Add failing test for #497 (#498)

Author: cowtowncoder

csv/src/test/java/com/fasterxml/jackson/dataformat/csv/failing/UnicodeRead497Test.java

@@ -0,0 +1,27 @@
+package com.fasterxml.jackson.dataformat.csv.failing;
+
+import java.nio.charset.StandardCharsets;
+
+import com.fasterxml.jackson.databind.*;
+
+import com.fasterxml.jackson.dataformat.csv.*;
+
+// [dataformats-text#497]: 3-byte UTF-8 character at end of content
+public class UnicodeRead497Test extends ModuleTestBase
+{
+    private final CsvMapper MAPPER = mapperForCsv();
+
+    // [dataformats-text#497]
+    public void testUnicodeAtEnd() throws Exception
+    {
+        StringBuilder sb = new StringBuilder(4001);
+        for (int i = 0; i < 4000; ++i) {
+            sb.append('a');
+        }
+        sb.append('\u5496');
+        String doc = sb.toString();
+        JsonNode o = MAPPER.reader() //.with(schema)
+                .readTree(doc.getBytes(StandardCharsets.UTF_8));
+        assertNotNull(o);
+    }
+}