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 <apt-pkg/algorithms.h>
  18 #include <apt-pkg/error.h>
  19 #include <apt-pkg/configuration.h>
  20 #include <apt-pkg/version.h>
  21 #include <apt-pkg/sptr.h>
  22 #include <apt-pkg/acquire-item.h>
  23
  24 #include <apti18n.h>
  25 #include <sys/types.h>
  26 #include <cstdlib>
  27 #include <algorithm>
  28 #include <iostream>
  29                                                                         /*}}}*/
  30 using namespace std;
  31
  32 pkgProblemResolver *pkgProblemResolver::This = 0;
  33
  34 // Simulate::Simulate - Constructor                                     /*{{{*/
  35 // ---------------------------------------------------------------------
  36 /* The legacy translations here of input Pkg iterators is obsolete,
  37    this is not necessary since the pkgCaches are fully shared now. */
  38 pkgSimulate::pkgSimulate(pkgDepCache *Cache) : pkgPackageManager(Cache),
  39                             iPolicy(Cache),
  40                             Sim(&Cache->GetCache(),&iPolicy),
  41                             group(Sim)
  42 {
  43    Sim.Init(0);
  44    Flags = new unsigned char[Cache->Head().PackageCount];
  45    memset(Flags,0,sizeof(*Flags)*Cache->Head().PackageCount);
  46
  47    // Fake a filename so as not to activate the media swapping
  48    string Jnk = "SIMULATE";
  49    for (unsigned int I = 0; I != Cache->Head().PackageCount; I++)
  50       FileNames[I] = Jnk;
  51 }
  52                                                                         /*}}}*/
  53 // Simulate::Describe - Describe a package                              /*{{{*/
  54 // ---------------------------------------------------------------------
  55 /* Parameter Current == true displays the current package version,
  56    Parameter Candidate == true displays the candidate package version */
  57 void pkgSimulate::Describe(PkgIterator Pkg,ostream &out,bool Current,bool Candidate)
  58 {
  59    VerIterator Ver(Sim);
  60
  61    out << Pkg.Name();
  62
  63    if (Current == true)
  64    {
  65       Ver = Pkg.CurrentVer();
  66       if (Ver.end() == false)
  67          out << " [" << Ver.VerStr() << ']';
  68    }
  69
  70    if (Candidate == true)
  71    {
  72       Ver = Sim[Pkg].CandidateVerIter(Sim);
  73       if (Ver.end() == true)
  74          return;
  75
  76       out << " (" << Ver.VerStr() << ' ' << Ver.RelStr() << ')';
  77    }
  78 }
  79                                                                         /*}}}*/
  80 // Simulate::Install - Simulate unpacking of a package                  /*{{{*/
  81 // ---------------------------------------------------------------------
  82 /* */
  83 bool pkgSimulate::Install(PkgIterator iPkg,string /*File*/)
  84 {
  85    // Adapt the iterator
  86    PkgIterator Pkg = Sim.FindPkg(iPkg.Name(), iPkg.Arch());
  87    Flags[Pkg->ID] = 1;
  88
  89    cout << "Inst ";
  90    Describe(Pkg,cout,true,true);
  91    Sim.MarkInstall(Pkg,false);
  92
  93    if (strcmp(Pkg.Arch(),"all") == 0)
  94    {
  95       pkgCache::GrpIterator G = Pkg.Group();
  96       pkgCache::GrpIterator iG = iPkg.Group();
  97       for (pkgCache::PkgIterator P = G.FindPkg("any"); P.end() != true; P = G.NextPkg(P))
  98       {
  99          if (strcmp(P.Arch(), "all") == 0)
 100             continue;
 101          if (iG.FindPkg(P.Arch())->CurrentVer == 0)
 102             continue;
 103          Flags[P->ID] = 1;
 104          Sim.MarkInstall(P, false);
 105       }
 106    }
 107
 108    // Look for broken conflicts+predepends.
 109    for (PkgIterator I = Sim.PkgBegin(); I.end() == false; I++)
 110    {
 111       if (Sim[I].InstallVer == 0)
 112          continue;
 113
 114       for (DepIterator D = Sim[I].InstVerIter(Sim).DependsList(); D.end() == false;)
 115       {
 116          DepIterator Start;
 117          DepIterator End;
 118          D.GlobOr(Start,End);
 119          if (Start->Type == pkgCache::Dep::Conflicts ||
 120              Start->Type == pkgCache::Dep::DpkgBreaks ||
 121              Start->Type == pkgCache::Dep::Obsoletes ||
 122              End->Type == pkgCache::Dep::PreDepends)
 123          {
 124             if ((Sim[End] & pkgDepCache::DepGInstall) == 0)
 125             {
 126                cout << " [" << I.Name() << " on " << Start.TargetPkg().Name() << ']';
 127                if (Start->Type == pkgCache::Dep::Conflicts)
 128                   _error->Error("Fatal, conflicts violated %s",I.Name());
 129             }
 130          }
 131       }
 132    }
 133
 134    if (Sim.BrokenCount() != 0)
 135       ShortBreaks();
 136    else
 137       cout << endl;
 138    return true;
 139 }
 140                                                                         /*}}}*/
 141 // Simulate::Configure - Simulate configuration of a Package            /*{{{*/
 142 // ---------------------------------------------------------------------
 143 /* This is not an acurate simulation of relatity, we should really not
 144    install the package.. For some investigations it may be necessary
 145    however. */
 146 bool pkgSimulate::Configure(PkgIterator iPkg)
 147 {
 148    // Adapt the iterator
 149    PkgIterator Pkg = Sim.FindPkg(iPkg.Name(), iPkg.Arch());
 150
 151    Flags[Pkg->ID] = 2;
 152
 153    if (strcmp(Pkg.Arch(),"all") == 0)
 154    {
 155       pkgCache::GrpIterator G = Pkg.Group();
 156       for (pkgCache::PkgIterator P = G.FindPkg("any"); P.end() != true; P = G.NextPkg(P))
 157       {
 158          if (strcmp(P.Arch(), "all") == 0)
 159             continue;
 160          if (Flags[P->ID] == 1)
 161             Flags[P->ID] = 2;
 162       }
 163    }
 164
 165 //   Sim.MarkInstall(Pkg,false);
 166    if (Sim[Pkg].InstBroken() == true)
 167    {
 168       cout << "Conf " << Pkg.Name() << " broken" << endl;
 169
 170       Sim.Update();
 171
 172       // Print out each package and the failed dependencies
 173       for (pkgCache::DepIterator D = Sim[Pkg].InstVerIter(Sim).DependsList(); D.end() == false; D++)
 174       {
 175          if (Sim.IsImportantDep(D) == false ||
 176              (Sim[D] & pkgDepCache::DepInstall) != 0)
 177             continue;
 178
 179          if (D->Type == pkgCache::Dep::Obsoletes)
 180             cout << " Obsoletes:" << D.TargetPkg().Name();
 181          else if (D->Type == pkgCache::Dep::Conflicts)
 182             cout << " Conflicts:" << D.TargetPkg().Name();
 183          else if (D->Type == pkgCache::Dep::DpkgBreaks)
 184             cout << " Breaks:" << D.TargetPkg().Name();
 185          else
 186             cout << " Depends:" << D.TargetPkg().Name();
 187       }
 188       cout << endl;
 189
 190       _error->Error("Conf Broken %s",Pkg.Name());
 191    }
 192    else
 193    {
 194       cout << "Conf ";
 195       Describe(Pkg,cout,false,true);
 196    }
 197
 198    if (Sim.BrokenCount() != 0)
 199       ShortBreaks();
 200    else
 201       cout << endl;
 202
 203    return true;
 204 }
 205                                                                         /*}}}*/
 206 // Simulate::Remove - Simulate the removal of a package                 /*{{{*/
 207 // ---------------------------------------------------------------------
 208 /* */
 209 bool pkgSimulate::Remove(PkgIterator iPkg,bool Purge)
 210 {
 211    // Adapt the iterator
 212    PkgIterator Pkg = Sim.FindPkg(iPkg.Name(), iPkg.Arch());
 213
 214    Flags[Pkg->ID] = 3;
 215    Sim.MarkDelete(Pkg);
 216
 217    if (strcmp(Pkg.Arch(),"all") == 0)
 218    {
 219       pkgCache::GrpIterator G = Pkg.Group();
 220       pkgCache::GrpIterator iG = iPkg.Group();
 221       for (pkgCache::PkgIterator P = G.FindPkg("any"); P.end() != true; P = G.NextPkg(P))
 222       {
 223          if (strcmp(P.Arch(), "all") == 0)
 224             continue;
 225          if (iG.FindPkg(P.Arch())->CurrentVer == 0)
 226             continue;
 227          Flags[P->ID] = 3;
 228          Sim.MarkDelete(P);
 229       }
 230    }
 231
 232    if (Purge == true)
 233       cout << "Purg ";
 234    else
 235       cout << "Remv ";
 236    Describe(Pkg,cout,true,false);
 237
 238    if (Sim.BrokenCount() != 0)
 239       ShortBreaks();
 240    else
 241       cout << endl;
 242
 243    return true;
 244 }
 245                                                                         /*}}}*/
 246 // Simulate::ShortBreaks - Print out a short line describing all breaks /*{{{*/
 247 // ---------------------------------------------------------------------
 248 /* */
 249 void pkgSimulate::ShortBreaks()
 250 {
 251    cout << " [";
 252    for (PkgIterator I = Sim.PkgBegin(); I.end() == false; I++)
 253    {
 254       if (Sim[I].InstBroken() == true)
 255       {
 256          if (Flags[I->ID] == 0)
 257             cout << I.Name() << ' ';
 258 /*       else
 259             cout << I.Name() << "! ";*/
 260       }
 261    }
 262    cout << ']' << endl;
 263 }
 264                                                                         /*}}}*/
 265 // ApplyStatus - Adjust for non-ok packages                             /*{{{*/
 266 // ---------------------------------------------------------------------
 267 /* We attempt to change the state of the all packages that have failed
 268    installation toward their real state. The ordering code will perform
 269    the necessary calculations to deal with the problems. */
 270 bool pkgApplyStatus(pkgDepCache &Cache)
 271 {
 272    pkgDepCache::ActionGroup group(Cache);
 273
 274    for (pkgCache::PkgIterator I = Cache.PkgBegin(); I.end() == false; I++)
 275    {
 276       if (I->VersionList == 0)
 277          continue;
 278
 279       // Only choice for a ReInstReq package is to reinstall
 280       if (I->InstState == pkgCache::State::ReInstReq ||
 281           I->InstState == pkgCache::State::HoldReInstReq)
 282       {
 283          if (I->CurrentVer != 0 && I.CurrentVer().Downloadable() == true)
 284             Cache.MarkKeep(I, false, false);
 285          else
 286          {
 287             // Is this right? Will dpkg choke on an upgrade?
 288             if (Cache[I].CandidateVer != 0 &&
 289                  Cache[I].CandidateVerIter(Cache).Downloadable() == true)
 290                Cache.MarkInstall(I, false, 0, false);
 291             else
 292                return _error->Error(_("The package %s needs to be reinstalled, "
 293                                     "but I can't find an archive for it."),I.Name());
 294          }
 295
 296          continue;
 297       }
 298
 299       switch (I->CurrentState)
 300       {
 301          /* This means installation failed somehow - it does not need to be
 302             re-unpacked (probably) */
 303          case pkgCache::State::UnPacked:
 304          case pkgCache::State::HalfConfigured:
 305          case pkgCache::State::TriggersAwaited:
 306          case pkgCache::State::TriggersPending:
 307          if ((I->CurrentVer != 0 && I.CurrentVer().Downloadable() == true) ||
 308              I.State() != pkgCache::PkgIterator::NeedsUnpack)
 309             Cache.MarkKeep(I, false, false);
 310          else
 311          {
 312             if (Cache[I].CandidateVer != 0 &&
 313                  Cache[I].CandidateVerIter(Cache).Downloadable() == true)
 314                Cache.MarkInstall(I, true, 0, false);
 315             else
 316                Cache.MarkDelete(I);
 317          }
 318          break;
 319
 320          // This means removal failed
 321          case pkgCache::State::HalfInstalled:
 322          Cache.MarkDelete(I);
 323          break;
 324
 325          default:
 326          if (I->InstState != pkgCache::State::Ok)
 327             return _error->Error("The package %s is not ok and I "
 328                                  "don't know how to fix it!",I.Name());
 329       }
 330    }
 331    return true;
 332 }
 333                                                                         /*}}}*/
 334 // FixBroken - Fix broken packages                                      /*{{{*/
 335 // ---------------------------------------------------------------------
 336 /* This autoinstalls every broken package and then runs the problem resolver
 337    on the result. */
 338 bool pkgFixBroken(pkgDepCache &Cache)
 339 {
 340    pkgDepCache::ActionGroup group(Cache);
 341
 342    // Auto upgrade all broken packages
 343    for (pkgCache::PkgIterator I = Cache.PkgBegin(); I.end() == false; I++)
 344       if (Cache[I].NowBroken() == true)
 345          Cache.MarkInstall(I, true, 0, false);
 346
 347    /* Fix packages that are in a NeedArchive state but don't have a
 348       downloadable install version */
 349    for (pkgCache::PkgIterator I = Cache.PkgBegin(); I.end() == false; I++)
 350    {
 351       if (I.State() != pkgCache::PkgIterator::NeedsUnpack ||
 352           Cache[I].Delete() == true)
 353          continue;
 354
 355       if (Cache[I].InstVerIter(Cache).Downloadable() == false)
 356          continue;
 357
 358       Cache.MarkInstall(I, true, 0, false);
 359    }
 360
 361    pkgProblemResolver Fix(&Cache);
 362    return Fix.Resolve(true);
 363 }
 364                                                                         /*}}}*/
 365 // DistUpgrade - Distribution upgrade                                   /*{{{*/
 366 // ---------------------------------------------------------------------
 367 /* This autoinstalls every package and then force installs every
 368    pre-existing package. This creates the initial set of conditions which
 369    most likely contain problems because too many things were installed.
 370
 371    The problem resolver is used to resolve the problems.
 372  */
 373 bool pkgDistUpgrade(pkgDepCache &Cache)
 374 {
 375    pkgDepCache::ActionGroup group(Cache);
 376
 377    /* Auto upgrade all installed packages, this provides the basis
 378       for the installation */
 379    for (pkgCache::PkgIterator I = Cache.PkgBegin(); I.end() == false; I++)
 380       if (I->CurrentVer != 0)
 381          Cache.MarkInstall(I, true, 0, false);
 382
 383    /* Now, auto upgrade all essential packages - this ensures that
 384       the essential packages are present and working */
 385    for (pkgCache::PkgIterator I = Cache.PkgBegin(); I.end() == false; I++)
 386       if ((I->Flags & pkgCache::Flag::Essential) == pkgCache::Flag::Essential)
 387          Cache.MarkInstall(I, true, 0, false);
 388
 389    /* We do it again over all previously installed packages to force
 390       conflict resolution on them all. */
 391    for (pkgCache::PkgIterator I = Cache.PkgBegin(); I.end() == false; I++)
 392       if (I->CurrentVer != 0)
 393          Cache.MarkInstall(I, false, 0, false);
 394
 395    pkgProblemResolver Fix(&Cache);
 396
 397    // Hold back held packages.
 398    if (_config->FindB("APT::Ignore-Hold",false) == false)
 399    {
 400       for (pkgCache::PkgIterator I = Cache.PkgBegin(); I.end() == false; I++)
 401       {
 402          if (I->SelectedState == pkgCache::State::Hold)
 403          {
 404             Fix.Protect(I);
 405             Cache.MarkKeep(I, false, false);
 406          }
 407       }
 408    }
 409
 410    return Fix.Resolve();
 411 }
 412                                                                         /*}}}*/
 413 // AllUpgrade - Upgrade as many packages as possible                    /*{{{*/
 414 // ---------------------------------------------------------------------
 415 /* Right now the system must be consistent before this can be called.
 416    It also will not change packages marked for install, it only tries
 417    to install packages not marked for install */
 418 bool pkgAllUpgrade(pkgDepCache &Cache)
 419 {
 420    pkgDepCache::ActionGroup group(Cache);
 421
 422    pkgProblemResolver Fix(&Cache);
 423
 424    if (Cache.BrokenCount() != 0)
 425       return false;
 426
 427    // Upgrade all installed packages
 428    for (pkgCache::PkgIterator I = Cache.PkgBegin(); I.end() == false; I++)
 429    {
 430       if (Cache[I].Install() == true)
 431          Fix.Protect(I);
 432
 433       if (_config->FindB("APT::Ignore-Hold",false) == false)
 434          if (I->SelectedState == pkgCache::State::Hold)
 435             continue;
 436
 437       if (I->CurrentVer != 0 && Cache[I].InstallVer != 0)
 438          Cache.MarkInstall(I, false, 0, false);
 439    }
 440
 441    return Fix.ResolveByKeep();
 442 }
 443                                                                         /*}}}*/
 444 // MinimizeUpgrade - Minimizes the set of packages to be upgraded       /*{{{*/
 445 // ---------------------------------------------------------------------
 446 /* This simply goes over the entire set of packages and tries to keep
 447    each package marked for upgrade. If a conflict is generated then
 448    the package is restored. */
 449 bool pkgMinimizeUpgrade(pkgDepCache &Cache)
 450 {
 451    pkgDepCache::ActionGroup group(Cache);
 452
 453    if (Cache.BrokenCount() != 0)
 454       return false;
 455
 456    // We loop for 10 tries to get the minimal set size.
 457    bool Change = false;
 458    unsigned int Count = 0;
 459    do
 460    {
 461       Change = false;
 462       for (pkgCache::PkgIterator I = Cache.PkgBegin(); I.end() == false; I++)
 463       {
 464          // Not interesting
 465          if (Cache[I].Upgrade() == false || Cache[I].NewInstall() == true)
 466             continue;
 467
 468          // Keep it and see if that is OK
 469          Cache.MarkKeep(I, false, false);
 470          if (Cache.BrokenCount() != 0)
 471             Cache.MarkInstall(I, false, 0, false);
 472          else
 473          {
 474             // If keep didnt actually do anything then there was no change..
 475             if (Cache[I].Upgrade() == false)
 476                Change = true;
 477          }
 478       }
 479       Count++;
 480    }
 481    while (Change == true && Count < 10);
 482
 483    if (Cache.BrokenCount() != 0)
 484       return _error->Error("Internal Error in pkgMinimizeUpgrade");
 485
 486    return true;
 487 }
 488                                                                         /*}}}*/
 489 // ProblemResolver::pkgProblemResolver - Constructor                    /*{{{*/
 490 // ---------------------------------------------------------------------
 491 /* */
 492 pkgProblemResolver::pkgProblemResolver(pkgDepCache *pCache) : Cache(*pCache)
 493 {
 494    // Allocate memory
 495    unsigned long Size = Cache.Head().PackageCount;
 496    Scores = new signed short[Size];
 497    Flags = new unsigned char[Size];
 498    memset(Flags,0,sizeof(*Flags)*Size);
 499
 500    // Set debug to true to see its decision logic
 501    Debug = _config->FindB("Debug::pkgProblemResolver",false);
 502 }
 503                                                                         /*}}}*/
 504 // ProblemResolver::~pkgProblemResolver - Destructor                    /*{{{*/
 505 // ---------------------------------------------------------------------
 506 /* */
 507 pkgProblemResolver::~pkgProblemResolver()
 508 {
 509    delete [] Scores;
 510    delete [] Flags;
 511 }
 512                                                                         /*}}}*/
 513 // ProblemResolver::ScoreSort - Sort the list by score                  /*{{{*/
 514 // ---------------------------------------------------------------------
 515 /* */
 516 int pkgProblemResolver::ScoreSort(const void *a,const void *b)
 517 {
 518    Package const **A = (Package const **)a;
 519    Package const **B = (Package const **)b;
 520    if (This->Scores[(*A)->ID] > This->Scores[(*B)->ID])
 521       return -1;
 522    if (This->Scores[(*A)->ID] < This->Scores[(*B)->ID])
 523       return 1;
 524    return 0;
 525 }
 526                                                                         /*}}}*/
 527 // ProblemResolver::MakeScores - Make the score table                   /*{{{*/
 528 // ---------------------------------------------------------------------
 529 /* */
 530 void pkgProblemResolver::MakeScores()
 531 {
 532    unsigned long Size = Cache.Head().PackageCount;
 533    memset(Scores,0,sizeof(*Scores)*Size);
 534
 535    // Important Required Standard Optional Extra
 536    signed short PrioMap[] = {
 537       0,
 538       (signed short) _config->FindI("pkgProblemResolver::Scores::Important",3),
 539       (signed short) _config->FindI("pkgProblemResolver::Scores::Required",2),
 540       (signed short) _config->FindI("pkgProblemResolver::Scores::Standard",1),
 541       (signed short) _config->FindI("pkgProblemResolver::Scores::Optional",-1),
 542       (signed short) _config->FindI("pkgProblemResolver::Scores::Extra",-2)
 543    };
 544    signed short PrioEssentials = _config->FindI("pkgProblemResolver::Scores::Essentials",100);
 545    signed short PrioInstalledAndNotObsolete = _config->FindI("pkgProblemResolver::Scores::NotObsolete",1);
 546    signed short PrioDepends = _config->FindI("pkgProblemResolver::Scores::Depends",1);
 547    signed short PrioRecommends = _config->FindI("pkgProblemResolver::Scores::Recommends",1);
