[apt.git] / apt-private / private-cacheset.cc

#include <config.h>

#include <apt-pkg/cachefile.h>
#include <apt-pkg/pkgcache.h>
#include <apt-pkg/depcache.h>
#include <apt-pkg/cacheiterators.h>
#include <apt-pkg/aptconfiguration.h>
#include <apt-pkg/configuration.h>
#include <apt-pkg/progress.h>
#include <apt-pkg/policy.h>
#include <apt-pkg/strutl.h>

#include <apt-private/private-cacheset.h>

#include <stddef.h>

#include <apti18n.h>

bool GetLocalitySortedVersionSet(pkgCacheFile &CacheFile,		/*{{{*/
                                 APT::VersionContainerInterface * const vci,
                                 OpProgress * const progress)
{
    Matcher null_matcher = Matcher();
    return GetLocalitySortedVersionSet(CacheFile, vci,
                                       null_matcher, progress);
}
bool GetLocalitySortedVersionSet(pkgCacheFile &CacheFile,
                                 APT::VersionContainerInterface * const vci,
                                 Matcher &matcher,
                                 OpProgress * const progress)
{
   pkgCache *Cache = CacheFile.GetPkgCache();
   pkgDepCache *DepCache = CacheFile.GetDepCache();
   APT::CacheSetHelper helper(false);

   int Done=0;
   if (progress != NULL)
      progress->SubProgress(Cache->Head().PackageCount, _("Sorting"));

   bool const insertCurrentVer = _config->FindB("APT::Cmd::Installed", false);
   bool const insertUpgradable = _config->FindB("APT::Cmd::Upgradable", false);
   bool const insertManualInstalled = _config->FindB("APT::Cmd::Manual-Installed", false);

   for (pkgCache::PkgIterator P = Cache->PkgBegin(); P.end() == false; ++P)
   {
      if (progress != NULL)
      {
	 if (Done % 500 == 0)
	    progress->Progress(Done);
	 ++Done;
      }

      // exclude virtual pkgs
      if (P->VersionList == 0)
	 continue;

      if ((matcher)(P) == false)
	 continue;

      pkgDepCache::StateCache &state = (*DepCache)[P];
      if (insertCurrentVer == true)
      {
	 if (P->CurrentVer != 0)
	    vci->FromPackage(vci, CacheFile, P, APT::CacheSetHelper::INSTALLED, helper);
      }
      else if (insertUpgradable == true)
      {
	 if(P.CurrentVer() && state.Upgradable())
	    vci->FromPackage(vci, CacheFile, P, APT::CacheSetHelper::CANDIDATE, helper);
      }
      else if (insertManualInstalled == true)
      {
	 if (P.CurrentVer() &&
	       ((*DepCache)[P].Flags & pkgCache::Flag::Auto) == false)
	    vci->FromPackage(vci, CacheFile, P, APT::CacheSetHelper::CANDIDATE, helper);
      }
      else
      {
         if (vci->FromPackage(vci, CacheFile, P, APT::CacheSetHelper::CANDIDATE, helper) == false)
	 {
	    // no candidate, this may happen for packages in
	    // dpkg "deinstall ok config-file" state - we pick the first ver
	    // (which should be the only one)
	    vci->insert(P.VersionList());
	 }
      }
   }
   if (progress != NULL)
      progress->Done();
   return true;
}
									/*}}}*/

// CacheSetHelper saving virtual packages				/*{{{*/
pkgCache::VerIterator CacheSetHelperVirtuals::canNotGetVersion(
      enum CacheSetHelper::VerSelector const select,
      pkgCacheFile &Cache,
      pkgCache::PkgIterator const &Pkg)
{
   if (select == NEWEST || select == CANDIDATE || select == ALL)
      virtualPkgs.insert(Pkg);
   return CacheSetHelper::canNotGetVersion(select, Cache, Pkg);
}
void CacheSetHelperVirtuals::canNotFindVersion(
      enum CacheSetHelper::VerSelector const select,
      APT::VersionContainerInterface * vci,
      pkgCacheFile &Cache,
      pkgCache::PkgIterator const &Pkg)
{
   if (select == NEWEST || select == CANDIDATE || select == ALL)
      virtualPkgs.insert(Pkg);
   return CacheSetHelper::canNotFindVersion(select, vci, Cache, Pkg);
}
CacheSetHelperVirtuals::CacheSetHelperVirtuals(bool const ShowErrors, GlobalError::MsgType const &ErrorType) :
   CacheSetHelper{ShowErrors, ErrorType}
{}
									/*}}}*/

