fix crash when hot-unplugging pen

2 files changed, 18 insertions, 6 deletions

diff --git a/smartpenmanager.cc b/smartpenmanager.cc
index 1eeb685..d375fea 100644
--- a/smartpenmanager.cc
+++ b/smartpenmanager.cc
@@ -197,9 +197,8 @@ void SmartpenManager::handleTimerNextTry()
 
 void SmartpenManager::processDeviceAdded(udev_device *dev)
 {
-	uint busnum = atol(udev_device_get_sysattr_value(dev, "busnum"));
-	uint devnum = atol(udev_device_get_sysattr_value(dev, "devnum"));
-	Smartpen::Address addr(busnum, devnum);
+	Smartpen::Address addr = getDeviceAddress(dev);
+	if (!addr.first && !addr.second) return;
 
 	QString name = parseUdevEscapedString(udev_device_get_property_value(dev, "ID_MODEL_ENC"));
 
@@ -223,9 +222,8 @@ void SmartpenManager::processDeviceAdded(udev_device *dev)
 
 void SmartpenManager::processDeviceRemoved(udev_device *dev)
 {
-	uint busnum = atol(udev_device_get_sysattr_value(dev, "busnum"));
-	uint devnum = atol(udev_device_get_sysattr_value(dev, "devnum"));
-	Smartpen::Address addr(busnum, devnum);
+	Smartpen::Address addr = getDeviceAddress(dev);
+	if (!addr.first && !addr.second) return;
 
 	qDebug() << "Device removed with address:" << addr;
 
@@ -325,3 +323,16 @@ QString SmartpenManager::parseUdevEscapedString(const char *s)
 	}
 	return r;
 }
+
+Smartpen::Address SmartpenManager::getDeviceAddress(udev_device *dev)
+{
+	const char *busnumS = udev_device_get_property_value(dev, "BUSNUM");
+	const char *devnumS = udev_device_get_property_value(dev, "DEVNUM");
+	if (!busnumS || !devnumS) {
+		qWarning() << "Cannot find busnum/devnum env var for udev device";
+		return Smartpen::Address();
+	}
+	uint busnum = atol(busnumS);
+	uint devnum = atol(devnumS);
+	return Smartpen::Address(busnum, devnum);
+}
diff --git a/smartpenmanager.h b/smartpenmanager.h
index a823709..6a5e39f 100644
--- a/smartpenmanager.h
+++ b/smartpenmanager.h
@@ -61,6 +61,7 @@ private:
 	void scheduleNextTry();
 
 	static QString parseUdevEscapedString(const char *s);
+	static Smartpen::Address getDeviceAddress(udev_device *dev);
 
 private:
 	udev *_udev;