 548    signed short AddProtected = _config->FindI("pkgProblemResolver::Scores::AddProtected",10000);
 549    signed short AddEssential = _config->FindI("pkgProblemResolver::Scores::AddEssential",5000);
 550
 551    if (_config->FindB("Debug::pkgProblemResolver::ShowScores",false) == true)
 552       clog << "Settings used to calculate pkgProblemResolver::Scores::" << endl
 553          << "  Important => " << PrioMap[1] << endl
 554          << "  Required => " << PrioMap[2] << endl
 555          << "  Standard => " << PrioMap[3] << endl
 556          << "  Optional => " << PrioMap[4] << endl
 557          << "  Extra => " << PrioMap[5] << endl
 558          << "  Essentials => " << PrioEssentials << endl
 559          << "  InstalledAndNotObsolete => " << PrioInstalledAndNotObsolete << endl
 560          << "  Depends => " << PrioDepends << endl
 561          << "  Recommends => " << PrioRecommends << endl
 562          << "  AddProtected => " << AddProtected << endl
 563          << "  AddEssential => " << AddEssential << endl;
 564
 565    // Generate the base scores for a package based on its properties
 566    for (pkgCache::PkgIterator I = Cache.PkgBegin(); I.end() == false; I++)
 567    {
 568       if (Cache[I].InstallVer == 0)
 569          continue;
 570
 571       signed short &Score = Scores[I->ID];
 572
 573       /* This is arbitrary, it should be high enough to elevate an
 574          essantial package above most other packages but low enough
 575          to allow an obsolete essential packages to be removed by
 576          a conflicts on a powerfull normal package (ie libc6) */
 577       if ((I->Flags & pkgCache::Flag::Essential) == pkgCache::Flag::Essential)
 578          Score += PrioEssentials;
 579
 580       // We transform the priority
 581       if (Cache[I].InstVerIter(Cache)->Priority <= 5)
 582          Score += PrioMap[Cache[I].InstVerIter(Cache)->Priority];
 583
 584       /* This helps to fix oddball problems with conflicting packages
 585          on the same level. We enhance the score of installed packages
 586          if those are not obsolete
 587       */
 588       if (I->CurrentVer != 0 && Cache[I].CandidateVer != 0 && Cache[I].CandidateVerIter(Cache).Downloadable())
 589          Score += PrioInstalledAndNotObsolete;
 590    }
 591
 592    // Now that we have the base scores we go and propogate dependencies
 593    for (pkgCache::PkgIterator I = Cache.PkgBegin(); I.end() == false; I++)
 594    {
 595       if (Cache[I].InstallVer == 0)
 596          continue;
 597
 598       for (pkgCache::DepIterator D = Cache[I].InstVerIter(Cache).DependsList(); D.end() == false; D++)
 599       {
 600          if (D->Type == pkgCache::Dep::Depends ||
 601              D->Type == pkgCache::Dep::PreDepends)
 602             Scores[D.TargetPkg()->ID] += PrioDepends;
 603          else if (D->Type == pkgCache::Dep::Recommends)
 604             Scores[D.TargetPkg()->ID] += PrioRecommends;
 605       }
 606    }
 607
 608    // Copy the scores to advoid additive looping
 609    SPtrArray<signed short> OldScores = new signed short[Size];
 610    memcpy(OldScores,Scores,sizeof(*Scores)*Size);
 611
 612    /* Now we cause 1 level of dependency inheritance, that is we add the
 613       score of the packages that depend on the target Package. This
 614       fortifies high scoring packages */
 615    for (pkgCache::PkgIterator I = Cache.PkgBegin(); I.end() == false; I++)
 616    {
 617       if (Cache[I].InstallVer == 0)
 618          continue;
 619
 620       for (pkgCache::DepIterator D = I.RevDependsList(); D.end() == false; D++)
 621       {
 622          // Only do it for the install version
 623          if ((pkgCache::Version *)D.ParentVer() != Cache[D.ParentPkg()].InstallVer ||
 624              (D->Type != pkgCache::Dep::Depends &&
 625               D->Type != pkgCache::Dep::PreDepends &&
 626               D->Type != pkgCache::Dep::Recommends))
 627             continue;
 628
 629          Scores[I->ID] += abs(OldScores[D.ParentPkg()->ID]);
 630       }
 631    }
 632
 633    /* Now we propogate along provides. This makes the packages that
 634       provide important packages extremely important */
 635    for (pkgCache::PkgIterator I = Cache.PkgBegin(); I.end() == false; I++)
 636    {
 637       for (pkgCache::PrvIterator P = I.ProvidesList(); P.end() == false; P++)
 638       {
 639          // Only do it once per package
 640          if ((pkgCache::Version *)P.OwnerVer() != Cache[P.OwnerPkg()].InstallVer)
 641             continue;
 642          Scores[P.OwnerPkg()->ID] += abs(Scores[I->ID] - OldScores[I->ID]);
 643       }
 644    }
 645
 646    /* Protected things are pushed really high up. This number should put them
 647       ahead of everything */
 648    for (pkgCache::PkgIterator I = Cache.PkgBegin(); I.end() == false; I++)
 649    {
 650       if ((Flags[I->ID] & Protected) != 0)
 651          Scores[I->ID] += AddProtected;
 652       if ((I->Flags & pkgCache::Flag::Essential) == pkgCache::Flag::Essential)
 653          Scores[I->ID] += AddEssential;
 654    }
 655 }
 656                                                                         /*}}}*/
 657 // ProblemResolver::DoUpgrade - Attempt to upgrade this package         /*{{{*/
 658 // ---------------------------------------------------------------------
 659 /* This goes through and tries to reinstall packages to make this package
 660    installable */
 661 bool pkgProblemResolver::DoUpgrade(pkgCache::PkgIterator Pkg)
 662 {
 663    pkgDepCache::ActionGroup group(Cache);
 664
 665    if ((Flags[Pkg->ID] & Upgradable) == 0 || Cache[Pkg].Upgradable() == false)
 666       return false;
 667    if ((Flags[Pkg->ID] & Protected) == Protected)
 668       return false;
 669
 670    Flags[Pkg->ID] &= ~Upgradable;
 671
 672    bool WasKept = Cache[Pkg].Keep();
 673    Cache.MarkInstall(Pkg, false, 0, false);
 674
 675    // This must be a virtual package or something like that.
 676    if (Cache[Pkg].InstVerIter(Cache).end() == true)
 677       return false;
 678
 679    // Isolate the problem dependency
 680    bool Fail = false;
 681    for (pkgCache::DepIterator D = Cache[Pkg].InstVerIter(Cache).DependsList(); D.end() == false;)
 682    {
 683       // Compute a single dependency element (glob or)
 684       pkgCache::DepIterator Start = D;
 685       pkgCache::DepIterator End = D;
 686       unsigned char State = 0;
 687       for (bool LastOR = true; D.end() == false && LastOR == true;)
 688       {
 689          State |= Cache[D];
 690          LastOR = (D->CompareOp & pkgCache::Dep::Or) == pkgCache::Dep::Or;
 691          D++;
 692          if (LastOR == true)
 693             End = D;
 694       }
 695
 696       // We only worry about critical deps.
 697       if (End.IsCritical() != true)
 698          continue;
 699
 700       // Iterate over all the members in the or group
 701       while (1)
 702       {
 703          // Dep is ok now
 704          if ((Cache[End] & pkgDepCache::DepGInstall) == pkgDepCache::DepGInstall)
 705             break;
 706
 707          // Do not change protected packages
 708          PkgIterator P = Start.SmartTargetPkg();
 709          if ((Flags[P->ID] & Protected) == Protected)
 710          {
 711             if (Debug == true)
 712                clog << "    Reinst Failed because of protected " << P.Name() << endl;
 713             Fail = true;
 714          }
 715          else
 716          {
 717             // Upgrade the package if the candidate version will fix the problem.
