bugfix: char class casefold for certain chars

When a character is less than or equal to single byte size (0xff),
yet it takes more than 1 byte in the current encoding, the
case folding code incorrectly put it in bitset instead of code
range. As a result, for utf8 encoding, casefold works incorrectly
on characters in range \u0080 to \u00ff (latin1 supplement).

Before fix:

* `"\u00c2"` `[\u00e0-\u00e5]` returns false
* `"\u00c2"` `[\u00e2]` returns false
* `"\u00c2"` `\u00e2` returns true

src/org/joni/ApplyCaseFold.java

@@ -41,7 +41,7 @@ public void apply(int from, int[]to, int length, Object o) {
 
             if (Config.CASE_FOLD_IS_APPLIED_INSIDE_NEGATIVE_CCLASS) {
                 if ((inCC && !cc.isNot()) || (!inCC && cc.isNot())) {
-                    if (enc.minLength() > 1 || to[0] >= BitSet.SINGLE_BYTE_SIZE) {
+                    if (enc.minLength() > 1 || to[0] >= BitSet.SINGLE_BYTE_SIZE || enc.codeToMbcLength(to[0]) > 1) {
                         cc.addCodeRange(env, to[0], to[0]);
                     } else {
                         /* /(?i:[^A-C])/.match("a") ==> fail. */

test/org/joni/test/TestJava.java

@@ -0,0 +1,55 @@
+/*
+ * Permission is hereby granted, free of charge, to any person obtaining a copy of
+ * this software and associated documentation files (the "Software"), to deal in
+ * the Software without restriction, including without limitation the rights to
+ * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
+ * of the Software, and to permit persons to whom the Software is furnished to do
+ * so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+package org.joni.test;
+
+import org.jcodings.Encoding;
+import org.jcodings.specific.UTF8Encoding;
+import org.joni.Option;
+import org.joni.Syntax;
+
+public class TestJava extends Test {
+
+    public int option() {
+        return Option.DEFAULT;
+    }
+
+    public Encoding encoding() {
+        return UTF8Encoding.INSTANCE;
+    }
+
+    public String testEncoding() {
+        return "utf-8";
+    }
+
+    public Syntax syntax() {
+        return Syntax.Java;
+    }
+
+    public void test() throws InterruptedException {
+        // test ignorecase for Latin-1 Supplement
+        x2s("[\\u00e0-\\u00e5]", "\u00c2", 0, 2, Option.IGNORECASE);
+        x2s("[\\u00e2]", "\u00c2", 0, 2, Option.IGNORECASE);
+        x2s("\\u00e2", "\u00c2", 0, 2, Option.IGNORECASE);
+    }
+
+    public static void main(String[] args) throws Throwable {
+        new TestJava().run();
+    }
+}