apt-pkg/algorithms.cc

   1 // -*- mode: cpp; mode: fold -*-
   2 // Description                                                          /*{{{*/
   3 // $Id: algorithms.cc,v 1.44 2002/11/28 18:49:16 jgg Exp $
   4 /* ######################################################################
   5
   6    Algorithms - A set of misc algorithms
   7
   8    The pkgProblemResolver class has become insanely complex and
   9    very sophisticated, it handles every test case I have thrown at it
  10    to my satisfaction. Understanding exactly why all the steps the class
  11    does are required is difficult and changing though not very risky
  12    may result in other cases not working.
  13
  14    ##################################################################### */
  15                                                                         /*}}}*/
  16 // Include Files                                                        /*{{{*/
  17 #include <config.h>
  18
  19 #include <apt-pkg/algorithms.h>
  20 #include <apt-pkg/error.h>
  21 #include <apt-pkg/configuration.h>
  22 #include <apt-pkg/sptr.h>
  23 #include <apt-pkg/edsp.h>
  24 #include <apt-pkg/progress.h>
  25 #include <apt-pkg/depcache.h>
  26 #include <apt-pkg/packagemanager.h>
  27 #include <apt-pkg/pkgcache.h>
  28 #include <apt-pkg/cacheiterators.h>
  29
  30 #include <string.h>
  31 #include <string>
  32 #include <cstdlib>
  33 #include <iostream>
  34
  35 #include <apti18n.h>
  36                                                                         /*}}}*/
  37 using namespace std;
  38
  39 pkgProblemResolver *pkgProblemResolver::This = 0;
  40
  41 // Simulate::Simulate - Constructor                                     /*{{{*/
  42 // ---------------------------------------------------------------------
  43 /* The legacy translations here of input Pkg iterators is obsolete,
  44    this is not necessary since the pkgCaches are fully shared now. */
  45 pkgSimulate::pkgSimulate(pkgDepCache *Cache) : pkgPackageManager(Cache),
  46                             d(NULL), iPolicy(Cache),
  47                             Sim(&Cache->GetCache(),&iPolicy),
  48                             group(Sim)
  49 {
  50    Sim.Init(0);
  51    Flags = new unsigned char[Cache->Head().PackageCount];
  52    memset(Flags,0,sizeof(*Flags)*Cache->Head().PackageCount);
  53
  54    // Fake a filename so as not to activate the media swapping
  55    string Jnk = "SIMULATE";
  56    for (unsigned int I = 0; I != Cache->Head().PackageCount; I++)
  57       FileNames[I] = Jnk;
  58 }
  59                                                                         /*}}}*/
  60 // Simulate::~Simulate - Destructor                                     /*{{{*/
  61 pkgSimulate::~pkgSimulate()
  62 {
  63    delete[] Flags;
  64 }
  65                                                                         /*}}}*/
  66 // Simulate::Describe - Describe a package                              /*{{{*/
  67 // ---------------------------------------------------------------------
  68 /* Parameter Current == true displays the current package version,
  69    Parameter Candidate == true displays the candidate package version */
  70 void pkgSimulate::Describe(PkgIterator Pkg,ostream &out,bool Current,bool Candidate)
  71 {
  72    VerIterator Ver(Sim);
  73
  74    out << Pkg.FullName(true);
  75
  76    if (Current == true)
  77    {
  78       Ver = Pkg.CurrentVer();
  79       if (Ver.end() == false)
  80          out << " [" << Ver.VerStr() << ']';
  81    }
  82
  83    if (Candidate == true)
  84    {
  85       Ver = Sim[Pkg].CandidateVerIter(Sim);
  86       if (Ver.end() == true)
  87          return;
  88
  89       out << " (" << Ver.VerStr() << ' ' << Ver.RelStr() << ')';
  90    }
  91 }
  92                                                                         /*}}}*/
  93 // Simulate::Install - Simulate unpacking of a package                  /*{{{*/
  94 // ---------------------------------------------------------------------
  95 /* */
  96 bool pkgSimulate::Install(PkgIterator iPkg,string /*File*/)
  97 {
  98    // Adapt the iterator
  99    PkgIterator Pkg = Sim.FindPkg(iPkg.Name(), iPkg.Arch());
 100    Flags[Pkg->ID] = 1;
 101
 102    cout << "Inst ";
 103    Describe(Pkg,cout,true,true);
 104    Sim.MarkInstall(Pkg,false);
 105
 106    // Look for broken conflicts+predepends.
 107    for (PkgIterator I = Sim.PkgBegin(); I.end() == false; ++I)
 108    {
 109       if (Sim[I].InstallVer == 0)
 110          continue;
 111
 112       for (DepIterator D = Sim[I].InstVerIter(Sim).DependsList(); D.end() == false;)
 113       {
 114          DepIterator Start;
 115          DepIterator End;
 116          D.GlobOr(Start,End);
 117          if (Start.IsNegative() == true ||
 118              End->Type == pkgCache::Dep::PreDepends)
 119          {
 120             if ((Sim[End] & pkgDepCache::DepGInstall) == 0)
 121             {
 122                cout << " [" << I.FullName(false) << " on " << Start.TargetPkg().FullName(false) << ']';
 123                if (Start->Type == pkgCache::Dep::Conflicts)
 124                   _error->Error("Fatal, conflicts violated %s",I.FullName(false).c_str());
 125             }
 126          }
 127       }
 128    }
 129
 130    if (Sim.BrokenCount() != 0)
 131       ShortBreaks();
 132    else
 133       cout << endl;
 134    return true;
 135 }
 136                                                                         /*}}}*/
 137 // Simulate::Configure - Simulate configuration of a Package            /*{{{*/
 138 // ---------------------------------------------------------------------
 139 /* This is not an acurate simulation of relatity, we should really not
 140    install the package.. For some investigations it may be necessary
 141    however. */
 142 bool pkgSimulate::Configure(PkgIterator iPkg)
 143 {
 144    // Adapt the iterator
 145    PkgIterator Pkg = Sim.FindPkg(iPkg.Name(), iPkg.Arch());
 146
 147    Flags[Pkg->ID] = 2;
 148
 149    if (Sim[Pkg].InstBroken() == true)
 150    {
 151       cout << "Conf " << Pkg.FullName(false) << " broken" << endl;
 152
 153       Sim.Update();
 154
 155       // Print out each package and the failed dependencies
 156       for (pkgCache::DepIterator D = Sim[Pkg].InstVerIter(Sim).DependsList(); D.end() == false; ++D)
 157       {
 158          if (Sim.IsImportantDep(D) == false ||
 159              (Sim[D] & pkgDepCache::DepInstall) != 0)
 160             continue;
 161
 162          if (D->Type == pkgCache::Dep::Obsoletes)
 163             cout << " Obsoletes:" << D.TargetPkg().FullName(false);
 164          else if (D->Type == pkgCache::Dep::Conflicts)
 165             cout << " Conflicts:" << D.TargetPkg().FullName(false);
 166          else if (D->Type == pkgCache::Dep::DpkgBreaks)
 167             cout << " Breaks:" << D.TargetPkg().FullName(false);
 168          else
 169             cout << " Depends:" << D.TargetPkg().FullName(false);
 170       }
 171       cout << endl;