 718             if ((Cache[Start] & pkgDepCache::DepCVer) == pkgDepCache::DepCVer)
 719             {
 720                if (DoUpgrade(P) == false)
 721                {
 722                   if (Debug == true)
 723                      clog << "    Reinst Failed because of " << P.Name() << endl;
 724                   Fail = true;
 725                }
 726                else
 727                {
 728                   Fail = false;
 729                   break;
 730                }
 731             }
 732             else
 733             {
 734                /* We let the algorithm deal with conflicts on its next iteration,
 735                 it is much smarter than us */
 736                if (Start->Type == pkgCache::Dep::Conflicts ||
 737                    Start->Type == pkgCache::Dep::DpkgBreaks ||
 738                    Start->Type == pkgCache::Dep::Obsoletes)
 739                    break;
 740
 741                if (Debug == true)
 742                   clog << "    Reinst Failed early because of " << Start.TargetPkg().Name() << endl;
 743                Fail = true;
 744             }
 745          }
 746
 747          if (Start == End)
 748             break;
 749          Start++;
 750       }
 751       if (Fail == true)
 752          break;
 753    }
 754
 755    // Undo our operations - it might be smart to undo everything this did..
 756    if (Fail == true)
 757    {
 758       if (WasKept == true)
 759          Cache.MarkKeep(Pkg, false, false);
 760       else
 761          Cache.MarkDelete(Pkg);
 762       return false;
 763    }
 764
 765    if (Debug == true)
 766       clog << "  Re-Instated " << Pkg.Name() << endl;
 767    return true;
 768 }
 769                                                                         /*}}}*/
 770 // ProblemResolver::Resolve - Run the resolution pass                   /*{{{*/
 771 // ---------------------------------------------------------------------
 772 /* This routines works by calculating a score for each package. The score
 773    is derived by considering the package's priority and all reverse
 774    dependents giving an integer that reflects the amount of breakage that
 775    adjusting the package will inflict.
 776
 777    It goes from highest score to lowest and corrects all of the breaks by
 778    keeping or removing the dependant packages. If that fails then it removes
 779    the package itself and goes on. The routine should be able to intelligently
 780    go from any broken state to a fixed state.
 781
 782    The BrokenFix flag enables a mode where the algorithm tries to
 783    upgrade packages to advoid problems. */
 784 bool pkgProblemResolver::Resolve(bool BrokenFix)
 785 {
 786    pkgDepCache::ActionGroup group(Cache);
 787
 788    unsigned long Size = Cache.Head().PackageCount;
 789
 790    // Record which packages are marked for install
 791    bool Again = false;
 792    do
 793    {
 794       Again = false;
 795       for (pkgCache::PkgIterator I = Cache.PkgBegin(); I.end() == false; I++)
 796       {
 797          if (Cache[I].Install() == true)
 798             Flags[I->ID] |= PreInstalled;
 799          else
 800          {
 801             if (Cache[I].InstBroken() == true && BrokenFix == true)
 802             {
 803                Cache.MarkInstall(I, false, 0, false);
 804                if (Cache[I].Install() == true)
 805                   Again = true;
 806             }
 807
 808             Flags[I->ID] &= ~PreInstalled;
 809          }
 810          Flags[I->ID] |= Upgradable;
 811       }
 812    }
 813    while (Again == true);
 814
 815    if (Debug == true)
 816       clog << "Starting" << endl;
 817
 818    MakeScores();
 819
 820    /* We have to order the packages so that the broken fixing pass
 821       operates from highest score to lowest. This prevents problems when
 822       high score packages cause the removal of lower score packages that
 823       would cause the removal of even lower score packages. */
 824    SPtrArray<pkgCache::Package *> PList = new pkgCache::Package *[Size];
 825    pkgCache::Package **PEnd = PList;
 826    for (pkgCache::PkgIterator I = Cache.PkgBegin(); I.end() == false; I++)
 827       *PEnd++ = I;
 828    This = this;
 829    qsort(PList,PEnd - PList,sizeof(*PList),&ScoreSort);
 830
 831    if (_config->FindB("Debug::pkgProblemResolver::ShowScores",false) == true)
 832    {
 833       clog << "Show Scores" << endl;
 834       for (pkgCache::Package **K = PList; K != PEnd; K++)
 835          if (Scores[(*K)->ID] != 0)
 836          {
 837            pkgCache::PkgIterator Pkg(Cache,*K);
 838            clog << Scores[(*K)->ID] << ' ' << Pkg << std::endl;
 839          }
 840    }
 841
 842    if (Debug == true)
 843       clog << "Starting 2" << endl;
 844
 845    /* Now consider all broken packages. For each broken package we either
 846       remove the package or fix it's problem. We do this once, it should
 847       not be possible for a loop to form (that is a < b < c and fixing b by
 848       changing a breaks c) */
 849    bool Change = true;
 850    for (int Counter = 0; Counter != 10 && Change == true; Counter++)
 851    {
 852       Change = false;
 853       for (pkgCache::Package **K = PList; K != PEnd; K++)
 854       {
 855          pkgCache::PkgIterator I(Cache,*K);
 856
 857          /* We attempt to install this and see if any breaks result,
 858             this takes care of some strange cases */
 859          if (Cache[I].CandidateVer != Cache[I].InstallVer &&
 860              I->CurrentVer != 0 && Cache[I].InstallVer != 0 &&
 861              (Flags[I->ID] & PreInstalled) != 0 &&
 862              (Flags[I->ID] & Protected) == 0 &&
 863              (Flags[I->ID] & ReInstateTried) == 0)
 864          {
 865             if (Debug == true)
 866                clog << " Try to Re-Instate " << I.Name() << endl;
 867             unsigned long OldBreaks = Cache.BrokenCount();
 868             pkgCache::Version *OldVer = Cache[I].InstallVer;
 869             Flags[I->ID] &= ReInstateTried;
 870
 871             Cache.MarkInstall(I, false, 0, false);
 872             if (Cache[I].InstBroken() == true ||
 873                 OldBreaks < Cache.BrokenCount())
 874             {
 875                if (OldVer == 0)
 876                   Cache.MarkDelete(I);
 877                else
 878                   Cache.MarkKeep(I, false, false);
 879             }
 880             else
 881                if (Debug == true)
 882                   clog << "Re-Instated " << I.Name() << " (" << OldBreaks << " vs " << Cache.BrokenCount() << ')' << endl;
 883          }
 884
 885          if (Cache[I].InstallVer == 0 || Cache[I].InstBroken() == false)
 886             continue;
 887
 888          if (Debug == true)
 889             clog << "Investigating " << I.Name() << endl;
 890
 891          // Isolate the problem dependency
 892          PackageKill KillList[100];
 893          PackageKill *LEnd = KillList;
 894          bool InOr = false;
 895          pkgCache::DepIterator Start;
 896          pkgCache::DepIterator End;
 897          PackageKill *OldEnd = LEnd;
 898
 899          enum {OrRemove,OrKeep} OrOp = OrRemove;
 900          for (pkgCache::DepIterator D = Cache[I].InstVerIter(Cache).DependsList();
 901               D.end() == false || InOr == true;)
 902          {
 903             // Compute a single dependency element (glob or)
 904             if (Start == End)
 905             {
 906                // Decide what to do
 907                if (InOr == true)
 908                {
 909                   if (OldEnd == LEnd && OrOp == OrRemove)
 910                   {
 911                      if ((Flags[I->ID] & Protected) != Protected)
 912                      {
 913                         if (Debug == true)
 914                            clog << "  Or group remove for " << I.Name() << endl;
 915                         Cache.MarkDelete(I);
 916                         Change = true;
 917                      }
 918                   }
 919                   if (OldEnd == LEnd && OrOp == OrKeep)
 920                   {
 921                      if (Debug == true)
 922                         clog << "  Or group keep for " << I.Name() << endl;
 923                      Cache.MarkKeep(I, false, false);
 924                      Change = true;
 925                   }
 926                }
 927
 928                /* We do an extra loop (as above) to finalize the or group
 929                   processing */
 930                InOr = false;
 931                OrOp = OrRemove;
 932                D.GlobOr(Start,End);
 933                if (Start.end() == true)
 934                   break;
 935
 936                // We only worry about critical deps.
