " << I.FullName(false) << std::endl;
+                             clog << "  Try Installing " << APT::PrettyPkg(&Cache, Start.TargetPkg()) << " before changing " << I.FullName(false) << std::endl;
                           unsigned long const OldBroken = Cache.BrokenCount();
                           Cache.MarkInstall(Start.TargetPkg(), true, 1, false);
                           // FIXME: we should undo the complete MarkInstall process here
@@ -971,10 +981,8 @@ bool pkgProblemResolver::ResolveInternal(bool const BrokenFix)
                
                  if (Debug == true)
                     clog << "  Added " << Pkg.FullName(false) << " to the remove list" << endl;
-                 
-                 LEnd->Pkg = Pkg;
-                 LEnd->Dep = End;
-                 LEnd++;
+
+                 KillList.push_back({Pkg, End});
                  
                  if (Start.IsNegative() == false)
                     break;
@@ -1024,7 +1032,7 @@ bool pkgProblemResolver::ResolveInternal(bool const BrokenFix)
         // Apply the kill list now
         if (Cache[I].InstallVer != 0)
         {
-           for (PackageKill *J = KillList; J != LEnd; J++)
+           for (auto J = KillList.begin(); J != KillList.end(); J++)
            {
               Change = true;
               if ((Cache[J->Dep] & pkgDepCache::DepGNow) == 0)
@@ -1101,7 +1109,7 @@ bool pkgProblemResolver::InstOrNewPolicyBroken(pkgCache::PkgIterator I)
    if (Cache[I].InstBroken() == true)
    {
       if (Debug == true)
-        std::clog << "  Dependencies are not satisfied for " << I << std::endl;
+        std::clog << "  Dependencies are not satisfied for " << APT::PrettyPkg(&Cache, I) << std::endl;
       return true;
    }
 
@@ -1110,7 +1118,7 @@ bool pkgProblemResolver::InstOrNewPolicyBroken(pkgCache::PkgIterator I)
        Cache[I].InstPolicyBroken() == true)
    {
       if (Debug == true)
-        std::clog << "  Policy breaks with upgrade of " << I << std::endl;
+        std::clog << "  Policy breaks with upgrade of " << APT::PrettyPkg(&Cache, I) << std::endl;
       return true;
    }
 
@@ -1122,13 +1130,13 @@ bool pkgProblemResolver::InstOrNewPolicyBroken(pkgCache::PkgIterator I)
 /* This is the work horse of the soft upgrade routine. It is very gental 
    in that it does not install or remove any packages. It is assumed that the
    system was non-broken previously. */
-bool pkgProblemResolver::ResolveByKeep()
+bool pkgProblemResolver::ResolveByKeep(OpProgress * const Progress)
 {
    std::string const solver = _config->Find("APT::Solver", "internal");
-   if (solver != "internal") {
-      OpTextProgress Prog(*_config);
-      return EDSP::ResolveExternal(solver.c_str(), Cache, true, false, false, &Prog);
-   }
+   if (solver != "internal")
+      return EDSP::ResolveExternal(solver.c_str(), Cache,
+           EDSP::Request::UPGRADE_ALL | EDSP::Request::FORBID_NEW_INSTALL | EDSP::Request::FORBID_REMOVE,
+           Progress);
    return ResolveByKeepInternal();
 }
                                                                        /*}}}*/
@@ -1153,8 +1161,9 @@ bool pkgProblemResolver::ResolveByKeepInternal()
    pkgCache::Package **PEnd = PList;
    for (pkgCache::PkgIterator I = Cache.PkgBegin(); I.end() == false; ++I)
       *PEnd++ = I;
-   This = this;
-   qsort(PList,PEnd - PList,sizeof(*PList),&ScoreSort);
+
+   std::sort(PList,PEnd,[this](Package *a, Package *b) { return ScoreSort(a, b) < 0; });
+
 
    if (_config->FindB("Debug::pkgProblemResolver::ShowScores",false) == true)
    {
@@ -1163,7 +1172,7 @@ bool pkgProblemResolver::ResolveByKeepInternal()
          if (Scores[(*K)->ID] != 0)
          {
            pkgCache::PkgIterator Pkg(Cache,*K);
-           clog << Scores[(*K)->ID] << ' ' << Pkg << std::endl;
+           clog << Scores[(*K)->ID] << ' ' << APT::PrettyPkg(&Cache, Pkg) << std::endl;
          }
    }
 
@@ -1183,7 +1192,7 @@ bool pkgProblemResolver::ResolveByKeepInternal()
          continue;
 