 172
 173       _error->Error("Conf Broken %s",Pkg.FullName(false).c_str());
 174    }
 175    else
 176    {
 177       cout << "Conf ";
 178       Describe(Pkg,cout,false,true);
 179    }
 180
 181    if (Sim.BrokenCount() != 0)
 182       ShortBreaks();
 183    else
 184       cout << endl;
 185
 186    return true;
 187 }
 188                                                                         /*}}}*/
 189 // Simulate::Remove - Simulate the removal of a package                 /*{{{*/
 190 // ---------------------------------------------------------------------
 191 /* */
 192 bool pkgSimulate::Remove(PkgIterator iPkg,bool Purge)
 193 {
 194    // Adapt the iterator
 195    PkgIterator Pkg = Sim.FindPkg(iPkg.Name(), iPkg.Arch());
 196    if (Pkg.end() == true)
 197    {
 198       std::cerr << (Purge ? "Purg" : "Remv") << " invalid package " << iPkg.FullName() << std::endl;
 199       return false;
 200    }
 201
 202    Flags[Pkg->ID] = 3;
 203    Sim.MarkDelete(Pkg);
 204
 205    if (Purge == true)
 206       cout << "Purg ";
 207    else
 208       cout << "Remv ";
 209    Describe(Pkg,cout,true,false);
 210
 211    if (Sim.BrokenCount() != 0)
 212       ShortBreaks();
 213    else
 214       cout << endl;
 215
 216    return true;
 217 }
 218                                                                         /*}}}*/
 219 // Simulate::ShortBreaks - Print out a short line describing all breaks /*{{{*/
 220 // ---------------------------------------------------------------------
 221 /* */
 222 void pkgSimulate::ShortBreaks()
 223 {
 224    cout << " [";
 225    for (PkgIterator I = Sim.PkgBegin(); I.end() == false; ++I)
 226    {
 227       if (Sim[I].InstBroken() == true)
 228       {
 229          if (Flags[I->ID] == 0)
 230             cout << I.FullName(false) << ' ';
 231 /*       else
 232             cout << I.Name() << "! ";*/
 233       }
 234    }
 235    cout << ']' << endl;
 236 }
 237                                                                         /*}}}*/
 238 // ApplyStatus - Adjust for non-ok packages                             /*{{{*/
 239 // ---------------------------------------------------------------------
 240 /* We attempt to change the state of the all packages that have failed
 241    installation toward their real state. The ordering code will perform
 242    the necessary calculations to deal with the problems. */
 243 bool pkgApplyStatus(pkgDepCache &Cache)
 244 {
 245    pkgDepCache::ActionGroup group(Cache);
 246
 247    for (pkgCache::PkgIterator I = Cache.PkgBegin(); I.end() == false; ++I)
 248    {
 249       if (I->VersionList == 0)
 250          continue;
 251
 252       // Only choice for a ReInstReq package is to reinstall
 253       if (I->InstState == pkgCache::State::ReInstReq ||
 254           I->InstState == pkgCache::State::HoldReInstReq)
 255       {
 256          if (I->CurrentVer != 0 && I.CurrentVer().Downloadable() == true)
 257             Cache.MarkKeep(I, false, false);
 258          else
 259          {
 260             // Is this right? Will dpkg choke on an upgrade?
 261             if (Cache[I].CandidateVer != 0 &&
 262                  Cache[I].CandidateVerIter(Cache).Downloadable() == true)
 263                Cache.MarkInstall(I, false, 0, false);
 264             else
 265                return _error->Error(_("The package %s needs to be reinstalled, "
 266                                     "but I can't find an archive for it."),I.FullName(true).c_str());
 267          }
 268
 269          continue;
 270       }
 271
 272       switch (I->CurrentState)
 273       {
 274          /* This means installation failed somehow - it does not need to be
 275             re-unpacked (probably) */
 276          case pkgCache::State::UnPacked:
 277          case pkgCache::State::HalfConfigured:
 278          case pkgCache::State::TriggersAwaited:
 279          case pkgCache::State::TriggersPending:
 280          if ((I->CurrentVer != 0 && I.CurrentVer().Downloadable() == true) ||
 281              I.State() != pkgCache::PkgIterator::NeedsUnpack)
 282             Cache.MarkKeep(I, false, false);
 283          else
 284          {
 285             if (Cache[I].CandidateVer != 0 &&
 286                  Cache[I].CandidateVerIter(Cache).Downloadable() == true)
 287                Cache.MarkInstall(I, true, 0, false);
 288             else
 289                Cache.MarkDelete(I, false, 0, false);
 290          }
 291          break;
 292
 293          // This means removal failed
 294          case pkgCache::State::HalfInstalled:
 295          Cache.MarkDelete(I, false, 0, false);
 296          break;
 297
 298          default:
 299          if (I->InstState != pkgCache::State::Ok)
 300             return _error->Error("The package %s is not ok and I "
 301                                  "don't know how to fix it!",I.FullName(false).c_str());
 302       }
 303    }
 304    return true;
 305 }
 306                                                                         /*}}}*/
 307 // FixBroken - Fix broken packages                                      /*{{{*/
 308 // ---------------------------------------------------------------------
 309 /* This autoinstalls every broken package and then runs the problem resolver
 310    on the result. */
 311 bool pkgFixBroken(pkgDepCache &Cache)
 312 {
 313    pkgDepCache::ActionGroup group(Cache);
 314
 315    // Auto upgrade all broken packages
 316    for (pkgCache::PkgIterator I = Cache.PkgBegin(); I.end() == false; ++I)
 317       if (Cache[I].NowBroken() == true)
 318          Cache.MarkInstall(I, true, 0, false);
 319
 320    /* Fix packages that are in a NeedArchive state but don't have a
 321       downloadable install version */
 322    for (pkgCache::PkgIterator I = Cache.PkgBegin(); I.end() == false; ++I)
 323    {
 324       if (I.State() != pkgCache::PkgIterator::NeedsUnpack ||
 325           Cache[I].Delete() == true)
 326          continue;
 327
 328       if (Cache[I].InstVerIter(Cache).Downloadable() == false)
 329          continue;
 330
 331       Cache.MarkInstall(I, true, 0, false);
 332    }
 333
 334    pkgProblemResolver Fix(&Cache);
 335    return Fix.Resolve(true);
 336 }
 337                                                                         /*}}}*/
 338 // ProblemResolver::pkgProblemResolver - Constructor                    /*{{{*/
 339 // ---------------------------------------------------------------------
 340 /* */
 341 pkgProblemResolver::pkgProblemResolver(pkgDepCache *pCache) : d(NULL), Cache(*pCache)
 342 {
 343    // Allocate memory
 344    unsigned long Size = Cache.Head().PackageCount;
 345    Scores = new int[Size];
 346    Flags = new unsigned char[Size];
 347    memset(Flags,0,sizeof(*Flags)*Size);
 348
 349    // Set debug to true to see its decision logic
 350    Debug = _config->FindB("Debug::pkgProblemResolver",false);
 351 }
 352                                                                         /*}}}*/
