Made communication mode more error resilient

octoprint/util/comm.py

@@ -581,6 +581,7 @@ class MachineCom(object):
 		startSeen = not settings().getBoolean(["feature", "waitForStartOnConnect"])
 		heatingUp = False
 		while True:
+			try:
 				line = self._readline()
 				if line == None:
 					break
@@ -795,6 +796,13 @@ class MachineCom(object):
 								self._sendNext()
 						elif "resend" in line.lower() or "rs" in line:
 							self._handleResendRequest(line)
+			except:
+				self._logger.exception("Something crashed inside the serial connection loop, please report this in OctoPrint's bug tracker:")
+
+				errorMsg = "Please see octoprint.log for details"
+				self._log(errorMsg)
+				self._errorValue = errorMsg
+				self._changeState(self.STATE_ERROR)
 		self._log("Connection closed, closing down monitor")
 
 	def _handleResendRequest(self, line):
@@ -849,7 +857,7 @@ class MachineCom(object):
 		return ret
 	
 	def close(self, isError = False):
-		if self._serial != None:
+		if self._serial is not None:
 			self._serial.close()
 			if isError:
 				self._changeState(self.STATE_CLOSED_WITH_ERROR)
@@ -867,7 +875,7 @@ class MachineCom(object):
 		# Make sure we are only handling one sending job at a time
 		with self._sendingLock:
 			self._logger.debug("Resending line %d, delta is %d, history log is %s items strong" % (self._currentLine - self._resendDelta, self._resendDelta, len(self._lastLines)))
-			cmd = self._lastLines[-(self._resendDelta+1)]
+			cmd = self._lastLines[-(self._resendDelta + 1)]
 			lineNumber = self._currentLine - self._resendDelta
 
 			self._doSendWithChecksum(cmd, lineNumber)