made StdinDataRedirection compatible with modifiers writing to stdout

plumbum/commands/base.py

@@ -547,7 +547,7 @@ def machine(self):
         return self.cmd.machine
 
     def popen(self, args=(), **kwargs):
-        if "stdin" in kwargs and kwargs["stdin"] != PIPE:
+        if kwargs.get("stdin") not in (PIPE, None):
             raise RedirectionError("stdin is already redirected")
         data = self.data
         if isinstance(data, str) and self._get_encoding() is not None:
@@ -558,8 +558,9 @@ def popen(self, args=(), **kwargs):
             f.write(chunk)
             data = data[self.CHUNK_SIZE :]
         f.seek(0)
+        kwargs["stdin"] = f
         # try:
-        return self.cmd.popen(args, stdin=f, **kwargs)
+        return self.cmd.popen(args, **kwargs)
         # finally:
         #    f.close()
 

tests/test_local.py

@@ -639,6 +639,25 @@ def test_tee_race(self, capfd):
             assert result[1] == EXPECT
             assert EXPECT == capfd.readouterr()[0]
 
+    @skip_on_windows
+    @pytest.mark.parametrize(
+        "modifier, expected",
+        [
+            (FG, None),
+            (TF(FG=True), True),
+            (RETCODE(FG=True), 0),
+            (TEE, (0, "meow", "")),
+        ],
+    )
+    def test_redirection_stdin_modifiers_fg(self, modifier, expected, capfd):
+        "StdinDataRedirection compatible with modifiers which write to stdout"
+        from plumbum.cmd import cat
+
+        cmd = cat << "meow"
+
+        assert cmd & modifier == expected
+        assert capfd.readouterr() == ("meow", "")
+
     @skip_on_windows
     def test_logger_pipe(self):
         from plumbum.cmd import bash