fix: Fixed glitches on RTS line when no_reset option on Windows

esptool/loader.py

@@ -300,7 +300,17 @@ def __init__(self, port=DEFAULT_PORT, baud=ESP_ROM_BAUD, trace_enabled=False):
 
         if isinstance(port, str):
             try:
-                self._port = serial.serial_for_url(port, exclusive=True)
+                self._port = serial.serial_for_url(
+                    port, exclusive=True, do_not_open=True
+                )
+                if sys.platform == "win32":
+                    # When opening a port on Windows,
+                    # the RTS/DTR (active low) lines
+                    # need to be set to False (pulled high)
+                    # to avoid unwanted chip reset
+                    self._port.rts = False
+                    self._port.dtr = False
+                self._port.open()
             except serial.serialutil.SerialException as e:
                 port_issues = [
                     [  # does not exist error

test/test_esptool.py

@@ -869,9 +869,6 @@ def test_short_flash_to_external_ROM(self):
         self.verify_readback(0, 1024, "images/one_kb.bin", spi_connection=self.conn)
 
 
-@pytest.mark.skipif(
-    os.name == "nt", reason="Temporarily disabled on windows"
-)  # TODO: ESPTOOL-673
 class TestStubReuse(EsptoolTestCase):
     def test_stub_reuse_with_synchronization(self):
         """Keep the flasher stub running and reuse it the next time."""