Ensure searches with a leading slash are treated as queries

A user reported a bug where searches with a leading slash (in this case:
"/e/OS apps" were interpreted as a Google specific link when clicking
the next page of results.

This was due to the behavior that Google's search results exhibit, where
internal links for pages like support.google.com are delivered with
params like "?q=/support" rather than a direct link. This fixes that
scenario by checking the "q" param value against the user's original
query to ensure they don't match before assuming that the result is
intended as a redirect.

Fixes #776

app/filter.py

@@ -89,11 +89,13 @@ class Filter:
             config: Config,
             root_url='',
             page_url='',
+            query='',
             mobile=False) -> None:
         self.config = config
         self.mobile = mobile
         self.user_key = user_key
         self.page_url = page_url
+        self.query = query
         self.main_divs = ResultSet('')
         self._elements = 0
         self._av = set()
@@ -429,7 +431,7 @@ class Filter:
         result_link = urlparse.urlparse(href)
         q = extract_q(result_link.query, href)
 
-        if q.startswith('/'):
+        if q.startswith('/') and q not in self.query:
             # Internal google links (i.e. mail, maps, etc) should still
             # be forwarded to Google
             link['href'] = 'https://google.com' + q

app/utils/search.py

@@ -118,7 +118,8 @@ class Search:
         content_filter = Filter(self.session_key,
                                 root_url=self.request.url_root,
                                 mobile=mobile,
-                                config=self.config)
+                                config=self.config,
+                                query=self.query)
         full_query = gen_query(self.query,
                                self.request_params,
                                self.config)

test/test_results.py

@@ -122,3 +122,23 @@ def test_recent_results(client):
                 assert (current_date - date).days <= (num_days + 5)
             except ParserError:
                 pass
+
+
+def test_leading_slash_search(client):
+    # Ensure searches with a leading slash are interpreted
+    # correctly as queries and not endpoints
+    q = '/test'
+    rv = client.get(f'/{Endpoint.search}?q={q}')
+    assert rv._status_code == 200
+
+    soup = Filter(
+        user_key=generate_user_key(),
+        config=Config(**demo_config),
+        query=q
+    ).clean(BeautifulSoup(rv.data, 'html.parser'))
+
+    for link in soup.find_all('a', href=True):
+        if 'start=' not in link['href']:
+            continue
+
+        assert link['href'].startswith(f'{Endpoint.search}')