Add YAML test, too, for #497

yaml/src/test/java/com/fasterxml/jackson/dataformat/yaml/failing/UnicodeYAMLRead497Test.java

@@ -0,0 +1,46 @@
+package com.fasterxml.jackson.dataformat.yaml.failing;
+
+import java.nio.charset.StandardCharsets;
+
+import com.fasterxml.jackson.core.JsonParser;
+import com.fasterxml.jackson.core.JsonToken;
+
+import com.fasterxml.jackson.dataformat.yaml.*;
+
+// [dataformats-text#497]: 3-byte UTF-8 character at end of content
+public class UnicodeYAMLRead497Test extends ModuleTestBase
+{
+    private final YAMLMapper MAPPER = newObjectMapper();
+
+    // [dataformats-text#497]
+    public void testUnicodeAtEnd() throws Exception
+    {
+        // Had to find edge condition, these would do:
+        _testUnicodeAtEnd(1024);
+        _testUnicodeAtEnd(2048);
+        _testUnicodeAtEnd(3072);
+        _testUnicodeAtEnd(4096);
+    }
+
+    void _testUnicodeAtEnd(int LEN) throws Exception
+    {
+        StringBuilder sb = new StringBuilder(LEN + 2);
+        sb.append("key: ");
+        StringBuilder valueBuffer = new StringBuilder();
+
+        while ((sb.length() + valueBuffer.length()) < LEN) {
+            valueBuffer.append('a');
+        }
+        valueBuffer.append('\u5496');
+
+        sb.append(valueBuffer);
+        final byte[] doc = sb.toString().getBytes(StandardCharsets.UTF_8);
+
+        try (JsonParser p = MAPPER.createParser(doc)) {
+            assertToken(JsonToken.START_OBJECT, p.nextToken());
+            assertEquals("key", p.nextFieldName());
+            assertToken(JsonToken.VALUE_STRING, p.nextToken());
+            assertEquals(valueBuffer.toString(), p.getText());
+        }
+    }
+}