// CacheSetHelperAPTGet - responsible for message telling from the CacheSets/*{{{*/
CacheSetHelperAPTGet::CacheSetHelperAPTGet(std::ostream &out) :
   APT::CacheSetHelper{true}, out(out)
{
   explicitlyNamed = true;
}
void CacheSetHelperAPTGet::showTaskSelection(pkgCache::PkgIterator const &Pkg, std::string const &pattern)
{
   ioprintf(out, _("Note, selecting '%s' for task '%s'\n"),
	 Pkg.FullName(true).c_str(), pattern.c_str());
   explicitlyNamed = false;
}
void CacheSetHelperAPTGet::showFnmatchSelection(pkgCache::PkgIterator const &Pkg, std::string const &pattern)
{
   ioprintf(out, _("Note, selecting '%s' for glob '%s'\n"),
	 Pkg.FullName(true).c_str(), pattern.c_str());
   explicitlyNamed = false;
}
void CacheSetHelperAPTGet::showRegExSelection(pkgCache::PkgIterator const &Pkg, std::string const &pattern)
{
   ioprintf(out, _("Note, selecting '%s' for regex '%s'\n"),
	 Pkg.FullName(true).c_str(), pattern.c_str());
   explicitlyNamed = false;
}
void CacheSetHelperAPTGet::showSelectedVersion(pkgCache::PkgIterator const &/*Pkg*/, pkgCache::VerIterator const Ver,
      std::string const &ver, bool const /*verIsRel*/)
{
   if (ver == Ver.VerStr())
      return;
   selectedByRelease.push_back(make_pair(Ver, ver));
}
bool CacheSetHelperAPTGet::showVirtualPackageErrors(pkgCacheFile &Cache)
{
   if (virtualPkgs.empty() == true)
      return true;
   for (APT::PackageSet::const_iterator Pkg = virtualPkgs.begin();
	 Pkg != virtualPkgs.end(); ++Pkg) {
      if (Pkg->ProvidesList != 0) {
	 ioprintf(c1out,_("Package %s is a virtual package provided by:\n"),
	       Pkg.FullName(true).c_str());

	 pkgCache::PrvIterator I = Pkg.ProvidesList();
	 unsigned short provider = 0;
	 for (; I.end() == false; ++I) {
	    pkgCache::PkgIterator Pkg = I.OwnerPkg();

	    if (Cache[Pkg].CandidateVerIter(Cache) == I.OwnerVer()) {
	       c1out << "  " << Pkg.FullName(true) << " " << I.OwnerVer().VerStr();
	       if (Cache[Pkg].Install() == true && Cache[Pkg].NewInstall() == false)
		  c1out << _(" [Installed]");
	       c1out << std::endl;
	       ++provider;
	    }
	 }
	 // if we found no candidate which provide this package, show non-candidates
	 if (provider == 0)
	    for (I = Pkg.ProvidesList(); I.end() == false; ++I)
	       c1out << "  " << I.OwnerPkg().FullName(true) << " " << I.OwnerVer().VerStr()
		  << _(" [Not candidate version]") << std::endl;
	 else
	    out << _("You should explicitly select one to install.") << std::endl;
      } else {
	 ioprintf(c1out,
	       _("Package %s is not available, but is referred to by another package.\n"
		  "This may mean that the package is missing, has been obsoleted, or\n"
		  "is only available from another source\n"),Pkg.FullName(true).c_str());

