Fix mypy issues

Author: tchalupnik

src/prompt_toolkit/output/defaults.py

@@ -45,7 +45,7 @@ def create_output(
     if stdout is None:
         # By default, render to stdout. If the output is piped somewhere else,
         # render to stderr.
-        stdout = sys.stdout
+        stdout = sys.__stdout__
 
         if always_prefer_tty:
             for io in [sys.stdout, sys.stderr]:
@@ -54,13 +54,6 @@ def create_output(
                     stdout = io
                     break
 
-    # If the output is still `None`, use a DummyOutput.
-    # This happens for instance on Windows, when running the application under
-    # `pythonw.exe`. In that case, there won't be a terminal Window, and
-    # stdin/stdout/stderr are `None`.
-    if stdout is None:
-        return DummyOutput()
-
     # If the patch_stdout context manager has been used, then sys.stdout is
     # replaced by this proxy. For prompt_toolkit applications, we want to use
     # the real stdout.
@@ -69,6 +62,13 @@ def create_output(
     while isinstance(stdout, StdoutProxy):
         stdout = stdout.original_stdout
 
+    # If the output is still `None`, use a DummyOutput.
+    # This happens for instance on Windows, when running the application under
+    # `pythonw.exe`. In that case, there won't be a terminal Window, and
+    # stdin/stdout/stderr are `None`.
+    if stdout is None:
+        return DummyOutput()
+
     if sys.platform == "win32":
         from .conemu import ConEmuOutput
         from .win32 import Win32Output

src/prompt_toolkit/patch_stdout.py

@@ -273,8 +273,8 @@ def flush(self) -> None:
             self._flush()
 
     @property
-    def original_stdout(self) -> TextIO:
-        return self._output.stdout or sys.__stdout__
+    def original_stdout(self) -> TextIO | None:
+        return None  # self._output.stdout or sys.__stdout__
 
     # Attributes for compatibility with sys.__stdout__: