fix test cases

pipenv/cli/command.py

@@ -466,7 +466,7 @@ def run(state, command, args):
 @option(
     "--db",
     nargs=1,
-    default=lambda: os.environ.get('PIPENV_SAFETY_DB', False),
+    default=lambda: os.environ.get('PIPENV_SAFETY_DB'),
     help="Path to a local PyUp Safety vulnerabilities database."
          " Default: ENV PIPENV_SAFETY_DB or None.",
 )
@@ -500,7 +500,7 @@ def run(state, command, args):
 def check(
     state,
     unused=False,
-    db=False,
+    db=None,
     style=False,
     ignore=None,
     output="default",

pipenv/core.py

@@ -2558,7 +2558,7 @@ def do_check(
     python=False,
     system=False,
     unused=False,
-    db=False,
+    db=None,
     ignore=None,
     output="default",
     key=None,

pipenv/vendor/tomlkit/items.py

@@ -50,7 +50,7 @@ def item(value, _parent=None, _sort_keys=False):
             val[k] = item(v, _parent=val, _sort_keys=_sort_keys)
 
         return val
-    elif isinstance(value, list):
+    elif isinstance(value, (tuple, list)):
         if value and isinstance(value[0], dict):
             a = AoT([])
         else:

tasks/vendoring/patches/vendor/tomlkit-items-fix.patch

@@ -0,0 +1,13 @@
+diff --git a/pipenv/vendor/tomlkit/items.py b/pipenv/vendor/tomlkit/items.py
+index 6617c522..9e746a8c 100644
+--- a/pipenv/vendor/tomlkit/items.py
++++ b/pipenv/vendor/tomlkit/items.py
+@@ -50,7 +50,7 @@ def item(value, _parent=None, _sort_keys=False):
+             val[k] = item(v, _parent=val, _sort_keys=_sort_keys)
+ 
+         return val
+-    elif isinstance(value, list):
++    elif isinstance(value, (tuple, list)):
+         if value and isinstance(value[0], dict):
+             a = AoT([])
+         else: