From 96b1a1c79c4fc64fe2b688c1fed4719bba58d7af Mon Sep 17 00:00:00 2001
From: Ivan Kravets <me@ikravets.com>
Date: Fri, 30 Oct 2020 14:11:27 +0200
Subject: [PATCH] Fixed an issue with a "wrong" timestamp in device monitor
 output using `"time" filter` // Resolve #3712

---
 HISTORY.rst                                |  1 +
 platformio/commands/device/filters/time.py | 13 ++++++++-----
 2 files changed, 9 insertions(+), 5 deletions(-)

diff --git a/HISTORY.rst b/HISTORY.rst
index d239b46e..80d24872 100644
--- a/HISTORY.rst
+++ b/HISTORY.rst
@@ -20,6 +20,7 @@ PlatformIO Core 5
 - Fixed an "AssertionError: ensure_dir_exists" when checking library updates from simultaneous subprocesses (`issue #3677 <https://github.com/platformio/platformio-core/issues/3677>`_)
 - Fixed an issue when `pio package publish <https://docs.platformio.org/page/core/userguide/package/cmd_publish.html>`__ command removes original archive after submitting to the registry (`issue #3716 <https://github.com/platformio/platformio-core/issues/3716>`_)
 - Fixed an issue when multiple `pio lib install <https://docs.platformio.org/page/core/userguide/lib/cmd_install.html>`__ command with the same local library results in duplicates in ``lib_deps`` (`issue #3715 <https://github.com/platformio/platformio-core/issues/3715>`_)
+- Fixed an issue with a "wrong" timestamp in device monitor output using `"time" filter <https://docs.platformio.org/page/core/userguide/device/cmd_monitor.html#filters>`__ (`issue #3712 <https://github.com/platformio/platformio-core/issues/3712>`_)
 
 5.0.1 (2020-09-10)
 ~~~~~~~~~~~~~~~~~~
diff --git a/platformio/commands/device/filters/time.py b/platformio/commands/device/filters/time.py
index 203e6aa9..0c2d8884 100644
--- a/platformio/commands/device/filters/time.py
+++ b/platformio/commands/device/filters/time.py
@@ -22,13 +22,16 @@ class Timestamp(DeviceMonitorFilter):
 
     def __init__(self, *args, **kwargs):
         super(Timestamp, self).__init__(*args, **kwargs)
-        self._first_text_received = False
+        self._line_started = False
 
     def rx(self, text):
-        if self._first_text_received and "\n" not in text:
+        if self._line_started and "\n" not in text:
             return text
         timestamp = datetime.now().strftime("%H:%M:%S.%f")[:-3]
-        if not self._first_text_received:
-            self._first_text_received = True
-            return "%s > %s" % (timestamp, text)
+        if not self._line_started:
+            self._line_started = True
+            text = "%s > %s" % (timestamp, text)
+        if text.endswith("\n"):
+            self._line_started = False
+            return text[:-1].replace("\n", "\n%s > " % timestamp) + "\n"
         return text.replace("\n", "\n%s > " % timestamp)