Catch connection error during Tor validation step

Validation of the Tor connection occasionally fails with a
ConnectionError from requests, which was previously uncaught. This is
now handled appropriately (error message shown and connection dropped).

Fixes #532

app/request.py

@@ -274,14 +274,19 @@ class Request:
 
         # Make sure that the tor connection is valid, if enabled
         if self.tor:
-            tor_check = requests.get('https://check.torproject.org/',
-                                     proxies=self.proxies, headers=headers)
-            self.tor_valid = 'Congratulations' in tor_check.text
-
-            if not self.tor_valid:
+            try:
+                tor_check = requests.get('https://check.torproject.org/',
+                                         proxies=self.proxies, headers=headers)
+                self.tor_valid = 'Congratulations' in tor_check.text
+
+                if not self.tor_valid:
+                    raise TorError(
+                        "Tor connection succeeded, but the connection could "
+                        "not be validated by torproject.org",
+                        disable=True)
+            except ConnectionError:
                 raise TorError(
-                    "Tor connection succeeded, but the connection could not "
-                    "be validated by torproject.org",
+                    "Error raised during Tor connection validation",
                     disable=True)
 
         response = requests.get(

app/utils/search.py

@@ -140,10 +140,8 @@ class Search:
             html_soup = content_filter.view_image(html_soup)
 
         # Indicate whether or not a Tor connection is active
-        tor_banner = bsoup('', 'html.parser')
         if g.user_request.tor_valid:
-            tor_banner = bsoup(TOR_BANNER, 'html.parser')
-        html_soup.insert(0, tor_banner)
+            html_soup.insert(0, bsoup(TOR_BANNER, 'html.parser'))
 
         if self.feeling_lucky:
             return get_first_link(html_soup)