 353 // ProblemResolver::~pkgProblemResolver - Destructor                    /*{{{*/
 354 // ---------------------------------------------------------------------
 355 /* */
 356 pkgProblemResolver::~pkgProblemResolver()
 357 {
 358    delete [] Scores;
 359    delete [] Flags;
 360 }
 361                                                                         /*}}}*/
 362 // ProblemResolver::ScoreSort - Sort the list by score                  /*{{{*/
 363 // ---------------------------------------------------------------------
 364 /* */
 365 int pkgProblemResolver::ScoreSort(const void *a,const void *b)
 366 {
 367    Package const **A = (Package const **)a;
 368    Package const **B = (Package const **)b;
 369    if (This->Scores[(*A)->ID] > This->Scores[(*B)->ID])
 370       return -1;
 371    if (This->Scores[(*A)->ID] < This->Scores[(*B)->ID])
 372       return 1;
 373    return 0;
 374 }
 375                                                                         /*}}}*/
 376 // ProblemResolver::MakeScores - Make the score table                   /*{{{*/
 377 // ---------------------------------------------------------------------
 378 /* */
 379 void pkgProblemResolver::MakeScores()
 380 {
 381    unsigned long Size = Cache.Head().PackageCount;
 382    memset(Scores,0,sizeof(*Scores)*Size);
 383
 384    // maps to pkgCache::State::VerPriority:
 385    //    Required Important Standard Optional Extra
 386    int PrioMap[] = {
 387       0,
 388       _config->FindI("pkgProblemResolver::Scores::Required",3),
 389       _config->FindI("pkgProblemResolver::Scores::Important",2),
 390       _config->FindI("pkgProblemResolver::Scores::Standard",1),
 391       _config->FindI("pkgProblemResolver::Scores::Optional",-1),
 392       _config->FindI("pkgProblemResolver::Scores::Extra",-2)
 393    };
 394    int PrioEssentials = _config->FindI("pkgProblemResolver::Scores::Essentials",100);
 395    int PrioInstalledAndNotObsolete = _config->FindI("pkgProblemResolver::Scores::NotObsolete",1);
 396    int DepMap[] = {
 397       0,
 398       _config->FindI("pkgProblemResolver::Scores::Depends",1),
 399       _config->FindI("pkgProblemResolver::Scores::PreDepends",1),
 400       _config->FindI("pkgProblemResolver::Scores::Suggests",0),
 401       _config->FindI("pkgProblemResolver::Scores::Recommends",1),
 402       _config->FindI("pkgProblemResolver::Scores::Conflicts",-1),
 403       _config->FindI("pkgProblemResolver::Scores::Replaces",0),
 404       _config->FindI("pkgProblemResolver::Scores::Obsoletes",0),
 405       _config->FindI("pkgProblemResolver::Scores::Breaks",-1),
 406       _config->FindI("pkgProblemResolver::Scores::Enhances",0)
 407    };
 408    int AddProtected = _config->FindI("pkgProblemResolver::Scores::AddProtected",10000);
 409    int AddEssential = _config->FindI("pkgProblemResolver::Scores::AddEssential",5000);
 410
 411    if (_config->FindB("Debug::pkgProblemResolver::ShowScores",false) == true)
 412       clog << "Settings used to calculate pkgProblemResolver::Scores::" << endl
 413          << "  Required => " << PrioMap[pkgCache::State::Required] << endl
 414          << "  Important => " << PrioMap[pkgCache::State::Important] << endl
 415          << "  Standard => " << PrioMap[pkgCache::State::Standard] << endl
 416          << "  Optional => " << PrioMap[pkgCache::State::Optional] << endl
 417          << "  Extra => " << PrioMap[pkgCache::State::Extra] << endl
 418          << "  Essentials => " << PrioEssentials << endl
 419          << "  InstalledAndNotObsolete => " << PrioInstalledAndNotObsolete << endl
 420          << "  Pre-Depends => " << DepMap[pkgCache::Dep::PreDepends] << endl
 421          << "  Depends => " << DepMap[pkgCache::Dep::Depends] << endl
 422          << "  Recommends => " << DepMap[pkgCache::Dep::Recommends] << endl
 423          << "  Suggests => " << DepMap[pkgCache::Dep::Suggests] << endl
 424          << "  Conflicts => " << DepMap[pkgCache::Dep::Conflicts] << endl
 425          << "  Breaks => " << DepMap[pkgCache::Dep::DpkgBreaks] << endl
 426          << "  Replaces => " << DepMap[pkgCache::Dep::Replaces] << endl
 427          << "  Obsoletes => " << DepMap[pkgCache::Dep::Obsoletes] << endl
 428          << "  Enhances => " << DepMap[pkgCache::Dep::Enhances] << endl
 429          << "  AddProtected => " << AddProtected << endl
 430          << "  AddEssential => " << AddEssential << endl;
 431
 432    // Generate the base scores for a package based on its properties
 433    for (pkgCache::PkgIterator I = Cache.PkgBegin(); I.end() == false; ++I)
 434    {
 435       if (Cache[I].InstallVer == 0)
 436          continue;
 437
 438       int &Score = Scores[I->ID];
 439
 440       /* This is arbitrary, it should be high enough to elevate an
 441          essantial package above most other packages but low enough
 442          to allow an obsolete essential packages to be removed by
 443          a conflicts on a powerful normal package (ie libc6) */
 444       if ((I->Flags & pkgCache::Flag::Essential) == pkgCache::Flag::Essential
 445           || (I->Flags & pkgCache::Flag::Important) == pkgCache::Flag::Important)
 446          Score += PrioEssentials;
 447
 448       pkgCache::VerIterator const InstVer = Cache[I].InstVerIter(Cache);
 449       // We apply priorities only to downloadable packages, all others are prio:extra
 450       // as an obsolete prio:standard package can't be that standard anymore…
 451       if (InstVer->Priority <= pkgCache::State::Extra && InstVer.Downloadable() == true)
 452          Score += PrioMap[InstVer->Priority];
 453       else
 454          Score += PrioMap[pkgCache::State::Extra];
 455
 456       /* This helps to fix oddball problems with conflicting packages
 457          on the same level. We enhance the score of installed packages
 458          if those are not obsolete */
 459       if (I->CurrentVer != 0 && Cache[I].CandidateVer != 0 && Cache[I].CandidateVerIter(Cache).Downloadable())
 460          Score += PrioInstalledAndNotObsolete;
 461
 462       // propagate score points along dependencies
 463       for (pkgCache::DepIterator D = InstVer.DependsList(); D.end() == false; ++D)
 464       {
 465          if (DepMap[D->Type] == 0)
 466             continue;
 467          pkgCache::PkgIterator const T = D.TargetPkg();
 468          if (D->Version != 0)
 469          {
 470             pkgCache::VerIterator const IV = Cache[T].InstVerIter(Cache);
 471             if (IV.end() == true || D.IsSatisfied(IV) == false)
 472                continue;
 473          }
 474          Scores[T->ID] += DepMap[D->Type];
 475       }
 476    }
 477
 478    // Copy the scores to advoid additive looping
 479    std::unique_ptr<int[]> OldScores(new int[Size]);
 480    memcpy(OldScores.get(),Scores,sizeof(*Scores)*Size);
 481
 482    /* Now we cause 1 level of dependency inheritance, that is we add the
 483       score of the packages that depend on the target Package. This
 484       fortifies high scoring packages */
