Added feature flag to toggle F command support

Defaults to off, set feature.supportFAsCommand to true to enable.

src/octoprint/plugins/virtual_printer/virtual.py

@@ -77,6 +77,7 @@ class VirtualPrinter(object):
 
 		self._okBeforeCommandOutput = settings().getBoolean(["devel", "virtualPrinter", "okBeforeCommandOutput"])
 		self._supportM112 = settings().getBoolean(["devel", "virtualPrinter", "supportM112"])
+		self._supportF = settings().getBoolean(["devel", "virtualPrinter", "supportF"])
 
 		self._sendWait = settings().getBoolean(["devel", "virtualPrinter", "sendWait"])
 		self._waitInterval = settings().getFloat(["devel", "virtualPrinter", "waitInterval"])
@@ -241,7 +242,12 @@ class VirtualPrinter(object):
 		self._send("Active Extruder: %d" % self.currentExtruder)
 
 	def _gcode_F(self, code, data):
-		self._send("echo:changed F value")
+		if self._supportF:
+			self._send("echo:changed F value")
+			return False
+		else:
+			self._send("Error: Unknown command F")
+			return True
 
 	def _gcode_M104(self, data):
 		self._parseHotendCommand(data)

src/octoprint/settings.py

@@ -166,7 +166,8 @@ default_settings = {
 		"keyboardControl": True,
 		"pollWatched": False,
 		"ignoreIdenticalResends": False,
-		"identicalResendsCountdown": 7
+		"identicalResendsCountdown": 7,
+		"supportFAsCommand": False
 	},
 	"folder": {
 		"uploads": None,
@@ -310,7 +311,8 @@ default_settings = {
 			"sendWait": True,
 			"waitInterval": 1.0,
 			"supportM112": True,
-			"echoOnM117": True
+			"echoOnM117": True,
+			"supportF": False
 		}
 	}
 }

src/octoprint/util/comm.py

@@ -2499,7 +2499,7 @@ def gcode_command_for_cmd(cmd):
 		return values["commandGM"]
 	elif "commandT" in values and values["commandT"]:
 		return values["commandT"]
-	elif "commandF" in values and values["commandF"]:
+	elif settings().getBoolean(["feature", "supportFAsCommand"]) and "commandF" in values and values["commandF"]:
 		return values["commandF"]
 	else:
 		# this should never happen