Fixed alphabet for territory

Author: rijnb

src/main/java/com/mapcode/Decoder.java

@@ -645,15 +645,15 @@ static String decodeUTF16(final String mapcode) {
         return result;
     }
 
-    static String encodeUTF16(final String mapcode, int alphabetCode) {
+    static String encodeUTF16(final String mapcode, int alphabetCode) throws IllegalArgumentException {
         final String mapcodeToEncode;
         if (ASCII2LANGUAGE[alphabetCode][4] == 0x003f) {
 
             // Alphabet does not contain 'E'.
             if (mapcode.matches("^.*[EU].*")) {
                 final String unpacked = aeuUnpack(mapcode);
                 if (unpacked.isEmpty()) {
-                    throw new AssertionError("encodeToAlphabetCode: cannot encode '" + mapcode +
+                    throw new IllegalArgumentException("encodeToAlphabetCode: cannot encode '" + mapcode +
                             "' to alphabet " + alphabetCode + ' ' + Alphabet.fromCode(alphabetCode));
                 }
                 mapcodeToEncode = Encoder.aeuPack(unpacked, true);

src/main/java/com/mapcode/Mapcode.java

@@ -309,7 +309,7 @@ public static FormatType fromPrecision(final int precision) {
     public static FormatType getMapcodeFormatType(@Nonnull final String mapcode) throws IllegalArgumentException {
 
         // First, decode to ASCII.
-        final String decodedMapcode = convertStringToPlainAscii(mapcode.toUpperCase());
+        final String decodedMapcode = convertStringToPlainAscii(mapcode).toUpperCase();
 
         // Syntax needs to be OK.
         if (!PATTERN_MAPCODE.matcher(decodedMapcode).matches()) {
@@ -392,7 +392,8 @@ static String convertStringToPlainAscii(@Nonnull final String string) {
      * @param string   Any string.
      * @param alphabet Alphabet to convert to, may contain Unicode characters.
      * @return Converted mapcode.
-     * @throws IllegalArgumentException Thrown if mapcode has incorrect syntax.
+     * @throws IllegalArgumentException Thrown if string has incorrect syntax or if the string cannot be encoded in
+     *                                  the specified alphabet.
      */
     @Nonnull
     static String convertStringToAlphabet(@Nonnull final String string, @Nullable final Alphabet alphabet) throws IllegalArgumentException {

src/main/java/com/mapcode/MapcodeCodec.java

@@ -244,7 +244,7 @@ public static Point decode(
         checkNonnull("mapcode", mapcode);
 
         // Clean up mapcode.
-        String mapcodeClean = Mapcode.convertStringToPlainAscii(mapcode.trim().toUpperCase());
+        String mapcodeClean = Mapcode.convertStringToPlainAscii(mapcode.trim()).toUpperCase();
 
         // Determine territory from mapcode.
         final Territory territory;

src/main/java/com/mapcode/Territory.java

@@ -722,7 +722,7 @@ public enum NameFormat {
      *
      * @param format   Format to be used.
      * @param alphabet Alphabet. May be null.
-     * @return Mapcode
+     * @return Mapcode.
      */
     @Nonnull
     public String toNameFormat(@Nonnull final NameFormat format, @Nullable final Alphabet alphabet) {
@@ -738,7 +738,14 @@ public String toNameFormat(@Nonnull final NameFormat format, @Nullable final Alp
                 }
             }
         }
-        return (alphabet != null) ? Mapcode.convertStringToAlphabet(result, alphabet) : result;
+        if (alphabet != null) {
+            try {
+                result = Mapcode.convertStringToAlphabet(result, alphabet);
+            } catch (final IllegalArgumentException ignored) {
+                // Simply return result if translation to alphabet fails.
+            }
+        }
+        return result;
     }
 
     @Nonnull
@@ -862,7 +869,7 @@ private Territory(
     private static Territory createFromString(
             @Nonnull final String numericOrAlpha,
             @Nullable final ParentTerritory parentTerritory) throws UnknownTerritoryException {
-        final String trimmed = Mapcode.convertStringToPlainAscii(numericOrAlpha.trim().replace('_', '-').toUpperCase());
+        final String trimmed = Mapcode.convertStringToPlainAscii(numericOrAlpha.trim().replace('_', '-')).toUpperCase();
 
         // First, try as numeric code.
         try {

src/test/java/com/mapcode/MapcodeTest.java

@@ -114,6 +114,7 @@ public void checkConvertToAscii() {
         assertEquals("36228.92UW-TK", Mapcode.convertStringToPlainAscii("36228.92UW-TK"));
 
         // Check unicode characters.
+        assertEquals("GRC", Mapcode.convertStringToPlainAscii("\u0393\u03a8\u039e"));
         assertEquals("KM.8K", Mapcode.convertStringToPlainAscii("\u30c1\u30ca.8\u30c1"));
         assertEquals("HJ.Q2-Z", Mapcode.convertStringToPlainAscii("\u0397\u03a0.\u03982-\u0411"));
     }