 937                if (End.IsCritical() != true)
 938                   continue;
 939
 940                InOr = Start != End;
 941                OldEnd = LEnd;
 942             }
 943             else
 944             {
 945                Start++;
 946                // We only worry about critical deps.
 947                if (Start.IsCritical() != true)
 948                   continue;
 949             }
 950
 951             // Dep is ok
 952             if ((Cache[End] & pkgDepCache::DepGInstall) == pkgDepCache::DepGInstall)
 953             {
 954                InOr = false;
 955                continue;
 956             }
 957
 958             if (Debug == true)
 959                clog << "Package " << I.Name() << " has broken " << Start.DepType() << " on " << Start.TargetPkg().Name() << endl;
 960
 961             /* Look across the version list. If there are no possible
 962                targets then we keep the package and bail. This is necessary
 963                if a package has a dep on another package that cant be found */
 964             SPtrArray<pkgCache::Version *> VList = Start.AllTargets();
 965             if (*VList == 0 && (Flags[I->ID] & Protected) != Protected &&
 966                 Start->Type != pkgCache::Dep::Conflicts &&
 967                 Start->Type != pkgCache::Dep::DpkgBreaks &&
 968                 Start->Type != pkgCache::Dep::Obsoletes &&
 969                 Cache[I].NowBroken() == false)
 970             {
 971                if (InOr == true)
 972                {
 973                   /* No keep choice because the keep being OK could be the
 974                      result of another element in the OR group! */
 975                   continue;
 976                }
 977
 978                Change = true;
 979                Cache.MarkKeep(I, false, false);
 980                break;
 981             }
 982
 983             bool Done = false;
 984             for (pkgCache::Version **V = VList; *V != 0; V++)
 985             {
 986                pkgCache::VerIterator Ver(Cache,*V);
 987                pkgCache::PkgIterator Pkg = Ver.ParentPkg();
 988
 989                if (Debug == true)
 990                   clog << "  Considering " << Pkg.Name() << ' ' << (int)Scores[Pkg->ID] <<
 991                   " as a solution to " << I.Name() << ' ' << (int)Scores[I->ID] << endl;
 992
 993                /* Try to fix the package under consideration rather than
 994                   fiddle with the VList package */
 995                if (Scores[I->ID] <= Scores[Pkg->ID] ||
 996                    ((Cache[Start] & pkgDepCache::DepNow) == 0 &&
 997                     End->Type != pkgCache::Dep::Conflicts &&
 998                     End->Type != pkgCache::Dep::DpkgBreaks &&
 999                     End->Type != pkgCache::Dep::Obsoletes))
1000                {
1001                   // Try a little harder to fix protected packages..
1002                   if ((Flags[I->ID] & Protected) == Protected)
1003                   {
1004                      if (DoUpgrade(Pkg) == true)
1005                      {
1006                         if (Scores[Pkg->ID] > Scores[I->ID])
1007                            Scores[Pkg->ID] = Scores[I->ID];
1008                         break;
1009                      }
1010
1011                      continue;
1012                   }
1013
1014                   /* See if a keep will do, unless the package is protected,
1015                      then installing it will be necessary */
1016                   bool Installed = Cache[I].Install();
1017                   Cache.MarkKeep(I, false, false);
1018                   if (Cache[I].InstBroken() == false)
1019                   {
1020                      // Unwind operation will be keep now
1021                      if (OrOp == OrRemove)
1022                         OrOp = OrKeep;
1023
1024                      // Restore
1025                      if (InOr == true && Installed == true)
1026                         Cache.MarkInstall(I, false, 0, false);
1027
1028                      if (Debug == true)
1029                         clog << "  Holding Back " << I.Name() << " rather than change " << Start.TargetPkg().Name() << endl;
1030                   }
1031                   else
1032                   {
1033                      if (BrokenFix == false || DoUpgrade(I) == false)
1034                      {
1035                         // Consider other options
1036                         if (InOr == false)
1037                         {
1038                            if (Debug == true)
1039                               clog << "  Removing " << I.Name() << " rather than change " << Start.TargetPkg().Name() << endl;
1040                            Cache.MarkDelete(I);
1041                            if (Counter > 1 && Scores[Pkg->ID] > Scores[I->ID])
1042                               Scores[I->ID] = Scores[Pkg->ID];
1043                         }
1044                      }
1045                   }
1046
1047                   Change = true;
1048                   Done = true;
1049                   break;
1050                }
1051                else
1052                {
1053                   /* This is a conflicts, and the version we are looking
1054                      at is not the currently selected version of the
1055                      package, which means it is not necessary to
1056                      remove/keep */
1057                   if (Cache[Pkg].InstallVer != Ver &&
1058                       (Start->Type == pkgCache::Dep::Conflicts ||
1059                        Start->Type == pkgCache::Dep::Obsoletes))
1060                      continue;
1061
1062                   if (Start->Type == pkgCache::Dep::DpkgBreaks)
1063                   {
1064                      // first, try upgradring the package, if that
1065                      // does not help, the breaks goes onto the
1066                      // kill list
1067                      // FIXME: use DoUpgrade(Pkg) instead?
1068                      if (Cache[End] & pkgDepCache::DepGCVer)
1069                      {
1070                         if (Debug)
1071                            clog << "  Upgrading " << Pkg.Name() << " due to Breaks field in " << I.Name() << endl;
1072                         Cache.MarkInstall(Pkg, false, 0, false);
1073                         continue;
1074                      }
1075                   }
1076
1077                   // Skip adding to the kill list if it is protected
1078                   if ((Flags[Pkg->ID] & Protected) != 0)
1079                      continue;
1080
1081                   if (Debug == true)
1082                      clog << "  Added " << Pkg.Name() << " to the remove list" << endl;
1083
1084                   LEnd->Pkg = Pkg;
1085                   LEnd->Dep = End;
1086                   LEnd++;
1087
1088                   if (Start->Type != pkgCache::Dep::Conflicts &&
1089                       Start->Type != pkgCache::Dep::Obsoletes)
1090                      break;
1091                }
1092             }
1093
1094             // Hm, nothing can possibly satisify this dep. Nuke it.
