From 9b2a73f9abb34e6bd207570a14121fb20a43735a Mon Sep 17 00:00:00 2001
From: Simon Frei <freisim93@gmail.com>
Date: Wed, 10 Apr 2019 16:22:23 +0200
Subject: [PATCH] lib/model: Pause pull for at least as long as failed pull
 took (fixes #5641) (#5643)

---
 lib/model/folder.go | 38 +++++++++++++++++++-------------------
 1 file changed, 19 insertions(+), 19 deletions(-)

diff --git a/lib/model/folder.go b/lib/model/folder.go
index 0a155041c..087286127 100644
--- a/lib/model/folder.go
+++ b/lib/model/folder.go
@@ -132,6 +132,23 @@ func (f *folder) Serve() {
 
 	initialCompleted := f.initialScanFinished
 
+	pull := func() {
+		startTime := time.Now()
+		if f.puller.pull() {
+			// We're good. Don't schedule another pull and reset
+			// the pause interval.
+			pause = f.basePause()
+			return
+		}
+		// Pulling failed, try again later.
+		delay := pause + time.Since(startTime)
+		l.Infof("Folder %v isn't making sync progress - retrying in %v.", f.Description(), delay)
+		pullFailTimer.Reset(delay)
+		if pause < 60*f.basePause() {
+			pause *= 2
+		}
+	}
+
 	for {
 		select {
 		case <-f.ctx.Done():
@@ -143,27 +160,10 @@ func (f *folder) Serve() {
 			case <-pullFailTimer.C:
 			default:
 			}
-
-			if !f.puller.pull() {
-				// Pulling failed, try again later.
-				pullFailTimer.Reset(pause)
-			}
+			pull()
 
 		case <-pullFailTimer.C:
-			if f.puller.pull() {
-				// We're good. Don't schedule another fail pull and reset
-				// the pause interval.
-				pause = f.basePause()
-				continue
-			}
-
-			// Pulling failed, try again later.
-			l.Infof("Folder %v isn't making sync progress - retrying in %v.", f.Description(), pause)
-			pullFailTimer.Reset(pause)
-			// Back off from retrying to pull with an upper limit.
-			if pause < 60*f.basePause() {
-				pause *= 2
-			}
+			pull()
 
 		case <-initialCompleted:
 			// Initial scan has completed, we should do a pull