 485    for (pkgCache::PkgIterator I = Cache.PkgBegin(); I.end() == false; ++I)
 486    {
 487       if (Cache[I].InstallVer == 0)
 488          continue;
 489
 490       for (pkgCache::DepIterator D = I.RevDependsList(); D.end() == false; ++D)
 491       {
 492          // Only do it for the install version
 493          if ((pkgCache::Version *)D.ParentVer() != Cache[D.ParentPkg()].InstallVer ||
 494              (D->Type != pkgCache::Dep::Depends &&
 495               D->Type != pkgCache::Dep::PreDepends &&
 496               D->Type != pkgCache::Dep::Recommends))
 497             continue;
 498
 499          // Do not propagate negative scores otherwise
 500          // an extra (-2) package might score better than an optional (-1)
 501          if (OldScores[D.ParentPkg()->ID] > 0)
 502              Scores[I->ID] += OldScores[D.ParentPkg()->ID];
 503       }
 504    }
 505
 506    /* Now we propagate along provides. This makes the packages that
 507       provide important packages extremely important */
 508    for (pkgCache::PkgIterator I = Cache.PkgBegin(); I.end() == false; ++I)
 509    {
 510       for (pkgCache::PrvIterator P = I.ProvidesList(); P.end() == false; ++P)
 511       {
 512          // Only do it once per package
 513          if ((pkgCache::Version *)P.OwnerVer() != Cache[P.OwnerPkg()].InstallVer)
 514             continue;
 515          Scores[P.OwnerPkg()->ID] += abs(Scores[I->ID] - OldScores[I->ID]);
 516       }
 517    }
 518
 519    /* Protected things are pushed really high up. This number should put them
 520       ahead of everything */
 521    for (pkgCache::PkgIterator I = Cache.PkgBegin(); I.end() == false; ++I)
 522    {
 523       if ((Flags[I->ID] & Protected) != 0)
 524          Scores[I->ID] += AddProtected;
 525       if ((I->Flags & pkgCache::Flag::Essential) == pkgCache::Flag::Essential ||
 526           (I->Flags & pkgCache::Flag::Important) == pkgCache::Flag::Important)
 527          Scores[I->ID] += AddEssential;
 528    }
 529 }
 530                                                                         /*}}}*/
 531 // ProblemResolver::DoUpgrade - Attempt to upgrade this package         /*{{{*/
 532 // ---------------------------------------------------------------------
 533 /* This goes through and tries to reinstall packages to make this package
 534    installable */
 535 bool pkgProblemResolver::DoUpgrade(pkgCache::PkgIterator Pkg)
 536 {
 537    pkgDepCache::ActionGroup group(Cache);
 538
 539    if ((Flags[Pkg->ID] & Upgradable) == 0 || Cache[Pkg].Upgradable() == false)
 540       return false;
 541    if ((Flags[Pkg->ID] & Protected) == Protected)
 542       return false;
 543
 544    Flags[Pkg->ID] &= ~Upgradable;
 545
 546    bool WasKept = Cache[Pkg].Keep();
 547    Cache.MarkInstall(Pkg, false, 0, false);
 548
 549    // This must be a virtual package or something like that.
 550    if (Cache[Pkg].InstVerIter(Cache).end() == true)
 551       return false;
 552
 553    // Isolate the problem dependency
 554    bool Fail = false;
 555    for (pkgCache::DepIterator D = Cache[Pkg].InstVerIter(Cache).DependsList(); D.end() == false;)
 556    {
 557       // Compute a single dependency element (glob or)
 558       pkgCache::DepIterator Start = D;
 559       pkgCache::DepIterator End = D;
 560       for (bool LastOR = true; D.end() == false && LastOR == true;)
 561       {
 562          LastOR = (D->CompareOp & pkgCache::Dep::Or) == pkgCache::Dep::Or;
 563          ++D;
 564          if (LastOR == true)
 565             End = D;
 566       }
 567
 568       // We only worry about critical deps.
 569       if (End.IsCritical() != true)
 570          continue;
 571
 572       // Iterate over all the members in the or group
 573       while (1)
 574       {
 575          // Dep is ok now
 576          if ((Cache[End] & pkgDepCache::DepGInstall) == pkgDepCache::DepGInstall)
 577             break;
 578
 579          // Do not change protected packages
 580          PkgIterator P = Start.SmartTargetPkg();
 581          if ((Flags[P->ID] & Protected) == Protected)
 582          {
 583             if (Debug == true)
 584                clog << "    Reinst Failed because of protected " << P.FullName(false) << endl;
 585             Fail = true;
 586          }
 587          else
 588          {
 589             // Upgrade the package if the candidate version will fix the problem.
 590             if ((Cache[Start] & pkgDepCache::DepCVer) == pkgDepCache::DepCVer)
 591             {
 592                if (DoUpgrade(P) == false)
 593                {
 594                   if (Debug == true)
 595                      clog << "    Reinst Failed because of " << P.FullName(false) << endl;
 596                   Fail = true;
 597                }
 598                else
 599                {
 600                   Fail = false;
 601                   break;
 602                }
 603             }
 604             else
 605             {
 606                /* We let the algorithm deal with conflicts on its next iteration,
 607                 it is much smarter than us */
 608                if (Start.IsNegative() == true)
 609                    break;
 610
 611                if (Debug == true)
 612                   clog << "    Reinst Failed early because of " << Start.TargetPkg().FullName(false) << endl;
 613                Fail = true;
 614             }
 615          }
 616
 617          if (Start == End)
 618             break;
 619          ++Start;
 620       }
 621       if (Fail == true)
 622          break;
 623    }
 624
 625    // Undo our operations - it might be smart to undo everything this did..
 626    if (Fail == true)
 627    {
 628       if (WasKept == true)
 629          Cache.MarkKeep(Pkg, false, false);
 630       else
 631          Cache.MarkDelete(Pkg, false, 0, false);
 632       return false;
 633    }
 634
 635    if (Debug == true)
 636       clog << "  Re-Instated " << Pkg.FullName(false) << endl;
 637    return true;
 638 }
 639                                                                         /*}}}*/
 640 // ProblemResolver::Resolve - calls a resolver to fix the situation     /*{{{*/
 641 bool pkgProblemResolver::Resolve(bool BrokenFix, OpProgress * const Progress)
 642 {
 643    std::string const solver = _config->Find("APT::Solver", "internal");
 644    if (solver != "internal")
 645       return EDSP::ResolveExternal(solver.c_str(), Cache, false, false, false, Progress);
 646    return ResolveInternal(BrokenFix);
 647 }
 648                                                                         /*}}}*/
 649 // ProblemResolver::ResolveInternal - Run the resolution pass           /*{{{*/
 650 // ---------------------------------------------------------------------
 651 /* This routines works by calculating a score for each package. The score
 652    is derived by considering the package's priority and all reverse
 653    dependents giving an integer that reflects the amount of breakage that
 654    adjusting the package will inflict.
