Unitialized variable bug: when filament load/unload is canceled, stop…

…Motor() would be called. But startMotor() may not have been called in which case state saved by startMotor() is not initialized. Thus, when that state is used by stopMotor() undefined things can happen -- motors disabled that shouldn't be, digipots set to invalid values, etc.

firmware/src/MightyBoard/shared/Menu.cc

@@ -633,18 +633,28 @@ void FilamentScreen::startMotor(){
 	steppers::setTargetNew(target, 0, interval, 0x1f);
 	filamentTimer.clear();
 	filamentTimer.start(300000000); //5 minutes
+
+	motorStarted = true;
 }
 
-void FilamentScreen::stopMotor(){
-	steppers::abort();
-	steppers::deprimeEnable(true);
+void FilamentScreen::stopMotor() {
+     if ( !motorStarted ) return;
+
+     // Next call will disable all the axes
+     steppers::abort();
+
+     // Next call isn't presently needed: steppers::abort() will do it
+     // steppers::deprimeEnable(true);
 
-	//Restore the enabled axis
-	for (uint8_t i = 0; i < STEPPER_COUNT; i++)
-		steppers::enableAxis(i, restoreAxesEnabled & _BV(i));
+     //Restore the enabled axis
+     for (uint8_t i = 0; i < STEPPER_COUNT; i++)
+	  steppers::enableAxis(i, restoreAxesEnabled & _BV(i));
 
-	//Restore the digi pot setting from entry
-	steppers::setAxisPotValue(axisID, digiPotOnEntry);
+     // Force enable
+     stepperAxisSetHardwareEnabledToMatch(restoreAxesEnabled);
+
+     //Restore the digi pot setting from entry
+     steppers::setAxisPotValue(axisID, digiPotOnEntry);
 }
 
 void FilamentScreen::update(LiquidCrystalSerial& lcd, bool forceRedraw) {
@@ -750,6 +760,7 @@ void FilamentScreen::update(LiquidCrystalSerial& lcd, bool forceRedraw) {
 			stopMotor();
 			Motherboard::interfaceBlinkOff();
 			_delay_us(1000000);
+			interface::popScreen();
 			break;
 		case FILAMENT_TIMEOUT:
 			/// filament motor has been running for 5 minutes
@@ -771,22 +782,22 @@ void FilamentScreen::setScript(FilamentScript script) {
 	switch(script) {
 	case FILAMENT_RIGHT_FOR:
 		toolID = 0;
-		axisID = 3;
+		axisID = A_AXIS;
 		forward = true;
 		break;
 	case FILAMENT_LEFT_FOR:
 		toolID = 1;
-		axisID = 4;
+		axisID = B_AXIS;
 		forward = true;
 		break;
 	case FILAMENT_RIGHT_REV:
 		toolID = 0;
-		axisID = 3;
+		axisID = A_AXIS;
 		forward = false;
 		break;
 	case FILAMENT_LEFT_REV:
 		toolID = 1;
-		axisID = 4;
+		axisID = B_AXIS;
 		forward = false;
 		break;
 	}
@@ -834,6 +845,7 @@ void FilamentScreen::notifyButtonPressed(ButtonArray::ButtonName button) {
 }
 
 void FilamentScreen::reset() {
+        motorStarted = false;
 	needsRedraw = false;
 	toggleBlink = false;
 	lastHeatIndex = 0;
@@ -3171,7 +3183,6 @@ void CancelBuildMenu::handleSelect(uint8_t index) {
 		if ( state != 0 ) {
 			// We're merely paused while printing
 			interface::popScreen();
-			interface::popScreen();
 			if ( (state != 2) || (0 == eeprom::getEeprom8(eeprom_offsets::HEAT_DURING_PAUSE, DEFAULT_HEAT_DURING_PAUSE)) )
 				// Turn heat off if cancelling a utility filament load/unload or if canceling
 				//   a filament load during pause and HEAT_DURING_PAUSE is disabled

firmware/src/MightyBoard/shared/Menu.hh

@@ -247,6 +247,7 @@ private:
 	bool forward;
 	bool helpText;
 	bool needsRedraw;
+        bool motorStarted;
 
 	void startMotor();
 	void stopMotor();