Bug #268034 --> Mail imported from Mozilla 1.x dumps messages in wrong mailboxes

when migrating mozilla profiles with multiple servers with the same host name, we should make
sure our hostname based diretory is unique.

sr=bienvenu

mail/components/migration/src/nsSeamonkeyProfileMigrator.cpp

@@ -618,6 +618,11 @@ nsresult nsSeamonkeyProfileMigrator::CopyMailFolders(nsVoidArray* aMailServers,
           nsXPIDLCString hostName; 
           serverBranch->GetCharPref("hostname", getter_Copies(hostName));
           targetMailFolder->Append(NS_ConvertASCIItoUCS2(hostName));  
+
+          // we should make sure the host name based directory we are going to migrate 
+          // the accounts into is unique. This protects against the case where the user
+          // has multiple servers with the same host name.
+          targetMailFolder->CreateUnique(nsIFile::DIRECTORY_TYPE, 0777);
         }
 
         rv = RecursiveCopy(sourceMailFolder, targetMailFolder);