 655
 656    It goes from highest score to lowest and corrects all of the breaks by
 657    keeping or removing the dependent packages. If that fails then it removes
 658    the package itself and goes on. The routine should be able to intelligently
 659    go from any broken state to a fixed state.
 660
 661    The BrokenFix flag enables a mode where the algorithm tries to
 662    upgrade packages to advoid problems. */
 663 bool pkgProblemResolver::ResolveInternal(bool const BrokenFix)
 664 {
 665    pkgDepCache::ActionGroup group(Cache);
 666
 667    // Record which packages are marked for install
 668    bool Again = false;
 669    do
 670    {
 671       Again = false;
 672       for (pkgCache::PkgIterator I = Cache.PkgBegin(); I.end() == false; ++I)
 673       {
 674          if (Cache[I].Install() == true)
 675             Flags[I->ID] |= PreInstalled;
 676          else
 677          {
 678             if (Cache[I].InstBroken() == true && BrokenFix == true)
 679             {
 680                Cache.MarkInstall(I, false, 0, false);
 681                if (Cache[I].Install() == true)
 682                   Again = true;
 683             }
 684
 685             Flags[I->ID] &= ~PreInstalled;
 686          }
 687          Flags[I->ID] |= Upgradable;
 688       }
 689    }
 690    while (Again == true);
 691
 692    if (Debug == true) {
 693       clog << "Starting pkgProblemResolver with broken count: "
 694            << Cache.BrokenCount() << endl;
 695    }
 696
 697    MakeScores();
 698
 699    unsigned long const Size = Cache.Head().PackageCount;
 700
 701    /* We have to order the packages so that the broken fixing pass
 702       operates from highest score to lowest. This prevents problems when
 703       high score packages cause the removal of lower score packages that
 704       would cause the removal of even lower score packages. */
 705    std::unique_ptr<pkgCache::Package *[]> PList(new pkgCache::Package *[Size]);
 706    pkgCache::Package **PEnd = PList.get();
 707    for (pkgCache::PkgIterator I = Cache.PkgBegin(); I.end() == false; ++I)
 708       *PEnd++ = I;
 709    This = this;
 710    qsort(PList.get(),PEnd - PList.get(),sizeof(PList[0]),&ScoreSort);
 711
 712    if (_config->FindB("Debug::pkgProblemResolver::ShowScores",false) == true)
 713    {
 714       clog << "Show Scores" << endl;
 715       for (pkgCache::Package **K = PList.get(); K != PEnd; K++)
 716          if (Scores[(*K)->ID] != 0)
 717          {
 718            pkgCache::PkgIterator Pkg(Cache,*K);
 719            clog << Scores[(*K)->ID] << ' ' << Pkg << std::endl;
 720          }
 721    }
 722
 723    if (Debug == true) {
 724       clog << "Starting 2 pkgProblemResolver with broken count: "
 725            << Cache.BrokenCount() << endl;
 726    }
 727
 728    /* Now consider all broken packages. For each broken package we either
 729       remove the package or fix it's problem. We do this once, it should
 730       not be possible for a loop to form (that is a < b < c and fixing b by
 731       changing a breaks c) */
 732    bool Change = true;
 733    bool const TryFixByInstall = _config->FindB("pkgProblemResolver::FixByInstall", true);
 734    for (int Counter = 0; Counter != 10 && Change == true; Counter++)
 735    {
 736       Change = false;
 737       for (pkgCache::Package **K = PList.get(); K != PEnd; K++)
 738       {
 739          pkgCache::PkgIterator I(Cache,*K);
 740
 741          /* We attempt to install this and see if any breaks result,
 742             this takes care of some strange cases */
 743          if (Cache[I].CandidateVer != Cache[I].InstallVer &&
 744              I->CurrentVer != 0 && Cache[I].InstallVer != 0 &&
 745              (Flags[I->ID] & PreInstalled) != 0 &&
 746              (Flags[I->ID] & Protected) == 0 &&
 747              (Flags[I->ID] & ReInstateTried) == 0)
 748          {
 749             if (Debug == true)
 750                clog << " Try to Re-Instate (" << Counter << ") " << I.FullName(false) << endl;
 751             unsigned long OldBreaks = Cache.BrokenCount();
 752             pkgCache::Version *OldVer = Cache[I].InstallVer;
 753             Flags[I->ID] &= ReInstateTried;
 754
 755             Cache.MarkInstall(I, false, 0, false);
 756             if (Cache[I].InstBroken() == true ||
 757                 OldBreaks < Cache.BrokenCount())
 758             {
 759                if (OldVer == 0)
 760                   Cache.MarkDelete(I, false, 0, false);
 761                else
 762                   Cache.MarkKeep(I, false, false);
 763             }
 764             else
 765                if (Debug == true)
 766                   clog << "Re-Instated " << I.FullName(false) << " (" << OldBreaks << " vs " << Cache.BrokenCount() << ')' << endl;
 767          }
 768
 769          if (Cache[I].InstallVer == 0 || Cache[I].InstBroken() == false)
 770             continue;
 771
 772          if (Debug == true)
 773             clog << "Investigating (" << Counter << ") " << I << endl;
 774
 775          // Isolate the problem dependency
 776          PackageKill KillList[100];
 777          PackageKill *LEnd = KillList;
 778          bool InOr = false;
 779          pkgCache::DepIterator Start;
 780          pkgCache::DepIterator End;
 781          PackageKill *OldEnd = LEnd;
 782
 783          enum {OrRemove,OrKeep} OrOp = OrRemove;
 784          for (pkgCache::DepIterator D = Cache[I].InstVerIter(Cache).DependsList();
 785               D.end() == false || InOr == true;)
 786          {
 787             // Compute a single dependency element (glob or)
 788             if (Start == End)
 789             {
 790                // Decide what to do
 791                if (InOr == true && OldEnd == LEnd)
 792                {
 793                   if (OrOp == OrRemove)
 794                   {
 795                      if ((Flags[I->ID] & Protected) != Protected)
 796                      {
 797                         if (Debug == true)
 798                            clog << "  Or group remove for " << I.FullName(false) << endl;
 799                         Cache.MarkDelete(I, false, 0, false);
 800                         Change = true;
 801                      }
 802                   }
 803                   else if (OrOp == OrKeep)
 804                   {
 805                      if (Debug == true)
 806                         clog << "  Or group keep for " << I.FullName(false) << endl;
 807                      Cache.MarkKeep(I, false, false);
 808                      Change = true;
 809                   }
 810                }
 811
 812                /* We do an extra loop (as above) to finalize the or group
 813                   processing */
 814                InOr = false;
 815                OrOp = OrRemove;
 816                D.GlobOr(Start,End);
 817                if (Start.end() == true)
 818                   break;
 819
 820                // We only worry about critical deps.
 821                if (End.IsCritical() != true)
 822                   continue;
 823
 824                InOr = Start != End;
 825                OldEnd = LEnd;
 826             }
 827             else
 828             {
 829                ++Start;
 830                // We only worry about critical deps.
