Fixed a regression bug when opening device monitor without any filters // Resolve #4363

HISTORY.rst

@@ -13,6 +13,11 @@ PlatformIO Core 6
 
 **A professional collaborative platform for declarative, safety-critical, and test-driven embedded development.**
 
+6.1.3 (2022-07-??)
+~~~~~~~~~~~~~~~~~~
+
+* Fixed a regression bug when opening device monitor without any filters (`issue #4363 <https://github.com/platformio/platformio-core/issues/4363>`_)
+
 6.1.2 (2022-07-18)
 ~~~~~~~~~~~~~~~~~~
 

platformio/device/monitor/command.py

@@ -139,6 +139,7 @@ def device_monitor_cmd(**options):
         )
 
     # check for unknown filters
+    if options["filters"]:
         known_filters = set(get_available_filters())
         unknown_filters = set(options["filters"]) - known_filters
         if unknown_filters: