Bug #807012 also involves package dependencies :/.

[apt.git] / apt-pkg / acquire-worker.cc

diff --git a/apt-pkg/acquire-worker.cc b/apt-pkg/acquire-worker.cc
index 176772dde47d5c93a75bc0449390cbf7f56cd201..7d6e6f79c2e5b95d520fe7bec49b2219eec6c4aa 100644 (file)
--- a/apt-pkg/acquire-worker.cc
+++ b/apt-pkg/acquire-worker.cc
@@ -23,6 +23,7 @@
 #include <apt-pkg/strutl.h>
 #include <apt-pkg/hashes.h>
 
 #include <apt-pkg/strutl.h>
 #include <apt-pkg/hashes.h>
 

+#include <algorithm>

 #include <string>
 #include <vector>
 #include <iostream>
 #include <string>
 #include <vector>
 #include <iostream>


@@ -41,29 +42,16 @@
 using namespace std;
 
 // Worker::Worker - Constructor for Queue startup                      /*{{{*/
 using namespace std;
 
 // Worker::Worker - Constructor for Queue startup                      /*{{{*/

-// ---------------------------------------------------------------------
-/* */
-pkgAcquire::Worker::Worker(Queue *Q,MethodConfig *Cnf,
-                          pkgAcquireStatus *log) : d(NULL), Log(log)
+pkgAcquire::Worker::Worker(Queue *Q, MethodConfig *Cnf, pkgAcquireStatus *log) :
+   d(NULL), OwnerQ(Q), Log(log), Config(Cnf), Access(Cnf->Access),
+   CurrentItem(nullptr), CurrentSize(0), TotalSize(0)

 {
 {

-   OwnerQ = Q;
-   Config = Cnf;
-   Access = Cnf->Access;
-   CurrentItem = 0;
-   TotalSize = 0;
-   CurrentSize = 0;
-

    Construct();
 }
                                                                        /*}}}*/
 // Worker::Worker - Constructor for method config startup              /*{{{*/
    Construct();
 }
                                                                        /*}}}*/
 // Worker::Worker - Constructor for method config startup              /*{{{*/

-// ---------------------------------------------------------------------
-/* */
-pkgAcquire::Worker::Worker(MethodConfig *Cnf) : d(NULL), OwnerQ(NULL), Config(Cnf),
-                                               Access(Cnf->Access), CurrentItem(NULL),
-                                               CurrentSize(0), TotalSize(0)
+pkgAcquire::Worker::Worker(MethodConfig *Cnf) : Worker(nullptr, Cnf, nullptr)

 {
 {

-   Construct();

 }
                                                                        /*}}}*/
 // Worker::Construct - Constructor helper                              /*{{{*/
 }
                                                                        /*}}}*/
 // Worker::Construct - Constructor helper                              /*{{{*/


@@ -105,17 +93,38 @@ pkgAcquire::Worker::~Worker()
 bool pkgAcquire::Worker::Start()
 {
    // Get the method path
 bool pkgAcquire::Worker::Start()
 {
    // Get the method path

-   string Method = _config->FindDir("Dir::Bin::Methods") + Access;
+   constexpr char const * const methodsDir = "Dir::Bin::Methods";
+   std::string const confItem = std::string(methodsDir) + "::" + Access;
+   std::string Method;
+   if (_config->Exists(confItem))
+        Method = _config->FindFile(confItem.c_str());
+   else
+        Method = _config->FindDir(methodsDir) + Access;

    if (FileExists(Method) == false)
    {
    if (FileExists(Method) == false)
    {

+      if (flNotDir(Method) == "false")
+      {
+        _error->Error(_("The method '%s' is explicitly disabled via configuration."), Access.c_str());
+        if (Access == "http" || Access == "https")
+           _error->Notice(_("If you meant to use Tor remember to use %s instead of %s."), ("tor+" + Access).c_str(), Access.c_str());
+        return false;
+      }

       _error->Error(_("The method driver %s could not be found."),Method.c_str());
       _error->Error(_("The method driver %s could not be found."),Method.c_str());

-      if (Access == "https")
-        _error->Notice(_("Is the package %s installed?"), "apt-transport-https");
+      std::string const A(Access.cbegin(), std::find(Access.cbegin(), Access.cend(), '+'));
+      std::string pkg;
+      strprintf(pkg, "apt-transport-%s", A.c_str());
+      _error->Notice(_("Is the package %s installed?"), pkg.c_str());

       return false;
    }
       return false;
    }

+   std::string const Calling = _config->FindDir(methodsDir) + Access;

 
    if (Debug == true)
 
    if (Debug == true)

-      clog << "Starting method '" << Method << '\'' << endl;
+   {
+      std::clog << "Starting method '" << Calling << "'";
+      if (Calling != Method)
+        std::clog << " ( via " << Method << " )";
+      std::clog << endl;
+   }

 
    // Create the pipes
    int Pipes[4] = {-1,-1,-1,-1};
 
    // Create the pipes
    int Pipes[4] = {-1,-1,-1,-1};


@@ -140,11 +149,9 @@ bool pkgAcquire::Worker::Start()
       SetCloseExec(STDIN_FILENO,false);
       SetCloseExec(STDERR_FILENO,false);
 
       SetCloseExec(STDIN_FILENO,false);
       SetCloseExec(STDERR_FILENO,false);
 

-      const char *Args[2];
-      Args[0] = Method.c_str();
-      Args[1] = 0;
-      execv(Args[0],(char **)Args);
-      cerr << "Failed to exec method " << Args[0] << endl;
+      const char * const Args[] = { Calling.c_str(), nullptr };
+      execv(Method.c_str() ,const_cast<char **>(Args));
+      std::cerr << "Failed to exec method " << Calling << " ( via " << Method << ")" << endl;

       _exit(100);
    }
 
       _exit(100);
    }
 


@@ -184,6 +191,25 @@ bool pkgAcquire::Worker::ReadMessages()
 // ---------------------------------------------------------------------
 /* This takes the messages from the message queue and runs them through
    the parsers in order. */
 // ---------------------------------------------------------------------
 /* This takes the messages from the message queue and runs them through
    the parsers in order. */

+enum class APT_HIDDEN MessageType {
+   CAPABILITIES = 100,
+   LOG = 101,
+   STATUS = 102,
+   REDIRECT = 103,
+   WARNING = 104,
+   URI_START = 200,
+   URI_DONE = 201,
+   URI_FAILURE = 400,
+   GENERAL_FAILURE = 401,
+   MEDIA_CHANGE = 403
+};
+static bool isDoomedItem(pkgAcquire::Item const * const Itm)
+{
+   auto const TransItm = dynamic_cast<pkgAcqTransactionItem const * const>(Itm);
+   if (TransItm == nullptr)
+      return false;
+   return TransItm->TransactionManager->State != pkgAcqTransactionItem::TransactionStarted;
+}

 bool pkgAcquire::Worker::RunMessages()
 {
    while (MessageQueue.empty() == false)
 bool pkgAcquire::Worker::RunMessages()
 {
    while (MessageQueue.empty() == false)


@@ -196,7 +222,7 @@ bool pkgAcquire::Worker::RunMessages()
 
       // Fetch the message number
       char *End;
 
       // Fetch the message number
       char *End;

-      int Number = strtol(Message.c_str(),&End,10);
+      MessageType const Number = static_cast<MessageType>(strtoul(Message.c_str(),&End,10));

       if (End == Message.c_str())
         return _error->Error("Invalid message from method %s: %s",Access.c_str(),Message.c_str());
 
       if (End == Message.c_str())
         return _error->Error("Invalid message from method %s: %s",Access.c_str(),Message.c_str());
 


@@ -222,27 +248,23 @@ bool pkgAcquire::Worker::RunMessages()
       // Determine the message number and dispatch
       switch (Number)
       {
       // Determine the message number and dispatch
       switch (Number)
       {