	 std::string List;
	 std::string VersionsList;
	 std::vector<bool> Seen(Cache.GetPkgCache()->Head().PackageCount, false);
	 APT::PackageList pkglist;
	 for (pkgCache::DepIterator Dep = Pkg.RevDependsList();
	       Dep.end() == false; ++Dep) {
	    if (Dep->Type != pkgCache::Dep::Replaces)
	       continue;
	    pkgCache::PkgIterator const DP = Dep.ParentPkg();
	    if (Seen[DP->ID] == true)
	       continue;
	    Seen[DP->ID] = true;
	    pkglist.insert(DP);
	 }
	 ShowList(c1out, _("However the following packages replace it:"), pkglist,
	       &AlwaysTrue, &PrettyFullName, &EmptyString);
      }
      c1out << std::endl;
   }
   return false;
}
pkgCache::VerIterator CacheSetHelperAPTGet::canNotFindCandidateVer(pkgCacheFile &Cache, pkgCache::PkgIterator const &Pkg)
{
   APT::VersionSet const verset = tryVirtualPackage(Cache, Pkg, CacheSetHelper::CANDIDATE);
   if (verset.empty() == false)
      return *(verset.begin());
   else if (ShowError == true) {
      _error->Error(_("Package '%s' has no installation candidate"),Pkg.FullName(true).c_str());
      virtualPkgs.insert(Pkg);
   }
   return pkgCache::VerIterator(Cache, 0);
}
pkgCache::VerIterator CacheSetHelperAPTGet::canNotFindNewestVer(pkgCacheFile &Cache, pkgCache::PkgIterator const &Pkg)
{
   if (Pkg->ProvidesList != 0)
   {
      APT::VersionSet const verset = tryVirtualPackage(Cache, Pkg, CacheSetHelper::NEWEST);
      if (verset.empty() == false)
	 return *(verset.begin());
      if (ShowError == true)
	 ioprintf(out, _("Virtual packages like '%s' can't be removed\n"), Pkg.FullName(true).c_str());
   }
   else
   {
      pkgCache::GrpIterator Grp = Pkg.Group();
      pkgCache::PkgIterator P = Grp.PackageList();
      for (; P.end() != true; P = Grp.NextPkg(P))
      {
	 if (P == Pkg)
	    continue;
	 if (P->CurrentVer != 0) {
	    // TRANSLATORS: Note, this is not an interactive question
	    ioprintf(c1out,_("Package '%s' is not installed, so not removed. Did you mean '%s'?\n"),
		  Pkg.FullName(true).c_str(), P.FullName(true).c_str());
	    break;
	 }
      }
      if (P.end() == true)
	 ioprintf(c1out,_("Package '%s' is not installed, so not removed\n"),Pkg.FullName(true).c_str());
   }
   return pkgCache::VerIterator(Cache, 0);
}
APT::VersionSet CacheSetHelperAPTGet::tryVirtualPackage(pkgCacheFile &Cache, pkgCache::PkgIterator const &Pkg,
      CacheSetHelper::VerSelector const select)
{
   /* This is a pure virtual package and there is a single available
      candidate providing it. */
   if (unlikely(Cache[Pkg].CandidateVer != 0) || Pkg->ProvidesList == 0)
      return APT::VersionSet();

   pkgCache::PkgIterator Prov;
   bool found_one = false;
   for (pkgCache::PrvIterator P = Pkg.ProvidesList(); P; ++P) {
      pkgCache::VerIterator const PVer = P.OwnerVer();
      pkgCache::PkgIterator const PPkg = PVer.ParentPkg();

