implement Fallback-Of for IndexTargets

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

diff --git a/apt-pkg/acquire-item.cc b/apt-pkg/acquire-item.cc
index 959627a01ed2a6111568767e05ff5b388f31ae70..8c45acdddb9c2117dc4461849c9124c4353ade7e 100644 (file)
--- a/apt-pkg/acquire-item.cc
+++ b/apt-pkg/acquire-item.cc
@@ -1196,9 +1196,18 @@ void pkgAcqMetaClearSig::QueueIndexes(bool const verify)                 /*{{{*/
    // at this point the real Items are loaded in the fetcher
    ExpectedAdditionalItems = 0;
 
+   std::set<std::string> targetsSeen;
    bool const metaBaseSupportsByHash = TransactionManager->MetaIndexParser->GetSupportsAcquireByHash();
-   for (auto Target : TransactionManager->MetaIndexParser->GetIndexTargets())
+   for (auto &Target: TransactionManager->MetaIndexParser->GetIndexTargets())
    {
+      // if we have seen a target which is created-by a target this one here is declared a
+      // fallback to, we skip acquiring the fallback (but we make sure we clean up)
+      if (targetsSeen.find(Target.Option(IndexTarget::FALLBACK_OF)) != targetsSeen.end())
+      {
+        targetsSeen.emplace(Target.Option(IndexTarget::CREATED_BY));
+        new CleanupItem(Owner, TransactionManager, Target);
+        continue;
+      }
       // all is an implementation detail. Users shouldn't use this as arch
       // We need this support trickery here as e.g. Debian has binary-all files already,
       // but arch:all packages are still in the arch:any files, so we would waste precious
@@ -1267,6 +1276,7 @@ void pkgAcqMetaClearSig::QueueIndexes(bool const verify)                  /*{{{*/
               else if (hashes.FileSize() == 0)
               {
                  new CleanupItem(Owner, TransactionManager, Target);
+                 targetsSeen.emplace(Target.Option(IndexTarget::CREATED_BY));
                  continue;
               }
            }
@@ -1327,6 +1337,7 @@ void pkgAcqMetaClearSig::QueueIndexes(bool const verify)                  /*{{{*/
            std::string const idxfilename = GetFinalFileNameFromURI(GetDiffIndexURI(Target));
            if (FileExists(idxfilename))
               new NoActionItem(Owner, Target, idxfilename);
+           targetsSeen.emplace(Target.Option(IndexTarget::CREATED_BY));
            continue;
         }
 
@@ -1348,6 +1359,7 @@ void pkgAcqMetaClearSig::QueueIndexes(bool const verify)                  /*{{{*/
       }
 
       // Queue the Index file (Packages, Sources, Translation-$foo, …)
+      targetsSeen.emplace(Target.Option(IndexTarget::CREATED_BY));
       if (trypdiff)
          new pkgAcqDiffIndex(Owner, TransactionManager, Target);
       else