diff --git a/core/datatypes.py b/core/datatypes.py
index 6b4abcc..b323990 100755
--- a/core/datatypes.py
+++ b/core/datatypes.py
@@ -1270,7 +1270,12 @@ def execute(self, args: list[Value], kwargs: dict[str, Value]) -> RTResult[Value
         if res.should_return() and res.func_return_value is None:
             return res
 
-        ret_value = (value if self.should_auto_return else None) or res.func_return_value or Null.null()
+        if self.should_auto_return:
+            ret_value = value
+        else:
+            ret_value = res.func_return_value
+        if ret_value is None:
+            ret_value = Null.null()
         return res.success(ret_value)
 
     def copy(self) -> Function:
diff --git a/core/parser.py b/core/parser.py
index d2b76d7..a9b5b69 100755
--- a/core/parser.py
+++ b/core/parser.py
@@ -1586,8 +1586,8 @@ def failure(self, error: Error) -> RTResult[T]:
     def should_return(self) -> bool:
         # Note: this will allow you to continue and break outside the current function
         return bool(
-            self.error
-            or self.func_return_value
+            self.error is not None
+            or self.func_return_value is not None
             or self.loop_should_continue
             or self.loop_should_break
             or self.should_exit
diff --git a/radon.py b/radon.py
index db5ae2c..379dd5d 100755
--- a/radon.py
+++ b/radon.py
@@ -133,7 +133,8 @@ def main(argv: list[str]) -> None:
     base_core.global_symbol_table.set("argv", base_core.radonify(argv, pos, pos, Context("<global>")))
     if source_file is not None:
         head, tail = os.path.split(source_file)
-        os.chdir(head)
+        if head != "":
+            os.chdir(head)
         with open(tail, "r") as f:
             source = f.read()
         (result, error, should_exit) = base_core.run(source_file, source)