Fixed an issue with device monitor when the “send_on_enter” filter didn’t send EOL chars // Resolve #3787

HISTORY.rst

@@ -12,6 +12,7 @@ PlatformIO Core 5
 ~~~~~~~~~~~~~~~~~~
 
 * Fixed a "The command line is too long" issue with a linking process on Windows (`issue #3827 <https://github.com/platformio/platformio-core/issues/3827>`_)
+* Fixed an issue with `device monitor <https://docs.platformio.org/page/core/userguide/device/cmd_monitor.html>`__ when the "send_on_enter" filter didn't send EOL chars (`issue #3787 <https://github.com/platformio/platformio-core/issues/3787>`_)
 
 5.1.0 (2021-01-28)
 ~~~~~~~~~~~~~~~~~~
@@ -50,7 +51,7 @@ PlatformIO Core 5
   - Improved listing of `multicast DNS services <https://docs.platformio.org/page/core/userguide/device/cmd_list.html>`_
   - Fixed a "UnicodeDecodeError: 'utf-8' codec can't decode byte" when using J-Link for firmware uploading on Linux (`issue #3804 <https://github.com/platformio/platformio-core/issues/3804>`_)
   - Fixed an issue with a compiler driver for ".ccls" language server (`issue #3808 <https://github.com/platformio/platformio-core/issues/3808>`_)
-  - Fixed an issue when `pio device monitor --eol <https://docs.platformio.org/en/latest/core/userguide/device/cmd_monitor.html#cmdoption-pio-device-monitor-eol>`__ and "send_on_enter" filter do not work properly (`issue #3787 <https://github.com/platformio/platformio-core/issues/3787>`_)
+  - Fixed an issue when `pio device monitor --eol <https://docs.platformio.org/page/core/userguide/device/cmd_monitor.html#cmdoption-pio-device-monitor-eol>`__ and "send_on_enter" filter do not work properly (`issue #3787 <https://github.com/platformio/platformio-core/issues/3787>`_)
 
 5.0.4 (2020-12-30)
 ~~~~~~~~~~~~~~~~~~

platformio/commands/device/filters/send_on_enter.py

@@ -32,7 +32,7 @@ class SendOnEnter(DeviceMonitorFilter):
     def tx(self, text):
         self._buffer += text
         if self._buffer.endswith(self._eol):
-            text = self._buffer[: len(self._eol) * -1]
+            text = self._buffer
             self._buffer = ""
             return text
         return ""