Don't crash when serial port gets disconnected

AVRsack/ASSerial.h

@@ -10,6 +10,12 @@
 
 extern NSString * kASSerialPortsChanged;
 
+@interface NSFileHandle (ExceptionSafety)
+
+- (NSData *)availableDataIgnoringExceptions;
+
+@end
+
 @interface ASSerial : NSObject
 
 + (NSString *) fileNameForPort:(NSString *)port;

AVRsack/ASSerial.mm

@@ -17,6 +17,19 @@ static NSMutableDictionary *    savedAttrs;
 
 NSString * kASSerialPortsChanged = @"PortsChanged";
 
+@implementation NSFileHandle (ExceptionSafety)
+
+- (NSData *)availableDataIgnoringExceptions {
+    @try {
+        return [self availableData];
+    }
+    @catch (NSException *exception) {
+        return [NSData data];
+    }
+}
+
+@end
+
 @implementation ASSerial
 
 + (void)initialize {

AVRsack/ASSerialWin.swift

@@ -146,7 +146,7 @@ class ASSerialWin: NSWindowController {
                 serialData  = ""
                 logView.setString(serialData)
                 portHandle!.readabilityHandler = {(handle) in
-                    let newData         = handle.availableData
+                    let newData         = handle.availableDataIgnoringExceptions()
                     let newString       = NSString(data: newData, encoding: NSASCIIStringEncoding)!
                     self.serialData    += newString
                     dispatch_async(dispatch_get_main_queue(), { () -> Void in