An empty string could still be returned when a non empty string is required. Related to #3381

Author: Federico Fissore

arduino-core/src/processing/app/PreferencesData.java

@@ -146,6 +146,11 @@ static public String get(String attribute, String defaultValue) {
     return (value == null) ? defaultValue : value;
   }
 
+  static public String getNonEmpty(String attribute, String defaultValue) {
+    String value = get(attribute, defaultValue);
+    return ("".equals(value)) ? defaultValue : value;
+  }
+
   public static boolean has(String key) {
     return prefs.containsKey(key);
   }

arduino-core/src/processing/app/Serial.java

@@ -50,27 +50,27 @@ public class Serial implements SerialPortEventListener {
   public Serial() throws SerialException {
     this(PreferencesData.get("serial.port"),
       PreferencesData.getInteger("serial.debug_rate", 9600),
-      PreferencesData.get("serial.parity", "N").charAt(0),
+      PreferencesData.getNonEmpty("serial.parity", "N").charAt(0),
       PreferencesData.getInteger("serial.databits", 8),
       PreferencesData.getFloat("serial.stopbits", 1));
   }
 
   public Serial(int irate) throws SerialException {
     this(PreferencesData.get("serial.port"), irate,
-      PreferencesData.get("serial.parity", "N").charAt(0),
+      PreferencesData.getNonEmpty("serial.parity", "N").charAt(0),
       PreferencesData.getInteger("serial.databits", 8),
       PreferencesData.getFloat("serial.stopbits", 1));
   }
 
   public Serial(String iname, int irate) throws SerialException {
-    this(iname, irate, PreferencesData.get("serial.parity", "N").charAt(0),
+    this(iname, irate, PreferencesData.getNonEmpty("serial.parity", "N").charAt(0),
       PreferencesData.getInteger("serial.databits", 8),
       PreferencesData.getFloat("serial.stopbits", 1));
   }
 
   public Serial(String iname) throws SerialException {
     this(iname, PreferencesData.getInteger("serial.debug_rate", 9600),
-      PreferencesData.get("serial.parity", "N").charAt(0),
+      PreferencesData.getNonEmpty("serial.parity", "N").charAt(0),
       PreferencesData.getInteger("serial.databits", 8),
       PreferencesData.getFloat("serial.stopbits", 1));
   }