-        // 100 Capabilities
-        case 100:
+        case MessageType::CAPABILITIES:

         if (Capabilities(Message) == false)
            return _error->Error("Unable to process Capabilities message from %s",Access.c_str());
         break;
 
         if (Capabilities(Message) == false)
            return _error->Error("Unable to process Capabilities message from %s",Access.c_str());
         break;
 

-        // 101 Log
-        case 101:
+        case MessageType::LOG:

         if (Debug == true)
            clog << " <- (log) " << LookupTag(Message,"Message") << endl;
         break;
 
         if (Debug == true)
            clog << " <- (log) " << LookupTag(Message,"Message") << endl;
         break;
 

-        // 102 Status
-        case 102:
+        case MessageType::STATUS:

         Status = LookupTag(Message,"Message");
         break;
 
         Status = LookupTag(Message,"Message");
         break;
 

-         // 103 Redirect
-         case 103:
+        case MessageType::REDIRECT:

          {
          {

-            if (Itm == 0)
+            if (Itm == nullptr)

             {
                _error->Error("Method gave invalid 103 Redirect message");
                break;
             {
                _error->Error("Method gave invalid 103 Redirect message");
                break;


@@ -254,46 +276,62 @@ bool pkgAcquire::Worker::RunMessages()
            ItemDone();
 
            // Change the status so that it can be dequeued
            ItemDone();
 
            // Change the status so that it can be dequeued

-           for (pkgAcquire::Queue::QItem::owner_iterator O = Itm->Owners.begin(); O != Itm->Owners.end(); ++O)
-              (*O)->Status = pkgAcquire::Item::StatIdle;
+           for (auto const &O: Itm->Owners)
+              O->Status = pkgAcquire::Item::StatIdle;

            // Mark the item as done (taking care of all queues)
            // and then put it in the main queue again
            std::vector<Item*> const ItmOwners = Itm->Owners;
            OwnerQ->ItemDone(Itm);
            // Mark the item as done (taking care of all queues)
            // and then put it in the main queue again
            std::vector<Item*> const ItmOwners = Itm->Owners;
            OwnerQ->ItemDone(Itm);

-           Itm = NULL;
-           for (pkgAcquire::Queue::QItem::owner_iterator O = ItmOwners.begin(); O != ItmOwners.end(); ++O)
+           Itm = nullptr;
+           for (auto const &Owner: ItmOwners)

            {
            {

-              pkgAcquire::Item *Owner = *O;

               pkgAcquire::ItemDesc &desc = Owner->GetItemDesc();
               pkgAcquire::ItemDesc &desc = Owner->GetItemDesc();

+              if (Owner->IsRedirectionLoop(NewURI))
+              {
+                 std::string msg = Message;
+                 msg.append("\nFailReason: RedirectionLoop");
+                 Owner->Failed(msg, Config);
+                 if (Log != nullptr)
+                    Log->Fail(Owner->GetItemDesc());
+                 continue;
+              }
+
+              if (Log != nullptr)
+                 Log->Done(desc);
+

               // if we change site, treat it as a mirror change
               if (URI::SiteOnly(NewURI) != URI::SiteOnly(desc.URI))
               {
               // if we change site, treat it as a mirror change
               if (URI::SiteOnly(NewURI) != URI::SiteOnly(desc.URI))
               {

-                 std::string const OldSite = desc.Description.substr(0, desc.Description.find(" "));
-                 if (likely(APT::String::Startswith(desc.URI, OldSite)))
+                 auto const firstSpace = desc.Description.find(" ");
+                 if (firstSpace != std::string::npos)

                  {
                  {

-                    std::string const OldExtra = desc.URI.substr(OldSite.length() + 1);
-                    if (likely(APT::String::Endswith(NewURI, OldExtra)))
+                    std::string const OldSite = desc.Description.substr(0, firstSpace);
+                    if (likely(APT::String::Startswith(desc.URI, OldSite)))