 831                if (Start.IsCritical() != true)
 832                   continue;
 833             }
 834
 835             // Dep is ok
 836             if ((Cache[End] & pkgDepCache::DepGInstall) == pkgDepCache::DepGInstall)
 837             {
 838                InOr = false;
 839                continue;
 840             }
 841
 842             if (Debug == true)
 843                clog << "Broken " << Start << endl;
 844
 845             /* Look across the version list. If there are no possible
 846                targets then we keep the package and bail. This is necessary
 847                if a package has a dep on another package that can't be found */
 848             std::unique_ptr<pkgCache::Version *[]> VList(Start.AllTargets());
 849             if (VList[0] == 0 && (Flags[I->ID] & Protected) != Protected &&
 850                 Start.IsNegative() == false &&
 851                 Cache[I].NowBroken() == false)
 852             {
 853                if (InOr == true)
 854                {
 855                   /* No keep choice because the keep being OK could be the
 856                      result of another element in the OR group! */
 857                   continue;
 858                }
 859
 860                Change = true;
 861                Cache.MarkKeep(I, false, false);
 862                break;
 863             }
 864
 865             bool Done = false;
 866             for (pkgCache::Version **V = VList.get(); *V != 0; V++)
 867             {
 868                pkgCache::VerIterator Ver(Cache,*V);
 869                pkgCache::PkgIterator Pkg = Ver.ParentPkg();
 870
 871                /* This is a conflicts, and the version we are looking
 872                   at is not the currently selected version of the
 873                   package, which means it is not necessary to
 874                   remove/keep */
 875                if (Cache[Pkg].InstallVer != Ver && Start.IsNegative() == true)
 876                {
 877                   if (Debug)
 878                      clog << "  Conflicts//Breaks against version "
 879                           << Ver.VerStr() << " for " << Pkg.Name()
 880                           << " but that is not InstVer, ignoring"
 881                           << endl;
 882                   continue;
 883                }
 884
 885                if (Debug == true)
 886                   clog << "  Considering " << Pkg.FullName(false) << ' ' << Scores[Pkg->ID] <<
 887                   " as a solution to " << I.FullName(false) << ' ' << Scores[I->ID] << endl;
 888
 889                /* Try to fix the package under consideration rather than
 890                   fiddle with the VList package */
 891                if (Scores[I->ID] <= Scores[Pkg->ID] ||
 892                    ((Cache[Start] & pkgDepCache::DepNow) == 0 &&
 893                     End.IsNegative() == false))
 894                {
 895                   // Try a little harder to fix protected packages..
 896                   if ((Flags[I->ID] & Protected) == Protected)
 897                   {
 898                      if (DoUpgrade(Pkg) == true)
 899                      {
 900                         if (Scores[Pkg->ID] > Scores[I->ID])
 901                            Scores[Pkg->ID] = Scores[I->ID];
 902                         break;
 903                      }
 904
 905                      continue;
 906                   }
 907
 908                   /* See if a keep will do, unless the package is protected,
 909                      then installing it will be necessary */
 910                   bool Installed = Cache[I].Install();
 911                   Cache.MarkKeep(I, false, false);
 912                   if (Cache[I].InstBroken() == false)
 913                   {
 914                      // Unwind operation will be keep now
 915                      if (OrOp == OrRemove)
 916                         OrOp = OrKeep;
 917
 918                      // Restore
 919                      if (InOr == true && Installed == true)
 920                         Cache.MarkInstall(I, false, 0, false);
 921
 922                      if (Debug == true)
 923                         clog << "  Holding Back " << I.FullName(false) << " rather than change " << Start.TargetPkg().FullName(false) << endl;
 924                   }
 925                   else
 926                   {
 927                      if (BrokenFix == false || DoUpgrade(I) == false)
 928                      {
 929                         // Consider other options
 930                         if (InOr == false || Cache[I].Garbage == true)
 931                         {
 932                            if (Debug == true)
 933                               clog << "  Removing " << I.FullName(false) << " rather than change " << Start.TargetPkg().FullName(false) << endl;
 934                            Cache.MarkDelete(I, false, 0, false);
 935                            if (Counter > 1 && Scores[Pkg->ID] > Scores[I->ID])
 936                               Scores[I->ID] = Scores[Pkg->ID];
 937                         }
 938                         else if (TryFixByInstall == true &&
 939                                  Start.TargetPkg()->CurrentVer == 0 &&
 940                                  Cache[Start.TargetPkg()].Delete() == false &&
 941                                  (Flags[Start.TargetPkg()->ID] & ToRemove) != ToRemove &&
 942                                  Cache.GetCandidateVer(Start.TargetPkg()).end() == false)
 943                         {
 944                            /* Before removing or keeping the package with the broken dependency
 945                               try instead to install the first not previously installed package
 946                               solving this dependency. This helps every time a previous solver
 947                               is removed by the resolver because of a conflict or alike but it is
 948                               dangerous as it could trigger new breaks/conflicts… */
 949                            if (Debug == true)
 950                               clog << "  Try Installing " << Start.TargetPkg() << " before changing " << I.FullName(false) << std::endl;
 951                            unsigned long const OldBroken = Cache.BrokenCount();
 952                            Cache.MarkInstall(Start.TargetPkg(), true, 1, false);
 953                            // FIXME: we should undo the complete MarkInstall process here
 954                            if (Cache[Start.TargetPkg()].InstBroken() == true || Cache.BrokenCount() > OldBroken)
 955                               Cache.MarkDelete(Start.TargetPkg(), false, 1, false);
 956                         }
 957                      }
 958                   }
 959
 960                   Change = true;
 961                   Done = true;
 962                   break;
 963                }
 964                else
 965                {
 966                   if (Start->Type == pkgCache::Dep::DpkgBreaks)
 967                   {
 968                      // first, try upgradring the package, if that
 969                      // does not help, the breaks goes onto the
 970                      // kill list
 971                      //
 972                      // FIXME: use DoUpgrade(Pkg) instead?
 973                      if (Cache[End] & pkgDepCache::DepGCVer)
 974                      {
 975                         if (Debug)
 976                            clog << "  Upgrading " << Pkg.FullName(false) << " due to Breaks field in " << I.FullName(false) << endl;
 977                         Cache.MarkInstall(Pkg, false, 0, false);
 978                         continue;
 979                      }
 980                   }
 981
 982                   // Skip adding to the kill list if it is protected
 983                   if ((Flags[Pkg->ID] & Protected) != 0)
 984                      continue;
 985
 986                   if (Debug == true)
 987                      clog << "  Added " << Pkg.FullName(false) << " to the remove list" << endl;
 988
 989                   LEnd->Pkg = Pkg;
 990                   LEnd->Dep = End;
 991                   LEnd++;
 992
 993                   if (Start.IsNegative() == false)
 994                      break;
 995                }
 996             }
 997
 998             // Hm, nothing can possibly satisify this dep. Nuke it.
