Infinite loop fix

Signed-off-by: mark <mark@threatrix.io>

Author: mark

vulnerabilities/package_managers.py

@@ -660,8 +660,12 @@ def fetch(self, pkg: str) -> Iterable[PackageVersion]:
             url = f"https://proxy.golang.org/{escaped_pkg}/@v/list"
             response = get_response(url=url, content_type="text")
             if not response:
-                escaped_pkg = self.trim_go_url_path(escaped_pkg)
+                trimmed_escaped_pkg = self.trim_go_url_path(escaped_pkg)
                 trimmed_pkg = self.trim_go_url_path(trimmed_pkg) or ""
+                if trimmed_escaped_pkg == escaped_pkg:
+                    break
+
+                escaped_pkg = trimmed_escaped_pkg
                 continue
 
             break

vulnerabilities/tests/test_package_managers.py

@@ -300,6 +300,15 @@ def test_fetch(self, mock_fetcher):
         ]
         assert results == expected
 
+    @mock.patch("vulnerabilities.package_managers.get_response")
+    def test_fetch_with_responses_are_none(self, mock_fetcher):
+        # we have many calls made to get_response
+        responses = [None, None, None, None, None]
+        mock_fetcher.side_effect = responses
+
+        results = list(GoproxyVersionAPI().fetch("github.com/FerretDB/FerretDB"))
+        assert results == []
+
 
 class TestNugetVersionAPI:
     expected_versions = [