Fix pipfile creation with unnamed project

- Fixes #3260

Signed-off-by: Dan Ryan <dan@danryan.co>

news/3260.bugfix.rst

@@ -0,0 +1 @@
+Fixed an issue which sometimes prevented successful creation of project pipfiles.

pipenv/project.py

@@ -693,6 +693,7 @@ class Project(object):
             ConfigOptionParser, make_option_group, index_group
         )
 
+        name = self.name if self.name is not None else "Pipfile"
         config_parser = ConfigOptionParser(name=self.name)
         config_parser.add_option_group(make_option_group(index_group, config_parser))
         install = config_parser.option_groups[0]

tests/integration/test_install_basic.py

@@ -418,3 +418,11 @@ requests
         )
         c = p.pipenv("install --system")
         assert c.return_code == 0
+
+
+@pytest.mark.install
+def test_install_creates_pipfile(PipenvInstance):
+    with PipenvInstance(chdir=True) as p:
+        c = p.pipenv("install")
+        assert c.return_code == 0
+        assert os.path.isfile(p.pipfile_path)