 999             if (VList[0] == 0 &&
1000                 Start.IsNegative() == false &&
1001                 (Flags[I->ID] & Protected) != Protected)
1002             {
1003                bool Installed = Cache[I].Install();
1004                Cache.MarkKeep(I);
1005                if (Cache[I].InstBroken() == false)
1006                {
1007                   // Unwind operation will be keep now
1008                   if (OrOp == OrRemove)
1009                      OrOp = OrKeep;
1010
1011                   // Restore
1012                   if (InOr == true && Installed == true)
1013                      Cache.MarkInstall(I, false, 0, false);
1014
1015                   if (Debug == true)
1016                      clog << "  Holding Back " << I.FullName(false) << " because I can't find " << Start.TargetPkg().FullName(false) << endl;
1017                }
1018                else
1019                {
1020                   if (Debug == true)
1021                      clog << "  Removing " << I.FullName(false) << " because I can't find " << Start.TargetPkg().FullName(false) << endl;
1022                   if (InOr == false)
1023                      Cache.MarkDelete(I, false, 0, false);
1024                }
1025
1026                Change = true;
1027                Done = true;
1028             }
1029
1030             // Try some more
1031             if (InOr == true)
1032                continue;
1033
1034             if (Done == true)
1035                break;
1036          }
1037
1038          // Apply the kill list now
1039          if (Cache[I].InstallVer != 0)
1040          {
1041             for (PackageKill *J = KillList; J != LEnd; J++)
1042             {
1043                Change = true;
1044                if ((Cache[J->Dep] & pkgDepCache::DepGNow) == 0)
1045                {
1046                   if (J->Dep.IsNegative() == true)
1047                   {
1048                      if (Debug == true)
1049                         clog << "  Fixing " << I.FullName(false) << " via remove of " << J->Pkg.FullName(false) << endl;
1050                      Cache.MarkDelete(J->Pkg, false, 0, false);
1051                   }
1052                }
1053                else
1054                {
1055                   if (Debug == true)
1056                      clog << "  Fixing " << I.FullName(false) << " via keep of " << J->Pkg.FullName(false) << endl;
1057                   Cache.MarkKeep(J->Pkg, false, false);
1058                }
1059
1060                if (Counter > 1)
1061                {
1062                   if (Scores[I->ID] > Scores[J->Pkg->ID])
1063                      Scores[J->Pkg->ID] = Scores[I->ID];
1064                }
1065             }
1066          }
1067       }
1068    }
1069
1070    if (Debug == true)
1071       clog << "Done" << endl;
1072
1073    if (Cache.BrokenCount() != 0)
1074    {
1075       // See if this is the result of a hold
1076       pkgCache::PkgIterator I = Cache.PkgBegin();
1077       for (;I.end() != true; ++I)
1078       {
1079          if (Cache[I].InstBroken() == false)
1080             continue;
1081          if ((Flags[I->ID] & Protected) != Protected)
1082             return _error->Error(_("Error, pkgProblemResolver::Resolve generated breaks, this may be caused by held packages."));
1083       }
1084       return _error->Error(_("Unable to correct problems, you have held broken packages."));
1085    }
1086
1087    // set the auto-flags (mvo: I'm not sure if we _really_ need this)
1088    pkgCache::PkgIterator I = Cache.PkgBegin();
1089    for (;I.end() != true; ++I) {
1090       if (Cache[I].NewInstall() && !(Flags[I->ID] & PreInstalled)) {
1091          if(_config->FindI("Debug::pkgAutoRemove",false)) {
1092             std::clog << "Resolve installed new pkg: " << I.FullName(false)
1093                       << " (now marking it as auto)" << std::endl;
1094          }
1095          Cache[I].Flags |= pkgCache::Flag::Auto;
1096       }
1097    }
1098
1099
1100    return true;
1101 }
1102                                                                         /*}}}*/
1103 // ProblemResolver::BreaksInstOrPolicy - Check if the given pkg is broken/*{{{*/
1104 // ---------------------------------------------------------------------
1105 /* This checks if the given package is broken either by a hard dependency
1106    (InstBroken()) or by introducing a new policy breakage e.g. new
1107    unsatisfied recommends for a package that was in "policy-good" state
1108
1109    Note that this is not perfect as it will ignore further breakage
1110    for already broken policy (recommends)
1111 */
1112 bool pkgProblemResolver::InstOrNewPolicyBroken(pkgCache::PkgIterator I)
1113 {
1114    // a broken install is always a problem
1115    if (Cache[I].InstBroken() == true)
1116    {
1117       if (Debug == true)
1118          std::clog << "  Dependencies are not satisfied for " << I << std::endl;
1119       return true;
1120    }
1121
1122    // a newly broken policy (recommends/suggests) is a problem
1123    if (Cache[I].NowPolicyBroken() == false &&
1124        Cache[I].InstPolicyBroken() == true)
1125    {
1126       if (Debug == true)
1127          std::clog << "  Policy breaks with upgrade of " << I << std::endl;
1128       return true;
1129    }
1130
1131    return false;
1132 }
1133                                                                         /*}}}*/
1134 // ProblemResolver::ResolveByKeep - Resolve problems using keep         /*{{{*/
1135 // ---------------------------------------------------------------------
1136 /* This is the work horse of the soft upgrade routine. It is very gental
1137    in that it does not install or remove any packages. It is assumed that the
1138    system was non-broken previously. */
1139 bool pkgProblemResolver::ResolveByKeep(OpProgress * const Progress)
1140 {
1141    std::string const solver = _config->Find("APT::Solver", "internal");
1142    if (solver != "internal")
1143       return EDSP::ResolveExternal(solver.c_str(), Cache, true, false, false, Progress);
1144    return ResolveByKeepInternal();
1145 }
1146                                                                         /*}}}*/
1147 // ProblemResolver::ResolveByKeepInternal - Resolve problems using keep /*{{{*/
1148 // ---------------------------------------------------------------------
1149 /* This is the work horse of the soft upgrade routine. It is very gental
1150    in that it does not install or remove any packages. It is assumed that the
1151    system was non-broken previously. */
1152 bool pkgProblemResolver::ResolveByKeepInternal()
1153 {
1154    pkgDepCache::ActionGroup group(Cache);
1155
1156    unsigned long Size = Cache.Head().PackageCount;
1157
1158    MakeScores();
1159
1160    /* We have to order the packages so that the broken fixing pass
1161       operates from highest score to lowest. This prevents problems when
1162       high score packages cause the removal of lower score packages that
1163       would cause the removal of even lower score packages. */
1164    pkgCache::Package **PList = new pkgCache::Package *[Size];
1165    pkgCache::Package **PEnd = PList;
1166    for (pkgCache::PkgIterator I = Cache.PkgBegin(); I.end() == false; ++I)
1167       *PEnd++ = I;
1168    This = this;
1169    qsort(PList,PEnd - PList,sizeof(*PList),&ScoreSort);
1170
1171    if (_config->FindB("Debug::pkgProblemResolver::ShowScores",false) == true)
1172    {
1173       clog << "Show Scores" << endl;
1174       for (pkgCache::Package **K = PList; K != PEnd; K++)
1175          if (Scores[(*K)->ID] != 0)
1176          {
1177            pkgCache::PkgIterator Pkg(Cache,*K);
1178            clog << Scores[(*K)->ID] << ' ' << Pkg << std::endl;
1179          }
1180    }
1181
1182    if (Debug == true)
1183       clog << "Entering ResolveByKeep" << endl;
1184
1185    // Consider each broken package
1186    pkgCache::Package **LastStop = 0;
1187    for (pkgCache::Package **K = PList; K != PEnd; K++)
1188    {
1189       pkgCache::PkgIterator I(Cache,*K);
1190
1191       if (Cache[I].InstallVer == 0)
1192          continue;
1193
1194       if (InstOrNewPolicyBroken(I) == false)
1195          continue;
1196
1197       /* Keep the package. If this works then great, otherwise we have
1198          to be significantly more aggressive and manipulate its dependencies */
1199       if ((Flags[I->ID] & Protected) == 0)
1200       {
1201          if (Debug == true)
1202             clog << "Keeping package " << I.FullName(false) << endl;
1203          Cache.MarkKeep(I, false, false);
1204          if (InstOrNewPolicyBroken(I) == false)
1205          {
1206             K = PList - 1;
1207             continue;
1208          }
1209       }
1210
1211       // Isolate the problem dependencies
1212       for (pkgCache::DepIterator D = Cache[I].InstVerIter(Cache).DependsList(); D.end() == false;)
1213       {
1214          DepIterator Start;
1215          DepIterator End;
1216          D.GlobOr(Start,End);
1217
1218          // We only worry about critical deps.