      /* Ignore versions that are not a candidate. */
      if (Cache[PPkg].CandidateVer != PVer)
	 continue;

      if (found_one == false) {
	 Prov = PPkg;
	 found_one = true;
      } else if (PPkg != Prov) {
	 // same group, so it's a foreign package
	 if (PPkg->Group == Prov->Group) {
	    // do we already have the requested arch?
	    if (strcmp(Pkg.Arch(), Prov.Arch()) == 0 ||
		  strcmp(Prov.Arch(), "all") == 0 ||
		  unlikely(strcmp(PPkg.Arch(), Prov.Arch()) == 0)) // packages have only on candidate, but just to be sure
	       continue;
	    // see which architecture we prefer more and switch to it
	    std::vector<std::string> archs = APT::Configuration::getArchitectures();
	    if (std::find(archs.begin(), archs.end(), PPkg.Arch()) < std::find(archs.begin(), archs.end(), Prov.Arch()))
	       Prov = PPkg;
	    continue;
	 }
	 found_one = false; // we found at least two
	 break;
      }
   }

   if (found_one == true) {
      ioprintf(out, _("Note, selecting '%s' instead of '%s'\n"),
	    Prov.FullName(true).c_str(), Pkg.FullName(true).c_str());
      return APT::VersionSet::FromPackage(Cache, Prov, select, *this);
   }
   return APT::VersionSet();
}
									/*}}}*/
Commit	Line	Data
453b82a3 DK	1	#include <config.h>
453b82a3 DK	2
b9179170 MV	3	#include <apt-pkg/cachefile.h>
	4	#include <apt-pkg/pkgcache.h>
	5	#include <apt-pkg/depcache.h>
453b82a3	6	#include <apt-pkg/cacheiterators.h>
6cfadda1	7	#include <apt-pkg/aptconfiguration.h>
453b82a3 DK	8	#include <apt-pkg/configuration.h>
	9	#include <apt-pkg/progress.h>
	10	#include <apt-pkg/policy.h>
6cfadda1	11	#include <apt-pkg/strutl.h>
453b82a3 DK	12
	13	#include <apt-private/private-cacheset.h>
	14
	15	#include <stddef.h>
b9179170	16
453b82a3	17	#include <apti18n.h>
b9179170	18
6cfadda1	19	bool GetLocalitySortedVersionSet(pkgCacheFile &CacheFile, /{{{/
25594bb5 DK	20	APT::VersionContainerInterface * const vci,
25594bb5 DK	21	OpProgress * const progress)
b9179170 MV	22	{
b9179170 MV	23	Matcher null_matcher = Matcher();
25594bb5	24	return GetLocalitySortedVersionSet(CacheFile, vci,
b9179170 MV	25	null_matcher, progress);
b9179170 MV	26	}
25594bb5 DK	27	bool GetLocalitySortedVersionSet(pkgCacheFile &CacheFile,
25594bb5 DK	28	APT::VersionContainerInterface * const vci,
b9179170	29	Matcher &matcher,
25594bb5	30	OpProgress * const progress)
b9179170 MV	31	{
	32	pkgCache *Cache = CacheFile.GetPkgCache();
	33	pkgDepCache *DepCache = CacheFile.GetDepCache();
25594bb5	34	APT::CacheSetHelper helper(false);
b9179170 MV	35
b9179170 MV	36	int Done=0;
25594bb5 DK	37	if (progress != NULL)
	38	progress->SubProgress(Cache->Head().PackageCount, _("Sorting"));
	39
	40	bool const insertCurrentVer = _config->FindB("APT::Cmd::Installed", false);
	41	bool const insertUpgradable = _config->FindB("APT::Cmd::Upgradable", false);
	42	bool const insertManualInstalled = _config->FindB("APT::Cmd::Manual-Installed", false);
	43
b9179170 MV	44	for (pkgCache::PkgIterator P = Cache->PkgBegin(); P.end() == false; ++P)
b9179170 MV	45	{
25594bb5 DK	46	if (progress != NULL)
	47	{
	48	if (Done % 500 == 0)
	49	progress->Progress(Done);
	50	++Done;
	51	}
	52
	53	// exclude virtual pkgs
	54	if (P->VersionList == 0)
	55	continue;
b9179170 MV	56
b9179170 MV	57	if ((matcher)(P) == false)
25594bb5	58	continue;
b9179170	59
b9179170	60	pkgDepCache::StateCache &state = (*DepCache)[P];
25594bb5	61	if (insertCurrentVer == true)
b9179170	62	{
25594bb5	63	if (P->CurrentVer != 0)
fdba4d53	64	vci->FromPackage(vci, CacheFile, P, APT::CacheSetHelper::INSTALLED, helper);
b9179170	65	}
25594bb5	66	else if (insertUpgradable == true)
b9179170	67	{
25594bb5	68	if(P.CurrentVer() && state.Upgradable())
fdba4d53	69	vci->FromPackage(vci, CacheFile, P, APT::CacheSetHelper::CANDIDATE, helper);
b9179170	70	}
25594bb5	71	else if (insertManualInstalled == true)
3bdf7da5	72	{
25594bb5 DK	73	if (P.CurrentVer() &&
25594bb5 DK	74	((*DepCache)[P].Flags & pkgCache::Flag::Auto) == false)
fdba4d53	75	vci->FromPackage(vci, CacheFile, P, APT::CacheSetHelper::CANDIDATE, helper);
3bdf7da5	76	}
25594bb5	77	else
b9179170	78	{
fdba4d53	79	if (vci->FromPackage(vci, CacheFile, P, APT::CacheSetHelper::CANDIDATE, helper) == false)
25594bb5 DK	80	{
	81	// no candidate, this may happen for packages in
	82	// dpkg "deinstall ok config-file" state - we pick the first ver
	83	// (which should be the only one)
	84	vci->insert(P.VersionList());
	85	}
b9179170 MV	86	}
b9179170 MV	87	}
25594bb5 DK	88	if (progress != NULL)
25594bb5 DK	89	progress->Done();
b9179170 MV	90	return true;
b9179170 MV	91	}
6cfadda1 DK	92	/}}}/
	93
	94	// CacheSetHelper saving virtual packages /{{{/
	95	pkgCache::VerIterator CacheSetHelperVirtuals::canNotGetVersion(
	96	enum CacheSetHelper::VerSelector const select,
	97	pkgCacheFile &Cache,
	98	pkgCache::PkgIterator const &Pkg)
	99	{
	100	if (select == NEWEST \|\| select == CANDIDATE \|\| select == ALL)
	101	virtualPkgs.insert(Pkg);
	102	return CacheSetHelper::canNotGetVersion(select, Cache, Pkg);
	103	}
	104	void CacheSetHelperVirtuals::canNotFindVersion(
	105	enum CacheSetHelper::VerSelector const select,
	106	APT::VersionContainerInterface * vci,
	107	pkgCacheFile &Cache,
	108	pkgCache::PkgIterator const &Pkg)
	109	{
	110	if (select == NEWEST \|\| select == CANDIDATE \|\| select == ALL)
	111	virtualPkgs.insert(Pkg);
	112	return CacheSetHelper::canNotFindVersion(select, vci, Cache, Pkg);
	113	}
	114	CacheSetHelperVirtuals::CacheSetHelperVirtuals(bool const ShowErrors, GlobalError::MsgType const &ErrorType) :
	115	CacheSetHelper{ShowErrors, ErrorType}
	116	{}
	117	/}}}/
	118
	119	// CacheSetHelperAPTGet - responsible for message telling from the CacheSets/{{{/
	120	CacheSetHelperAPTGet::CacheSetHelperAPTGet(std::ostream &out) :
3dddcdf2	121	APT::CacheSetHelper{true}, out(out)
6cfadda1 DK	122	{
	123	explicitlyNamed = true;
	124	}
	125	void CacheSetHelperAPTGet::showTaskSelection(pkgCache::PkgIterator const &Pkg, std::string const &pattern)
	126	{
	127	ioprintf(out, _("Note, selecting '%s' for task '%s'\n"),
	128	Pkg.FullName(true).c_str(), pattern.c_str());
	129	explicitlyNamed = false;
	130	}
	131	void CacheSetHelperAPTGet::showFnmatchSelection(pkgCache::PkgIterator const &Pkg, std::string const &pattern)
	132	{
	133	ioprintf(out, _("Note, selecting '%s' for glob '%s'\n"),
	134	Pkg.FullName(true).c_str(), pattern.c_str());
	135	explicitlyNamed = false;
	136	}
	137	void CacheSetHelperAPTGet::showRegExSelection(pkgCache::PkgIterator const &Pkg, std::string const &pattern)
	138	{
	139	ioprintf(out, _("Note, selecting '%s' for regex '%s'\n"),
	140	Pkg.FullName(true).c_str(), pattern.c_str());
	141	explicitlyNamed = false;
	142	}
	143	void CacheSetHelperAPTGet::showSelectedVersion(pkgCache::PkgIterator const &/Pkg/, pkgCache::VerIterator const Ver,
	144	std::string const &ver, bool const /verIsRel/)
	145	{
	146	if (ver == Ver.VerStr())
	147	return;
	148	selectedByRelease.push_back(make_pair(Ver, ver));
	149	}
	150	bool CacheSetHelperAPTGet::showVirtualPackageErrors(pkgCacheFile &Cache)
	151	{
	152	if (virtualPkgs.empty() == true)
	153	return true;
	154	for (APT::PackageSet::const_iterator Pkg = virtualPkgs.begin();
	155	Pkg != virtualPkgs.end(); ++Pkg) {
	156	if (Pkg->ProvidesList != 0) {
	157	ioprintf(c1out,_("Package %s is a virtual package provided by:\n"),
	158	Pkg.FullName(true).c_str());
	159
	160	pkgCache::PrvIterator I = Pkg.ProvidesList();
	161	unsigned short provider = 0;
	162	for (; I.end() == false; ++I) {
	163	pkgCache::PkgIterator Pkg = I.OwnerPkg();
	164
	165	if (Cache[Pkg].CandidateVerIter(Cache) == I.OwnerVer()) {
	166	c1out << " " << Pkg.FullName(true) << " " << I.OwnerVer().VerStr();
	167	if (Cache[Pkg].Install() == true && Cache[Pkg].NewInstall() == false)
	168	c1out << _(" [Installed]");
	169	c1out << std::endl;
	170	++provider;
	171	}
	172	}
	173	// if we found no candidate which provide this package, show non-candidates
	174	if (provider == 0)
	175	for (I = Pkg.ProvidesList(); I.end() == false; ++I)
	176	c1out << " " << I.OwnerPkg().FullName(true) << " " << I.OwnerVer().VerStr()
	177	<< _(" [Not candidate version]") << std::endl;
	178	else
	179	out << _("You should explicitly select one to install.") << std::endl;
	180	} else {
	181	ioprintf(c1out,
	182	_("Package %s is not available, but is referred to by another package.\n"
	183	"This may mean that the package is missing, has been obsoleted, or\n"
	184	"is only available from another source\n"),Pkg.FullName(true).c_str());
	185
186	std::string List;
187	std::string VersionsList;
188	std::vector<bool> Seen(Cache.GetPkgCache()->Head().PackageCount, false);
189	APT::PackageList pkglist;
190	for (pkgCache::DepIterator Dep = Pkg.RevDependsList();
191	Dep.end() == false; ++Dep) {
192	if (Dep->Type != pkgCache::Dep::Replaces)
193	continue;
194	pkgCache::PkgIterator const DP = Dep.ParentPkg();
195	if (Seen[DP->ID] == true)
196	continue;
197	Seen[DP->ID] = true;
198	pkglist.insert(DP);
199	}
200	ShowList(c1out, _("However the following packages replace it:"), pkglist,
201	&AlwaysTrue, &PrettyFullName, &EmptyString);
202	}
203	c1out << std::endl;
204	}
205	return false;
206	}
207	pkgCache::VerIterator CacheSetHelperAPTGet::canNotFindCandidateVer(pkgCacheFile &Cache, pkgCache::PkgIterator const &Pkg)
208	{
209	APT::VersionSet const verset = tryVirtualPackage(Cache, Pkg, CacheSetHelper::CANDIDATE);
210	if (verset.empty() == false)
211	return *(verset.begin());
