Add functional test for 'list --no-deps-only' option.

pip/commands/list.py

@@ -183,13 +183,10 @@ class ListCommand(Command):
         ]
 
     def get_nodeps_only(self, packages, options):
-        installed_pkgs = [
-            dist for dist in self.iter_packages_latest_infos(packages, options)
-        ]
         dep_keys = set()
-        for dist in installed_pkgs:
+        for dist in packages:
             dep_keys.update(requirement.key for requirement in dist.requires())
-        return set(pkg for pkg in installed_pkgs if pkg.key not in dep_keys)
+        return set(pkg for pkg in packages if pkg.key not in dep_keys)
 
     def iter_packages_latest_infos(self, packages, options):
         index_urls = [options.index_url] + options.extra_index_urls

tests/functional/test_list.py

@@ -564,6 +564,17 @@ def test_outdated_formats(script, data):
                      'latest_version': '1.1', 'latest_filetype': 'wheel'}]
 
 
+def test_no_deps_only_flag(script, data):
+    script.pip(
+        'install', '-f', data.find_links, '--no-index', 'TopoRequires4'
+    )
+    result = script.pip('list', '--no-deps-only', expect_stderr=True)
+    assert 'TopoRequires4 ' in result.stdout, str(result)
+    assert 'TopoRequires ' not in result.stdout
+    assert 'TopoRequires2 ' not in result.stdout
+    assert 'TopoRequires3 ' not in result.stdout
+
+
 def test_list_freeze(script, data):
     """
     Test freeze formatting of list command