1219          if (End.IsCritical() != true)
1220             continue;
1221
1222          // Dep is ok
1223          if ((Cache[End] & pkgDepCache::DepGInstall) == pkgDepCache::DepGInstall)
1224             continue;
1225
1226          /* Hm, the group is broken.. I suppose the best thing to do is to
1227             is to try every combination of keep/not-keep for the set, but thats
1228             slow, and this never happens, just be conservative and assume the
1229             list of ors is in preference and keep till it starts to work. */
1230          while (true)
1231          {
1232             if (Debug == true)
1233                clog << "Package " << I.FullName(false) << " " << Start << endl;
1234
1235             // Look at all the possible provides on this package
1236             std::unique_ptr<pkgCache::Version *[]> VList(Start.AllTargets());
1237             for (pkgCache::Version **V = VList.get(); *V != 0; V++)
1238             {
1239                pkgCache::VerIterator Ver(Cache,*V);
1240                pkgCache::PkgIterator Pkg = Ver.ParentPkg();
1241
1242                // It is not keepable
1243                if (Cache[Pkg].InstallVer == 0 ||
1244                    Pkg->CurrentVer == 0)
1245                   continue;
1246
1247                if ((Flags[I->ID] & Protected) == 0)
1248                {
1249                   if (Debug == true)
1250                      clog << "  Keeping Package " << Pkg.FullName(false) << " due to " << Start.DepType() << endl;
1251                   Cache.MarkKeep(Pkg, false, false);
1252                }
1253
1254                if (InstOrNewPolicyBroken(I) == false)
1255                   break;
1256             }
1257
1258             if (InstOrNewPolicyBroken(I) == false)
1259                break;
1260
1261             if (Start == End)
1262                break;
1263             ++Start;
1264          }
1265
1266          if (InstOrNewPolicyBroken(I) == false)
1267             break;
1268       }
1269
1270       if (InstOrNewPolicyBroken(I) == true)
1271          continue;
1272
1273       // Restart again.
1274       if (K == LastStop) {
1275           // I is an iterator based off our temporary package list,
1276           // so copy the name we need before deleting the temporary list
1277           std::string const LoopingPackage = I.FullName(false);
1278           delete[] PList;
1279           return _error->Error("Internal Error, pkgProblemResolver::ResolveByKeep is looping on package %s.", LoopingPackage.c_str());
1280       }
1281       LastStop = K;
1282       K = PList - 1;
1283    }
1284
1285    delete[] PList;
1286    return true;
1287 }
1288                                                                         /*}}}*/
1289 // ProblemResolver::InstallProtect - deprecated cpu-eating no-op        /*{{{*/
1290 // ---------------------------------------------------------------------
1291 /* Actions issued with FromUser bit set are protected from further
1292    modification (expect by other calls with FromUser set) nowadays , so we
1293    don't need to reissue actions here, they are already set in stone. */
1294 void pkgProblemResolver::InstallProtect()
1295 {
1296    pkgDepCache::ActionGroup group(Cache);
1297
1298    for (pkgCache::PkgIterator I = Cache.PkgBegin(); I.end() == false; ++I)
1299    {
1300       if ((Flags[I->ID] & Protected) == Protected)
1301       {
1302          if ((Flags[I->ID] & ToRemove) == ToRemove)
1303             Cache.MarkDelete(I);
1304          else
1305          {
1306             // preserve the information whether the package was auto
1307             // or manually installed
1308             bool autoInst = (Cache[I].Flags & pkgCache::Flag::Auto);
1309             Cache.MarkInstall(I, false, 0, !autoInst);
1310          }
1311       }
1312    }
1313 }
1314                                                                         /*}}}*/
1315 // PrioSortList - Sort a list of versions by priority                   /*{{{*/
1316 // ---------------------------------------------------------------------
1317 /* This is ment to be used in conjunction with AllTargets to get a list
1318    of versions ordered by preference. */
1319 static pkgCache *PrioCache;
1320 static int PrioComp(const void *A,const void *B)
1321 {
1322    pkgCache::VerIterator L(*PrioCache,*(pkgCache::Version **)A);
1323    pkgCache::VerIterator R(*PrioCache,*(pkgCache::Version **)B);
1324
1325    if ((L.ParentPkg()->Flags & pkgCache::Flag::Essential) == pkgCache::Flag::Essential &&
1326        (R.ParentPkg()->Flags & pkgCache::Flag::Essential) != pkgCache::Flag::Essential)
1327      return 1;
1328    if ((L.ParentPkg()->Flags & pkgCache::Flag::Essential) != pkgCache::Flag::Essential &&
1329        (R.ParentPkg()->Flags & pkgCache::Flag::Essential) == pkgCache::Flag::Essential)
1330      return -1;
1331
1332    if ((L.ParentPkg()->Flags & pkgCache::Flag::Important) == pkgCache::Flag::Important &&
1333        (R.ParentPkg()->Flags & pkgCache::Flag::Important) != pkgCache::Flag::Important)
1334      return 1;
1335    if ((L.ParentPkg()->Flags & pkgCache::Flag::Important) != pkgCache::Flag::Important &&
1336        (R.ParentPkg()->Flags & pkgCache::Flag::Important) == pkgCache::Flag::Important)
1337      return -1;
1338
1339    if (L->Priority != R->Priority)
1340       return R->Priority - L->Priority;
1341    return strcmp(L.ParentPkg().Name(),R.ParentPkg().Name());
1342 }
1343 void pkgPrioSortList(pkgCache &Cache,pkgCache::Version **List)
1344 {
1345    unsigned long Count = 0;
1346    PrioCache = &Cache;
1347    for (pkgCache::Version **I = List; *I != 0; I++)
1348       Count++;
1349    qsort(List,Count,sizeof(*List),PrioComp);
1350 }
1351                                                                         /*}}}*/