From 9ad63287eb5ba93b80b9e37619924d3d43e550a7 Mon Sep 17 00:00:00 2001
From: Felix Yan <felixonmars@archlinux.org>
Date: Tue, 9 Jan 2018 11:32:50 +0800
Subject: [PATCH] Handle exception for no-tag situation

Before:
```
[E 01-09 11:26:03.736 core:132] unexpected error happened with dnscrypt-proxy
    Traceback (most recent call last):
      File "/usr/lib/python3.6/site-packages/nvchecker/core.py", line 128, in future_done
        version = fu.result()
      File "/usr/lib/python3.6/site-packages/nvchecker/get_version.py", line 43, in get_version
        version = await func(name, conf)
      File "/usr/lib/python3.6/site-packages/nvchecker/source/github.py", line 43, in get_version
        version = data[-1]
    IndexError: list index out of range
```

After:
```
[E 01-09 11:32:35.308 github:50] dnscrypt-proxy: No tag found in upstream repository.
```
---
 nvchecker/source/github.py | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/nvchecker/source/github.py b/nvchecker/source/github.py
index 526576b..77c2a69 100644
--- a/nvchecker/source/github.py
+++ b/nvchecker/source/github.py
@@ -2,6 +2,7 @@
 # Copyright (c) 2013-2017 lilydjwg <lilydjwg@gmail.com>, et al.
 
 import os
+import logging
 
 from . import session
 from ..sortversion import sort_version_keys
@@ -10,6 +11,8 @@ GITHUB_URL = 'https://api.github.com/repos/%s/commits?sha=%s'
 GITHUB_LATEST_RELEASE = 'https://api.github.com/repos/%s/releases/latest'
 GITHUB_MAX_TAG = 'https://api.github.com/repos/%s/tags'
 
+logger = logging.getLogger(__name__)
+
 async def get_version(name, conf):
   repo = conf.get('github')
   br = conf.get('branch', 'master')
@@ -36,10 +39,16 @@ async def get_version(name, conf):
   async with session.get(url, headers=headers, **kwargs) as res:
     data = await res.json()
   if use_latest_release:
+    if 'tag_name' not in data:
+      logger.error('%s: No tag found in upstream repository.', name)
+      return
     version = data['tag_name']
   elif use_max_tag:
     data = [tag["name"] for tag in data if tag["name"] not in ignored_tags]
     data.sort(key=sort_version_key)
+    if not len(data):
+      logger.error('%s: No tag found in upstream repository.', name)
+      return
     version = data[-1]
   else:
     # YYYYMMDD.HHMMSS