added contingency case in format pref scanning if there is no input

src/delombok/lombok/delombok/FormatPreferenceScanner.java

@@ -37,18 +37,18 @@ import java.util.Map;
  */
 public class FormatPreferenceScanner {
 	/** Checks validity of preferences, and returns with a non-null value if ALL format keys are available, thus negating the need for a scan. */
-	private FormatPreferences tryEasy(Map<String, String> preferences) {
+	private FormatPreferences tryEasy(Map<String, String> preferences, boolean force) {
 		int count = 0;
 		for (Map.Entry<String, String> e : preferences.entrySet()) {
 			if (!FormatPreferences.KEYS.containsKey(e.getKey())) throw new IllegalArgumentException("Unknown format key: " + e.getKey());
 			if (!"scan".equalsIgnoreCase(e.getValue())) count++;
 		}
-		if (count >= FormatPreferences.KEYS.size()) return new FormatPreferences(preferences, "\t", false);
+		if (force || count >= FormatPreferences.KEYS.size()) return new FormatPreferences(preferences, "\t", false);
 		return null;
 	}
 	
 	public FormatPreferences scan(Map<String, String> preferences, final CharSequence source) {
-		FormatPreferences fps = tryEasy(preferences);
+		FormatPreferences fps = tryEasy(preferences, source == null);
 		if (fps != null) return fps;
 		
 		try {
@@ -76,7 +76,7 @@ public class FormatPreferenceScanner {
 	}
 	
 	public FormatPreferences scan(Map<String, String> preferences, char[] source) {
-		FormatPreferences fps = tryEasy(preferences);
+		FormatPreferences fps = tryEasy(preferences, source == null);
 		if (fps != null) return fps;
 		
 		try {
@@ -87,7 +87,7 @@ public class FormatPreferenceScanner {
 	}
 	
 	public FormatPreferences scan(Map<String, String> preferences, Reader in) throws IOException {
-		FormatPreferences fps = tryEasy(preferences);
+		FormatPreferences fps = tryEasy(preferences, in == null);
 		if (fps != null) return fps;
 		
 		return scan_(preferences, in);