       /* Keep the package. If this works then great, otherwise we have
-                to be significantly more agressive and manipulate its dependencies */
+        to be significantly more aggressive and manipulate its dependencies */
       if ((Flags[I->ID] & Protected) == 0)
       {
         if (Debug == true)
@@ -1218,11 +1227,11 @@ bool pkgProblemResolver::ResolveByKeepInternal()
         while (true)
         {
            if (Debug == true)
-              clog << "Package " << I.FullName(false) << " " << Start << endl;
+              clog << "Package " << I.FullName(false) << " " << APT::PrettyDep(&Cache, Start) << endl;
 
            // Look at all the possible provides on this package
-           SPtrArray<pkgCache::Version *> VList = Start.AllTargets();
-           for (pkgCache::Version **V = VList; *V != 0; V++)
+           std::unique_ptr<pkgCache::Version *[]> VList(Start.AllTargets());
+           for (pkgCache::Version **V = VList.get(); *V != 0; V++)
            {
               pkgCache::VerIterator Ver(Cache,*V);
               pkgCache::PkgIterator Pkg = Ver.ParentPkg();
@@ -1304,36 +1313,46 @@ void pkgProblemResolver::InstallProtect()
 // ---------------------------------------------------------------------
 /* This is ment to be used in conjunction with AllTargets to get a list 
    of versions ordered by preference. */
-static pkgCache *PrioCache;
-static int PrioComp(const void *A,const void *B)
-{
-   pkgCache::VerIterator L(*PrioCache,*(pkgCache::Version **)A);
-   pkgCache::VerIterator R(*PrioCache,*(pkgCache::Version **)B);
-   
-   if ((L.ParentPkg()->Flags & pkgCache::Flag::Essential) == pkgCache::Flag::Essential &&
-       (R.ParentPkg()->Flags & pkgCache::Flag::Essential) != pkgCache::Flag::Essential)
-     return 1;
-   if ((L.ParentPkg()->Flags & pkgCache::Flag::Essential) != pkgCache::Flag::Essential &&
-       (R.ParentPkg()->Flags & pkgCache::Flag::Essential) == pkgCache::Flag::Essential)
-     return -1;
-
-   if ((L.ParentPkg()->Flags & pkgCache::Flag::Important) == pkgCache::Flag::Important &&
-       (R.ParentPkg()->Flags & pkgCache::Flag::Important) != pkgCache::Flag::Important)
-     return 1;
-   if ((L.ParentPkg()->Flags & pkgCache::Flag::Important) != pkgCache::Flag::Important &&
-       (R.ParentPkg()->Flags & pkgCache::Flag::Important) == pkgCache::Flag::Important)
-     return -1;
-   
-   if (L->Priority != R->Priority)
-      return R->Priority - L->Priority;
-   return strcmp(L.ParentPkg().Name(),R.ParentPkg().Name());
-}
+
+struct PrioComp {
+   pkgCache &PrioCache;
+
+   explicit PrioComp(pkgCache &PrioCache) : PrioCache(PrioCache) {
+   }
+
+   bool operator() (pkgCache::Version * const &A, pkgCache::Version * const &B) {
+      return compare(A, B) < 0;
+   }
+
+   int compare(pkgCache::Version * const &A, pkgCache::Version * const &B) {
+      pkgCache::VerIterator L(PrioCache,A);
+      pkgCache::VerIterator R(PrioCache,B);
+
+      if ((L.ParentPkg()->Flags & pkgCache::Flag::Essential) == pkgCache::Flag::Essential &&
+         (R.ParentPkg()->Flags & pkgCache::Flag::Essential) != pkgCache::Flag::Essential)
+       return 1;
+      if ((L.ParentPkg()->Flags & pkgCache::Flag::Essential) != pkgCache::Flag::Essential &&
+         (R.ParentPkg()->Flags & pkgCache::Flag::Essential) == pkgCache::Flag::Essential)
+       return -1;
+
+      if ((L.ParentPkg()->Flags & pkgCache::Flag::Important) == pkgCache::Flag::Important &&
+         (R.ParentPkg()->Flags & pkgCache::Flag::Important) != pkgCache::Flag::Important)
+       return 1;
+      if ((L.ParentPkg()->Flags & pkgCache::Flag::Important) != pkgCache::Flag::Important &&
+         (R.ParentPkg()->Flags & pkgCache::Flag::Important) == pkgCache::Flag::Important)
+       return -1;
+
+      if (L->Priority != R->Priority)
+        return R->Priority - L->Priority;
+      return strcmp(L.ParentPkg().Name(),R.ParentPkg().Name());
+   }
+};
+
 void pkgPrioSortList(pkgCache &Cache,pkgCache::Version **List)
 {
    unsigned long Count = 0;
-   PrioCache = &Cache;
    for (pkgCache::Version **I = List; *I != 0; I++)
       Count++;
-   qsort(List,Count,sizeof(*List),PrioComp);
+   std::sort(List,List+Count,PrioComp(Cache));
 }
                                                                        /*}}}*/