tell download methods the expected hashes

Now that we have all hashes in the acquire system, pass the info down to
the methods, so that it can use it in the request and/or to precheck the
response.

apt-pkg/acquire-method.cc

@@ -351,6 +351,15 @@ int pkgAcqMethod::Run(bool Single)
 	       Tmp->LastModified = 0;
 	    Tmp->IndexFile = StringToBool(LookupTag(Message,"Index-File"),false);
 	    Tmp->FailIgnore = StringToBool(LookupTag(Message,"Fail-Ignore"),false);
+	    Tmp->ExpectedHashes = HashStringList();
+	    for (char const * const * t = HashString::SupportedHashes(); *t != NULL; ++t)
+	    {
+	       std::string tag = "Expected-";
+	       tag.append(*t);
+	       std::string const hash = LookupTag(Message, tag.c_str());
+	       if (hash.empty() == false)
+		  Tmp->ExpectedHashes.push_back(HashString(*t, hash));
+	    }
 	    Tmp->Next = 0;
 	    
 	    // Append it to the list

apt-pkg/acquire-method.h

@@ -47,6 +47,7 @@ class pkgAcqMethod
       time_t LastModified;
       bool IndexFile;
       bool FailIgnore;
+      HashStringList ExpectedHashes;
    };
    
    struct FetchResult

apt-pkg/acquire-worker.cc

@@ -530,6 +530,9 @@ bool pkgAcquire::Worker::QueueItem(pkgAcquire::Queue::QItem *Item)
    Message.reserve(300);
    Message += "URI: " + Item->URI;
    Message += "\nFilename: " + Item->Owner->DestFile;
+   HashStringList const hsl = Item->Owner->HashSums();
+   for (HashStringList::const_iterator hs = hsl.begin(); hs != hsl.end(); ++hs)
+      Message += "\nExpected-" + hs->HashType() + ": " + hs->HashValue();
    Message += Item->Owner->Custom600Headers();
    Message += "\n\n";