--- apt-0.5.15lorg3.94pt/cmdline/apt-get.cc.builddep	2010-12-06 18:04:56.403266834 +0100
+++ apt-0.5.15lorg3.94pt/cmdline/apt-get.cc	2010-12-06 18:06:29.030808359 +0100
@@ -2354,6 +2354,74 @@ bool DoBuildDep(CommandLine &CmdL)
                }
             }
 
+	if ((*Cache)[Pkg].CandidateVer == 0 && Pkg->ProvidesList != 0 &&
+	    (Pkg.ProvidesList()->NextProvides == 0 ||
+	     _config->FindB("APT::Install::Virtual", false)))
+	{
+	   pkgCache::PkgIterator Tmp = Pkg.ProvidesList().OwnerPkg();
+	   if ((*D).Version[0] != '\0')
+	      {
+	     // Versioned dependency
+     		pkgCache::PrvIterator PrvItr = Pkg.ProvidesList();
+     		for (; !PrvItr.end(); ++PrvItr)
+     		{
+	       if (Cache->VS().CheckDep(PrvItr.ProvideVersion(),(*D).Op,(*D).Version.c_str()) == true)
+     		      {
+     			Tmp = PrvItr.OwnerPkg();
+     			    break;
+     		  }
+     		}
+     		    if (PrvItr.end())
+     		    {
+     					  return _error->Error(_("%s dependency for %s cannot be satisfied "
+     						  "because no available versions of package %s "
+     						  "can satisfy version requirements"),
+     						Last->BuildDepType((*D).Type),Src.c_str(),
+     						(*D).Package.c_str());
+     		    }
+	      }
+
+	   // CNC:2003-11-21 - Check if the current candidate is really
+	   //		       providing that dependency
+	   ioprintf(c1out,_("Selecting %s for '%s'\n"),
+     		   Tmp.Name(),Pkg.Name());
+	   pkgCache::VerIterator Ver = (*Cache)[Tmp].CandidateVerIter(Cache);
+	   pkgCache::PrvIterator Prv = Ver.ProvidesList();
+	   bool Found = false;
+	   for (; Prv.end() == false; Prv++) {
+	     if (strcmp(Prv.Name(), Pkg.Name()) == 0) {
+     		Found = true;
+     		break;
+	     }
+	   }
+	   if (Found == false) {
+	     // The current candidate doesn't provide the needed dependency.
+	     // Look for one that does.
+	     Ver = Tmp.VersionList();
+	     for (; Ver.end() == false; Ver++) {
+     		Prv = Ver.ProvidesList();
+     		Found = false;
+     		for (; Prv.end() == false; Prv++) {
+     		   if (strcmp(Prv.Name(), Pkg.Name()) == 0) {
+     		      Found = true;
+     		      break;
+     		   }
+     		}
+     		if (Found) {
+     		   (*Cache).SetCandidateVersion(Ver);
+     		   break;
+     		}
+	     }
+	     if (Found == false) {
+     		ioprintf(c1out,_("Internal error. Package %s doesn't provide %s\n"),Tmp.Name(),Pkg.Name());
+     		return false;
+	     }
+	   }
+	   Pkg = Tmp;
+	}
+	else
+	{
+
             // Get installed version and version we are going to install
 	    pkgCache::VerIterator IV = installed ? (*Cache)[Prv.OwnerPkg()].InstVerIter(*Cache):
                                    (*Cache)[Pkg].InstVerIter(*Cache);
@@ -2420,6 +2488,7 @@ bool DoBuildDep(CommandLine &CmdL)
                                        Pkg.Name());
                }
             }
+	}
 
 
             if (_config->FindB("Debug::BuildDeps",false) == true)