From 6bf7dc1baf272b37aa2731544f00491402d323ff Mon Sep 17 00:00:00 2001
From: Will Dietz <w@wdtz.org>
Date: Thu, 24 May 2018 16:23:05 -0500
Subject: [PATCH] download: if there are active requests, never sleep for 10s

In some versions/configurations libcurl doesn't handle timeouts
(especially DNS timeouts) in a way that wakes curl_multi_wait.

This doesn't appear to be a problem if using c-ares, FWIW.
---
 src/libstore/download.cc | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/src/libstore/download.cc b/src/libstore/download.cc
index 7a5deed32..29bb56ea1 100644
--- a/src/libstore/download.cc
+++ b/src/libstore/download.cc
@@ -503,10 +503,11 @@ struct CurlDownloader : public Downloader
             extraFDs[0].fd = wakeupPipe.readSide.get();
             extraFDs[0].events = CURL_WAIT_POLLIN;
             extraFDs[0].revents = 0;
+            long maxSleepTimeMs = items.empty() ? 10000 : 100;
             auto sleepTimeMs =
                 nextWakeup != std::chrono::steady_clock::time_point()
                 ? std::max(0, (int) std::chrono::duration_cast<std::chrono::milliseconds>(nextWakeup - std::chrono::steady_clock::now()).count())
-                : 10000;
+                : maxSleepTimeMs;
             vomit("download thread waiting for %d ms", sleepTimeMs);
             mc = curl_multi_wait(curlm, extraFDs, 1, sleepTimeMs, &numfds);
             if (mc != CURLM_OK)