1095             if (VList[0] == 0 &&
1096                 Start->Type != pkgCache::Dep::Conflicts &&
1097                 Start->Type != pkgCache::Dep::DpkgBreaks &&
1098                 Start->Type != pkgCache::Dep::Obsoletes &&
1099                 (Flags[I->ID] & Protected) != Protected)
1100             {
1101                bool Installed = Cache[I].Install();
1102                Cache.MarkKeep(I);
1103                if (Cache[I].InstBroken() == false)
1104                {
1105                   // Unwind operation will be keep now
1106                   if (OrOp == OrRemove)
1107                      OrOp = OrKeep;
1108
1109                   // Restore
1110                   if (InOr == true && Installed == true)
1111                      Cache.MarkInstall(I, false, 0, false);
1112
1113                   if (Debug == true)
1114                      clog << "  Holding Back " << I.Name() << " because I can't find " << Start.TargetPkg().Name() << endl;
1115                }
1116                else
1117                {
1118                   if (Debug == true)
1119                      clog << "  Removing " << I.Name() << " because I can't find " << Start.TargetPkg().Name() << endl;
1120                   if (InOr == false)
1121                      Cache.MarkDelete(I);
1122                }
1123
1124                Change = true;
1125                Done = true;
1126             }
1127
1128             // Try some more
1129             if (InOr == true)
1130                continue;
1131
1132             if (Done == true)
1133                break;
1134          }
1135
1136          // Apply the kill list now
1137          if (Cache[I].InstallVer != 0)
1138          {
1139             for (PackageKill *J = KillList; J != LEnd; J++)
1140             {
1141                Change = true;
1142                if ((Cache[J->Dep] & pkgDepCache::DepGNow) == 0)
1143                {
1144                   if (J->Dep->Type == pkgCache::Dep::Conflicts ||
1145                       J->Dep->Type == pkgCache::Dep::DpkgBreaks ||
1146                       J->Dep->Type == pkgCache::Dep::Obsoletes)
1147                   {
1148                      if (Debug == true)
1149                         clog << "  Fixing " << I.Name() << " via remove of " << J->Pkg.Name() << endl;
1150                      Cache.MarkDelete(J->Pkg);
1151                   }
1152                }
1153                else
1154                {
1155                   if (Debug == true)
1156                      clog << "  Fixing " << I.Name() << " via keep of " << J->Pkg.Name() << endl;
1157                   Cache.MarkKeep(J->Pkg, false, false);
1158                }
1159
1160                if (Counter > 1)
1161                {
1162                   if (Scores[I->ID] > Scores[J->Pkg->ID])
1163                      Scores[J->Pkg->ID] = Scores[I->ID];
1164                }
1165             }
1166          }
1167       }
1168    }
1169
1170    if (Debug == true)
1171       clog << "Done" << endl;
1172
1173    if (Cache.BrokenCount() != 0)
1174    {
1175       // See if this is the result of a hold
1176       pkgCache::PkgIterator I = Cache.PkgBegin();
1177       for (;I.end() != true; I++)
1178       {
1179          if (Cache[I].InstBroken() == false)
1180             continue;
1181          if ((Flags[I->ID] & Protected) != Protected)
1182             return _error->Error(_("Error, pkgProblemResolver::Resolve generated breaks, this may be caused by held packages."));
1183       }
1184       return _error->Error(_("Unable to correct problems, you have held broken packages."));
1185    }
1186
1187    // set the auto-flags (mvo: I'm not sure if we _really_ need this, but
1188    // I didn't managed
1189    pkgCache::PkgIterator I = Cache.PkgBegin();
1190    for (;I.end() != true; I++) {
1191       if (Cache[I].NewInstall() && !(Flags[I->ID] & PreInstalled)) {
1192          if(_config->FindI("Debug::pkgAutoRemove",false)) {
1193             std::clog << "Resolve installed new pkg: " << I.Name()
1194                       << " (now marking it as auto)" << std::endl;
1195          }
1196          Cache[I].Flags |= pkgCache::Flag::Auto;
1197       }
1198    }
1199
1200
1201    return true;
1202 }
1203                                                                         /*}}}*/
1204 // ProblemResolver::ResolveByKeep - Resolve problems using keep         /*{{{*/
1205 // ---------------------------------------------------------------------
1206 /* This is the work horse of the soft upgrade routine. It is very gental
1207    in that it does not install or remove any packages. It is assumed that the
1208    system was non-broken previously. */
1209 bool pkgProblemResolver::ResolveByKeep()
1210 {
1211    pkgDepCache::ActionGroup group(Cache);
1212
1213    unsigned long Size = Cache.Head().PackageCount;
1214
1215    MakeScores();
1216
1217    /* We have to order the packages so that the broken fixing pass
1218       operates from highest score to lowest. This prevents problems when
1219       high score packages cause the removal of lower score packages that
1220       would cause the removal of even lower score packages. */
1221    pkgCache::Package **PList = new pkgCache::Package *[Size];
1222    pkgCache::Package **PEnd = PList;
1223    for (pkgCache::PkgIterator I = Cache.PkgBegin(); I.end() == false; I++)
1224       *PEnd++ = I;
1225    This = this;
1226    qsort(PList,PEnd - PList,sizeof(*PList),&ScoreSort);
1227
1228    if (_config->FindB("Debug::pkgProblemResolver::ShowScores",false) == true)
1229    {
1230       clog << "Show Scores" << endl;
1231       for (pkgCache::Package **K = PList; K != PEnd; K++)
1232          if (Scores[(*K)->ID] != 0)
1233          {
1234            pkgCache::PkgIterator Pkg(Cache,*K);
1235            clog << Scores[(*K)->ID] << ' ' << Pkg << std::endl;
1236          }
1237    }
1238
1239    if (Debug == true)
1240       clog << "Entering ResolveByKeep" << endl;
1241
1242    // Consider each broken package
1243    pkgCache::Package **LastStop = 0;
1244    for (pkgCache::Package **K = PList; K != PEnd; K++)
1245    {
1246       pkgCache::PkgIterator I(Cache,*K);
1247
1248       if (Cache[I].InstallVer == 0 || Cache[I].InstBroken() == false)
1249          continue;
1250
1251       /* Keep the package. If this works then great, otherwise we have
1252          to be significantly more agressive and manipulate its dependencies */
1253       if ((Flags[I->ID] & Protected) == 0)
1254       {
1255          if (Debug == true)
1256             clog << "Keeping package " << I.Name() << endl;
1257          Cache.MarkKeep(I, false, false);
1258          if (Cache[I].InstBroken() == false)
1259          {
1260             K = PList - 1;
1261             continue;
1262          }
1263       }
1264
1265       // Isolate the problem dependencies
1266       for (pkgCache::DepIterator D = Cache[I].InstVerIter(Cache).DependsList(); D.end() == false;)
1267       {
1268          DepIterator Start;
1269          DepIterator End;
1270          D.GlobOr(Start,End);
1271
1272          // We only worry about critical deps.