                     {
                     {

-                       std::string const NewSite = NewURI.substr(0, NewURI.length() - OldExtra.length());
-                       Owner->UsedMirror = URI::ArchiveOnly(NewSite);
-                       if (desc.Description.find(" ") != string::npos)
-                          desc.Description.replace(0, desc.Description.find(" "), Owner->UsedMirror);
+                       std::string const OldExtra = desc.URI.substr(OldSite.length() + 1);
+                       if (likely(APT::String::Endswith(NewURI, OldExtra)))
+                       {
+                          std::string const NewSite = NewURI.substr(0, NewURI.length() - OldExtra.length());
+                          Owner->UsedMirror = URI::ArchiveOnly(NewSite);
+                          desc.Description.replace(0, firstSpace, Owner->UsedMirror);
+                       }

                     }
                  }
               }
               desc.URI = NewURI;
                     }
                  }
               }
               desc.URI = NewURI;

-              OwnerQ->Owner->Enqueue(desc);
-
-              if (Log != 0)
-                 Log->Done(desc);
+              if (isDoomedItem(Owner) == false)
+                 OwnerQ->Owner->Enqueue(desc);

            }
             break;
          }
 
            }
             break;
          }
 

-        // 200 URI Start
-        case 200:
+        case MessageType::WARNING:
+           _error->Warning("%s: %s", Itm->Owner->DescURI().c_str(), LookupTag(Message,"Message").c_str());
+           break;
+
+        case MessageType::URI_START:

         {
         {

-           if (Itm == 0)
+           if (Itm == nullptr)

            {
               _error->Error("Method gave invalid 200 URI Start message");
               break;
            {
               _error->Error("Method gave invalid 200 URI Start message");
               break;


@@ -303,26 +341,24 @@ bool pkgAcquire::Worker::RunMessages()
            CurrentSize = 0;
            TotalSize = strtoull(LookupTag(Message,"Size","0").c_str(), NULL, 10);
            ResumePoint = strtoull(LookupTag(Message,"Resume-Point","0").c_str(), NULL, 10);
            CurrentSize = 0;
            TotalSize = strtoull(LookupTag(Message,"Size","0").c_str(), NULL, 10);
            ResumePoint = strtoull(LookupTag(Message,"Resume-Point","0").c_str(), NULL, 10);

-           for (pkgAcquire::Queue::QItem::owner_iterator O = Itm->Owners.begin(); O != Itm->Owners.end(); ++O)
+           for (auto const Owner: Itm->Owners)

            {
            {

-              (*O)->Start(Message, TotalSize);
-
+              Owner->Start(Message, TotalSize);

               // Display update before completion
               // Display update before completion

-              if (Log != 0)
+              if (Log != nullptr)

               {
                  if (Log->MorePulses == true)
               {
                  if (Log->MorePulses == true)

-                    Log->Pulse((*O)->GetOwner());
-                 Log->Fetch((*O)->GetItemDesc());
+                    Log->Pulse(Owner->GetOwner());
+                 Log->Fetch(Owner->GetItemDesc());

               }
            }
 
            break;
         }
 
               }
            }
 
            break;
         }
 

-        // 201 URI Done
-        case 201:
+        case MessageType::URI_DONE:

         {
         {

-           if (Itm == 0)
+           if (Itm == nullptr)

            {
               _error->Error("Method gave invalid 201 URI Done message");
               break;
            {
               _error->Error("Method gave invalid 201 URI Done message");
               break;


@@ -371,9 +407,9 @@ bool pkgAcquire::Worker::RunMessages()
 
            bool const isIMSHit = StringToBool(LookupTag(Message,"IMS-Hit"),false) ||
               StringToBool(LookupTag(Message,"Alt-IMS-Hit"),false);
 
            bool const isIMSHit = StringToBool(LookupTag(Message,"IMS-Hit"),false) ||
               StringToBool(LookupTag(Message,"Alt-IMS-Hit"),false);

