From 7348653ff4fc4e9b2dc24943aabdb57179b1c75a Mon Sep 17 00:00:00 2001
From: Eelco Dolstra <edolstra@gmail.com>
Date: Tue, 3 Sep 2019 12:51:35 +0200
Subject: Ensure that Callback is called only once

Also, make Callback movable but uncopyable.
---
 src/libstore/download.cc | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

(limited to 'src/libstore/download.cc')

diff --git a/src/libstore/download.cc b/src/libstore/download.cc
index a7d059465b0e..cdf56e09d69a 100644
--- a/src/libstore/download.cc
+++ b/src/libstore/download.cc
@@ -77,13 +77,13 @@ struct CurlDownloader : public Downloader
 
         DownloadItem(CurlDownloader & downloader,
             const DownloadRequest & request,
-            Callback<DownloadResult> callback)
+            Callback<DownloadResult> && callback)
             : downloader(downloader)
             , request(request)
             , act(*logger, lvlTalkative, actDownload,
                 fmt(request.data ? "uploading '%s'" : "downloading '%s'", request.uri),
                 {request.uri}, request.parentAct)
-            , callback(callback)
+            , callback(std::move(callback))
             , finalSink([this](const unsigned char * data, size_t len) {
                 if (this->request.dataCallback) {
                     writtenToSink += len;
@@ -665,7 +665,7 @@ struct CurlDownloader : public Downloader
             return;
         }
 
-        enqueueItem(std::make_shared<DownloadItem>(*this, request, callback));
+        enqueueItem(std::make_shared<DownloadItem>(*this, request, std::move(callback)));
     }
 };
 
-- 
cgit 1.4.1