From 9fa424ea9b70df077d639196193e2eee2443718c Mon Sep 17 00:00:00 2001
From: Ivan Kravets <me@ikravets.com>
Date: Wed, 28 Aug 2019 22:43:34 +0300
Subject: [PATCH] Remove ProjectConfig from cache on saving

---
 HISTORY.rst                  | 2 +-
 platformio/project/config.py | 3 +++
 2 files changed, 4 insertions(+), 1 deletion(-)

diff --git a/HISTORY.rst b/HISTORY.rst
index cc4e0b4a..902cac55 100644
--- a/HISTORY.rst
+++ b/HISTORY.rst
@@ -12,7 +12,7 @@ PlatformIO 4.0
 * Update SCons tool to 3.1.1
 * Remove ProjectConfig cache when "platformio.ini" was modified outside
 * Fixed an issue with PIO Unified Debugger on Windows OS when debug server is piped
-* Fixed an issue when `--upload-port <http://docs.platformio.org/page/userguide/cmd_run.html#cmdoption-platformio-run-upload-port>`__ CLI flag does not override declared  `upload_port <http://docs.platformio.org/page/projectconf/section_env_upload.html#upload-port>`_ option in `"platformio.ini" (Project Configuration File) <https://docs.platformio.org/page/projectconf.html>`__
+* Fixed an issue when `--upload-port <http://docs.platformio.org/page/userguide/cmd_run.html#cmdoption-platformio-run-upload-port>`__ CLI flag does not override declared  `upload_port <http://docs.platformio.org/page/projectconf/section_env_upload.html#upload-port>`__ option in `"platformio.ini" (Project Configuration File) <https://docs.platformio.org/page/projectconf.html>`__
 
 4.0.2 (2019-08-23)
 ~~~~~~~~~~~~~~~~~~
diff --git a/platformio/project/config.py b/platformio/project/config.py
index 9a23d494..6ca36a14 100644
--- a/platformio/project/config.py
+++ b/platformio/project/config.py
@@ -312,6 +312,9 @@ class ProjectConfig(object):
         return json.dumps(result)
 
     def save(self, path=None):
+        path = path or self.path
+        if path in self._instances:
+            del self._instances[path]
         with open(path or self.path, "w") as fp:
             fp.write(CONFIG_HEADER)
             self._parser.write(fp)