1273          if (End.IsCritical() != true)
1274             continue;
1275
1276          // Dep is ok
1277          if ((Cache[End] & pkgDepCache::DepGInstall) == pkgDepCache::DepGInstall)
1278             continue;
1279
1280          /* Hm, the group is broken.. I suppose the best thing to do is to
1281             is to try every combination of keep/not-keep for the set, but thats
1282             slow, and this never happens, just be conservative and assume the
1283             list of ors is in preference and keep till it starts to work. */
1284          while (true)
1285          {
1286             if (Debug == true)
1287                clog << "Package " << I.Name() << " has broken " << Start.DepType() << " on " << Start.TargetPkg().Name() << endl;
1288
1289             // Look at all the possible provides on this package
1290             SPtrArray<pkgCache::Version *> VList = Start.AllTargets();
1291             for (pkgCache::Version **V = VList; *V != 0; V++)
1292             {
1293                pkgCache::VerIterator Ver(Cache,*V);
1294                pkgCache::PkgIterator Pkg = Ver.ParentPkg();
1295
1296                // It is not keepable
1297                if (Cache[Pkg].InstallVer == 0 ||
1298                    Pkg->CurrentVer == 0)
1299                   continue;
1300
1301                if ((Flags[I->ID] & Protected) == 0)
1302                {
1303                   if (Debug == true)
1304                      clog << "  Keeping Package " << Pkg.Name() << " due to " << Start.DepType() << endl;
1305                   Cache.MarkKeep(Pkg, false, false);
1306                }
1307
1308                if (Cache[I].InstBroken() == false)
1309                   break;
1310             }
1311
1312             if (Cache[I].InstBroken() == false)
1313                break;
1314
1315             if (Start == End)
1316                break;
1317             Start++;
1318          }
1319
1320          if (Cache[I].InstBroken() == false)
1321             break;
1322       }
1323
1324       if (Cache[I].InstBroken() == true)
1325          continue;
1326
1327       // Restart again.
1328       if (K == LastStop)
1329          return _error->Error("Internal Error, pkgProblemResolver::ResolveByKeep is looping on package %s.",I.Name());
1330       LastStop = K;
1331       K = PList - 1;
1332    }
1333
1334    return true;
1335 }
1336                                                                         /*}}}*/
1337 // ProblemResolver::InstallProtect - Install all protected packages     /*{{{*/
1338 // ---------------------------------------------------------------------
1339 /* This is used to make sure protected packages are installed */
1340 void pkgProblemResolver::InstallProtect()
1341 {
1342    pkgDepCache::ActionGroup group(Cache);
1343
1344    for (pkgCache::PkgIterator I = Cache.PkgBegin(); I.end() == false; I++)
1345    {
1346       if ((Flags[I->ID] & Protected) == Protected)
1347       {
1348          if ((Flags[I->ID] & ToRemove) == ToRemove)
1349             Cache.MarkDelete(I);
1350          else
1351          {
1352             // preserve the information whether the package was auto
1353             // or manually installed
1354             bool autoInst = (Cache[I].Flags & pkgCache::Flag::Auto);
1355             Cache.MarkInstall(I, false, 0, !autoInst);
1356          }
1357       }
1358    }
1359 }
1360                                                                         /*}}}*/
1361 // PrioSortList - Sort a list of versions by priority                   /*{{{*/
1362 // ---------------------------------------------------------------------
1363 /* This is ment to be used in conjunction with AllTargets to get a list
1364    of versions ordered by preference. */
1365 static pkgCache *PrioCache;
1366 static int PrioComp(const void *A,const void *B)
1367 {
1368    pkgCache::VerIterator L(*PrioCache,*(pkgCache::Version **)A);
1369    pkgCache::VerIterator R(*PrioCache,*(pkgCache::Version **)B);
1370
1371    if ((L.ParentPkg()->Flags & pkgCache::Flag::Essential) == pkgCache::Flag::Essential &&
1372        (R.ParentPkg()->Flags & pkgCache::Flag::Essential) != pkgCache::Flag::Essential)
1373      return 1;
1374    if ((L.ParentPkg()->Flags & pkgCache::Flag::Essential) != pkgCache::Flag::Essential &&
1375        (R.ParentPkg()->Flags & pkgCache::Flag::Essential) == pkgCache::Flag::Essential)
1376      return -1;
1377
1378    if (L->Priority != R->Priority)
1379       return R->Priority - L->Priority;
1380    return strcmp(L.ParentPkg().Name(),R.ParentPkg().Name());
1381 }
1382 void pkgPrioSortList(pkgCache &Cache,pkgCache::Version **List)
1383 {
1384    unsigned long Count = 0;
1385    PrioCache = &Cache;
1386    for (pkgCache::Version **I = List; *I != 0; I++)
1387       Count++;
1388    qsort(List,Count,sizeof(*List),PrioComp);
1389 }
1390                                                                         /*}}}*/
1391 // CacheFile::ListUpdate - update the cache files                       /*{{{*/
1392 // ---------------------------------------------------------------------
1393 /* This is a simple wrapper to update the cache. it will fetch stuff
1394  * from the network (or any other sources defined in sources.list)
1395  */
1396 bool ListUpdate(pkgAcquireStatus &Stat,
1397                 pkgSourceList &List,
1398                 int PulseInterval)
1399 {
1400    pkgAcquire::RunResult res;
1401    pkgAcquire Fetcher(&Stat);
1402
1403    // Populate it with the source selection
1404    if (List.GetIndexes(&Fetcher) == false)
1405          return false;
1406
1407    // Run scripts
1408    RunScripts("APT::Update::Pre-Invoke");
1409
1410    // check arguments
1411    if(PulseInterval>0)
1412       res = Fetcher.Run(PulseInterval);
1413    else
1414       res = Fetcher.Run();
1415
1416    if (res == pkgAcquire::Failed)
1417       return false;
1418
1419    bool Failed = false;
1420    bool TransientNetworkFailure = false;
1421    for (pkgAcquire::ItemIterator I = Fetcher.ItemsBegin();
1422         I != Fetcher.ItemsEnd(); I++)
1423    {
1424       if ((*I)->Status == pkgAcquire::Item::StatDone)
1425          continue;
1426
1427       (*I)->Finished();
1428
1429       ::URI uri((*I)->DescURI());
1430       uri.User.clear();
1431       uri.Password.clear();
1432       string descUri = string(uri);
1433       _error->Warning(_("Failed to fetch %s  %s\n"), descUri.c_str(),
1434               (*I)->ErrorText.c_str());
1435
1436       if ((*I)->Status == pkgAcquire::Item::StatTransientNetworkError)
1437       {
1438          TransientNetworkFailure = true;
1439          continue;
1440       }
1441
1442       Failed = true;
1443    }
1444
1445    // Clean out any old list files
1446    // Keep "APT::Get::List-Cleanup" name for compatibility, but
1447    // this is really a global option for the APT library now
1448    if (!TransientNetworkFailure && !Failed &&
1449        (_config->FindB("APT::Get::List-Cleanup",true) == true &&
1450         _config->FindB("APT::List-Cleanup",true) == true))
1451    {
1452       if (Fetcher.Clean(_config->FindDir("Dir::State::lists")) == false ||
1453           Fetcher.Clean(_config->FindDir("Dir::State::lists") + "partial/") == false)
1454          // something went wrong with the clean
1455          return false;
1456    }
1457
1458    if (TransientNetworkFailure == true)
1459       _error->Warning(_("Some index files failed to download, they have been ignored, or old ones used instead."));
1460    else if (Failed == true)
1461       return _error->Error(_("Some index files failed to download, they have been ignored, or old ones used instead."));
1462
1463
1464    // Run the success scripts if all was fine
1465    if(!TransientNetworkFailure && !Failed)
1466       RunScripts("APT::Update::Post-Invoke-Success");
1467
1468    // Run the other scripts
1469    RunScripts("APT::Update::Post-Invoke");
1470    return true;
1471 }
1472                                                                         /*}}}*/