-           for (pkgAcquire::Queue::QItem::owner_iterator O = ItmOwners.begin(); O != ItmOwners.end(); ++O)
+           auto const forcedHash = _config->Find("Acquire::ForceHash");
+           for (auto const Owner: ItmOwners)

            {
            {

-              pkgAcquire::Item * const Owner = *O;

               HashStringList const ExpectedHashes = Owner->GetExpectedHashes();
               if(_config->FindB("Debug::pkgAcquire::Auth", false) == true)
               {
               HashStringList const ExpectedHashes = Owner->GetExpectedHashes();
               if(_config->FindB("Debug::pkgAcquire::Auth", false) == true)
               {


@@ -389,9 +425,10 @@ bool pkgAcquire::Worker::RunMessages()
 
               // decide if what we got is what we expected
               bool consideredOkay = false;
 
               // decide if what we got is what we expected
               bool consideredOkay = false;

-              if (ExpectedHashes.usable())
+              if ((forcedHash.empty() && ExpectedHashes.empty() == false) ||
+                    (forcedHash.empty() == false && ExpectedHashes.usable()))

               {
               {

-                 if (ReceivedHashes.usable() == false)
+                 if (ReceivedHashes.empty())

                  {
                     /* IMS-Hits can't be checked here as we will have uncompressed file,
                        but the hashes for the compressed file. What we have was good through
                  {
                     /* IMS-Hits can't be checked here as we will have uncompressed file,
                        but the hashes for the compressed file. What we have was good through


@@ -404,20 +441,20 @@ bool pkgAcquire::Worker::RunMessages()
                     consideredOkay = false;
 
               }
                     consideredOkay = false;
 
               }

-              else if (Owner->HashesRequired() == true)
-                 consideredOkay = false;

               else
               else

-                 consideredOkay = true;
+                 consideredOkay = !Owner->HashesRequired();

 
               if (consideredOkay == true)
                  consideredOkay = Owner->VerifyDone(Message, Config);
               else // hashsum mismatch
                  Owner->Status = pkgAcquire::Item::StatAuthError;
 
 
               if (consideredOkay == true)
                  consideredOkay = Owner->VerifyDone(Message, Config);
               else // hashsum mismatch
                  Owner->Status = pkgAcquire::Item::StatAuthError;
 

+

               if (consideredOkay == true)
               {
               if (consideredOkay == true)
               {

-                 Owner->Done(Message, ReceivedHashes, Config);
-                 if (Log != 0)
+                 if (isDoomedItem(Owner) == false)
+                    Owner->Done(Message, ReceivedHashes, Config);
+                 if (Log != nullptr)

                  {
                     if (isIMSHit)
                        Log->IMSHit(Owner->GetItemDesc());
                  {
                     if (isIMSHit)
                        Log->IMSHit(Owner->GetItemDesc());


@@ -427,19 +464,29 @@ bool pkgAcquire::Worker::RunMessages()
               }
               else
               {
               }
               else
               {

-                 Owner->Failed(Message,Config);
-                 if (Log != 0)
-                    Log->Fail(Owner->GetItemDesc());
+                 auto SavedDesc = Owner->GetItemDesc();
+                 if (isDoomedItem(Owner) == false)
+                 {
+                    if (Message.find("\nFailReason:") == std::string::npos)
+                    {
+                       if (ReceivedHashes != ExpectedHashes)
+                          Message.append("\nFailReason: HashSumMismatch");
+                       else
+                          Message.append("\nFailReason: WeakHashSums");
+                    }
+                    Owner->Failed(Message,Config);
+                 }
+                 if (Log != nullptr)
+                    Log->Fail(SavedDesc);

               }
            }
            ItemDone();
            break;
         }
 
               }
            }
            ItemDone();
            break;
         }
 

-        // 400 URI Failure
-        case 400:
+        case MessageType::URI_FAILURE:

         {
         {

-           if (Itm == 0)
+           if (Itm == nullptr)

            {
               std::string const msg = LookupTag(Message,"Message");
               _error->Error("Method gave invalid 400 URI Failure message: %s", msg.c_str());
            {
               std::string const msg = LookupTag(Message,"Message");
               _error->Error("Method gave invalid 400 URI Failure message: %s", msg.c_str());


@@ -449,40 +496,51 @@ bool pkgAcquire::Worker::RunMessages()
            PrepareFiles("400::URIFailure", Itm);
 
            // Display update before completion
            PrepareFiles("400::URIFailure", Itm);
 
            // Display update before completion

-           if (Log != 0 && Log->MorePulses == true)
+           if (Log != nullptr && Log->MorePulses == true)

               for (pkgAcquire::Queue::QItem::owner_iterator O = Itm->Owners.begin(); O != Itm->Owners.end(); ++O)
                  Log->Pulse((*O)->GetOwner());
 
            std::vector<Item*> const ItmOwners = Itm->Owners;
            OwnerQ->ItemDone(Itm);
               for (pkgAcquire::Queue::QItem::owner_iterator O = Itm->Owners.begin(); O != Itm->Owners.end(); ++O)
                  Log->Pulse((*O)->GetOwner());
 
            std::vector<Item*> const ItmOwners = Itm->Owners;
            OwnerQ->ItemDone(Itm);

-           Itm = NULL;
+           Itm = nullptr;

 
 

-           for (pkgAcquire::Queue::QItem::owner_iterator O = ItmOwners.begin(); O != ItmOwners.end(); ++O)
+           bool errTransient = false, errAuthErr = false;

            {
            {

-              // set some status
-              if(LookupTag(Message,"FailReason") == "Timeout" ||
-                    LookupTag(Message,"FailReason") == "TmpResolveFailure" ||
-                    LookupTag(Message,"FailReason") == "ResolveFailure" ||
-                    LookupTag(Message,"FailReason") == "ConnectionRefused")
-                 (*O)->Status = pkgAcquire::Item::StatTransientNetworkError;
-
-              (*O)->Failed(Message,Config);
+              std::string const failReason = LookupTag(Message, "FailReason");
+              {
+                 auto const reasons = { "Timeout", "ConnectionRefused",
+                    "ConnectionTimedOut", "ResolveFailure", "TmpResolveFailure" };
+                 errTransient = std::find(std::begin(reasons), std::end(reasons), failReason) != std::end(reasons);
+              }
+              if (errTransient == false)
+              {
+                 auto const reasons = { "HashSumMismatch", "WeakHashSums", "MaximumSizeExceeded" };
+                 errAuthErr = std::find(std::begin(reasons), std::end(reasons), failReason) != std::end(reasons);
+              }
+           }

 
 

-              if (Log != 0)
-                 Log->Fail((*O)->GetItemDesc());
+           for (auto const Owner: ItmOwners)
+           {
+              if (errAuthErr && Owner->GetExpectedHashes().empty() == false)
+                 Owner->Status = pkgAcquire::Item::StatAuthError;
+              else if (errTransient)
+                 Owner->Status = pkgAcquire::Item::StatTransientNetworkError;
+              auto SavedDesc = Owner->GetItemDesc();
+              if (isDoomedItem(Owner) == false)
+                 Owner->Failed(Message,Config);
+              if (Log != nullptr)
+                 Log->Fail(SavedDesc);

            }
            ItemDone();
 
            break;
         }
 
            }
            ItemDone();
 
            break;
         }
 

-        // 401 General Failure
-        case 401:
+        case MessageType::GENERAL_FAILURE:

         _error->Error("Method %s General failure: %s",Access.c_str(),LookupTag(Message,"Message").c_str());
         break;
 
         _error->Error("Method %s General failure: %s",Access.c_str(),LookupTag(Message,"Message").c_str());
         break;
 

-        // 403 Media Change
-        case 403:
+        case MessageType::MEDIA_CHANGE:

         MediaChange(Message);
         break;
       }
         MediaChange(Message);
         break;
       }


@@ -603,6 +661,9 @@ bool pkgAcquire::Worker::QueueItem(pkgAcquire::Queue::QItem *Item)
    if (OutFd == -1)
       return false;
 
    if (OutFd == -1)
       return false;
 

+   if (isDoomedItem(Item->Owner))
+      return true;
+

    string Message = "600 URI Acquire\n";
    Message.reserve(300);
    Message += "URI: " + Item->URI;
    string Message = "600 URI Acquire\n";
    Message.reserve(300);
    Message += "URI: " + Item->URI;


@@ -629,9 +690,9 @@ bool pkgAcquire::Worker::QueueItem(pkgAcquire::Queue::QItem *Item)
 
    if (RealFileExists(Item->Owner->DestFile))
    {
 
    if (RealFileExists(Item->Owner->DestFile))
    {

-      std::string SandboxUser = _config->Find("APT::Sandbox::User");
+      std::string const SandboxUser = _config->Find("APT::Sandbox::User");

       ChangeOwnerAndPermissionOfFile("Item::QueueURI", Item->Owner->DestFile.c_str(),
       ChangeOwnerAndPermissionOfFile("Item::QueueURI", Item->Owner->DestFile.c_str(),

-                                     SandboxUser.c_str(), "root", 0600);
+                                     SandboxUser.c_str(), ROOT_GROUP, 0600);

    }
 
    if (Debug == true)
    }
 
    if (Debug == true)


@@ -727,14 +788,14 @@ void pkgAcquire::Worker::PrepareFiles(char const * const caller, pkgAcquire::Que
 {
    if (RealFileExists(Itm->Owner->DestFile))
    {
 {
    if (RealFileExists(Itm->Owner->DestFile))
    {

-      ChangeOwnerAndPermissionOfFile(caller, Itm->Owner->DestFile.c_str(), "root", "root", 0644);
+      ChangeOwnerAndPermissionOfFile(caller, Itm->Owner->DestFile.c_str(), "root", ROOT_GROUP, 0644);

       std::string const filename = Itm->Owner->DestFile;
       for (pkgAcquire::Queue::QItem::owner_iterator O = Itm->Owners.begin(); O != Itm->Owners.end(); ++O)
       {
         pkgAcquire::Item const * const Owner = *O;
       std::string const filename = Itm->Owner->DestFile;
       for (pkgAcquire::Queue::QItem::owner_iterator O = Itm->Owners.begin(); O != Itm->Owners.end(); ++O)
       {
         pkgAcquire::Item const * const Owner = *O;

-        if (Owner->DestFile == filename)
+        if (Owner->DestFile == filename || filename == "/dev/null")

            continue;
            continue;

-        unlink(Owner->DestFile.c_str());
+        RemoveFile("PrepareFiles", Owner->DestFile);

         if (link(filename.c_str(), Owner->DestFile.c_str()) != 0)
         {
            // different mounts can't happen for us as we download to lists/ by default,
         if (link(filename.c_str(), Owner->DestFile.c_str()) != 0)
         {
            // different mounts can't happen for us as we download to lists/ by default,


@@ -749,7 +810,7 @@ void pkgAcquire::Worker::PrepareFiles(char const * const caller, pkgAcquire::Que
    else
    {
       for (pkgAcquire::Queue::QItem::owner_iterator O = Itm->Owners.begin(); O != Itm->Owners.end(); ++O)
    else
    {
       for (pkgAcquire::Queue::QItem::owner_iterator O = Itm->Owners.begin(); O != Itm->Owners.end(); ++O)

-        unlink((*O)->DestFile.c_str());
+        RemoveFile("PrepareFiles", (*O)->DestFile);

    }
 }
                                                                        /*}}}*/
    }
 }
                                                                        /*}}}*/