From 8246e539bcd55c34a655849c4d53da75453f44b3 Mon Sep 17 00:00:00 2001
From: Kovid Goyal <kovid@kovidgoyal.net>
Date: Tue, 9 May 2017 23:05:58 +0530
Subject: [PATCH] Retry sw download on appveyor

---
 setup/win-ci.py | 14 ++++++++++++--
 1 file changed, 12 insertions(+), 2 deletions(-)

diff --git a/setup/win-ci.py b/setup/win-ci.py
index 32f640025b..690bc38f43 100644
--- a/setup/win-ci.py
+++ b/setup/win-ci.py
@@ -9,6 +9,7 @@ import os
 import subprocess
 import sys
 import tarfile
+import time
 
 try:
     import _winreg as winreg
@@ -159,13 +160,22 @@ def printf(*args, **kw):
     sys.stdout.flush()
 
 
+def download_file(url):
+    for i in range(5):
+        try:
+            printf('Downloading', url)
+            return subprocess.check_output(['curl.exe', '-fsSL', url])
+        except subprocess.CalledProcessError:
+            time.sleep(1)
+    raise SystemExit('Failed to download: {}'.format(url))
+
+
 def sw():
     sw = os.environ['SW']
     os.makedirs(sw)
     os.chdir(sw)
     url = 'https://download.calibre-ebook.com/travis/win-64.tar.xz'
-    printf('Downloading', url)
-    tarball = subprocess.check_output(['curl.exe', '-fsSL', url])
+    tarball = download_file(url)
     with tarfile.open(fileobj=io.BytesIO(tarball)) as tf:
         tf.extractall()
     printf('Download complete')