212	else if (ShowError == true) {
213	_error->Error(_("Package '%s' has no installation candidate"),Pkg.FullName(true).c_str());
214	virtualPkgs.insert(Pkg);
215	}
216	return pkgCache::VerIterator(Cache, 0);
217	}
218	pkgCache::VerIterator CacheSetHelperAPTGet::canNotFindNewestVer(pkgCacheFile &Cache, pkgCache::PkgIterator const &Pkg)
219	{
220	if (Pkg->ProvidesList != 0)
221	{
222	APT::VersionSet const verset = tryVirtualPackage(Cache, Pkg, CacheSetHelper::NEWEST);
223	if (verset.empty() == false)
224	return *(verset.begin());
225	if (ShowError == true)
226	ioprintf(out, _("Virtual packages like '%s' can't be removed\n"), Pkg.FullName(true).c_str());
227	}
228	else
229	{
230	pkgCache::GrpIterator Grp = Pkg.Group();
231	pkgCache::PkgIterator P = Grp.PackageList();
232	for (; P.end() != true; P = Grp.NextPkg(P))
233	{
234	if (P == Pkg)
235	continue;
236	if (P->CurrentVer != 0) {
237	// TRANSLATORS: Note, this is not an interactive question
238	ioprintf(c1out,_("Package '%s' is not installed, so not removed. Did you mean '%s'?\n"),
239	Pkg.FullName(true).c_str(), P.FullName(true).c_str());
240	break;
241	}
242	}
243	if (P.end() == true)
244	ioprintf(c1out,_("Package '%s' is not installed, so not removed\n"),Pkg.FullName(true).c_str());
245	}
246	return pkgCache::VerIterator(Cache, 0);
247	}
248	APT::VersionSet CacheSetHelperAPTGet::tryVirtualPackage(pkgCacheFile &Cache, pkgCache::PkgIterator const &Pkg,
249	CacheSetHelper::VerSelector const select)
250	{
251	/* This is a pure virtual package and there is a single available
252	candidate providing it. */
253	if (unlikely(Cache[Pkg].CandidateVer != 0) \|\| Pkg->ProvidesList == 0)
254	return APT::VersionSet();
255
256	pkgCache::PkgIterator Prov;
257	bool found_one = false;
258	for (pkgCache::PrvIterator P = Pkg.ProvidesList(); P; ++P) {
259	pkgCache::VerIterator const PVer = P.OwnerVer();
260	pkgCache::PkgIterator const PPkg = PVer.ParentPkg();
261
262	/* Ignore versions that are not a candidate. */
263	if (Cache[PPkg].CandidateVer != PVer)
264	continue;
265
266	if (found_one == false) {
267	Prov = PPkg;
268	found_one = true;
269	} else if (PPkg != Prov) {
270	// same group, so it's a foreign package
271	if (PPkg->Group == Prov->Group) {
272	// do we already have the requested arch?
273	if (strcmp(Pkg.Arch(), Prov.Arch()) == 0 \|\|
274	strcmp(Prov.Arch(), "all") == 0 \|\|
275	unlikely(strcmp(PPkg.Arch(), Prov.Arch()) == 0)) // packages have only on candidate, but just to be sure
276	continue;
277	// see which architecture we prefer more and switch to it
278	std::vector<std::string> archs = APT::Configuration::getArchitectures();
279	if (std::find(archs.begin(), archs.end(), PPkg.Arch()) < std::find(archs.begin(), archs.end(), Prov.Arch()))
280	Prov = PPkg;
281	continue;
282	}
283	found_one = false; // we found at least two
284	break;
285	}
286	}
287
288	if (found_one == true) {
289	ioprintf(out, _("Note, selecting '%s' instead of '%s'\n"),
290	Prov.FullName(true).c_str(), Pkg.FullName(true).c_str());
291	return APT::VersionSet::FromPackage(Cache, Prov, select, *this);
292	}
293	return APT::VersionSet();
294	}
295	/}}}/