PrettyPrintWriter fails to serialize characters in the Unicode Supplementary Multilingual Plane in XML 1.0 mode and XML 1.1 mode. Closes #337.

Author: basil

xstream-distribution/src/content/changes.html

@@ -38,6 +38,8 @@ <h2>Major changes</h2>
 	<ul>
 		<li>Support for Record types (contributed by Julia Boes and Chris Hegarty, both of Oracle).</li>
 		<li>Usage of Java generic types. Most code bases will still compile without change.</li>
+		<li>GPR:#337: PrettyPrintWriter supports now characters of the Unicode Supplementary Multilingual Plane (by
+		Basil Crow).</li>
 		<li>Support for fail-safe deserialization unless the parser is not directly involved (I/O or syntax error) as
 		combination of new method getLevel() of HierarchicalStreamReader and GHPR:#91.</li>
 		<li>GHI:#120: Add <em>Automatic-Module-Name</em> entry to XStream's manifests.</li>

xstream/src/java/com/thoughtworks/xstream/io/xml/PrettyPrintWriter.java

@@ -233,9 +233,7 @@ protected void writeText(final QuickWriter writer, final String text) {
     }
 
     private void writeText(final String text, final boolean isAttribute) {
-        final int length = text.length();
-        for (int i = 0; i < length; i++) {
-            final char c = text.charAt(i);
+        text.codePoints().forEach(c -> {
             switch (c) {
             case '\0':
                 if (mode == XML_QUIRKS) {
@@ -267,7 +265,7 @@ private void writeText(final String text, final boolean isAttribute) {
             case '\t':
             case '\n':
                 if (!isAttribute) {
-                    writer.write(c);
+                    writer.write(Character.toChars(c));
                     break;
                 }
                 //$FALL-THROUGH$
@@ -287,7 +285,7 @@ private void writeText(final String text, final boolean isAttribute) {
                         }
                     }
                     if (!replaced) {
-                        writer.write(c);
+                        writer.write(Character.toChars(c));
                     }
                 } else {
                     boolean replaced = false;
@@ -326,7 +324,7 @@ private void writeText(final String text, final boolean isAttribute) {
                     }
                 }
             }
-        }
+        });
     }
 
     @Override

xstream/src/test/com/thoughtworks/xstream/io/xml/PrettyPrintWriterTest.java

@@ -1,6 +1,6 @@
 /*
  * Copyright (C) 2004, 2005 Joe Walnes.
- * Copyright (C) 2006, 2007, 2008, 2013, 2018, 2023 XStream Committers.
+ * Copyright (C) 2006, 2007, 2008, 2013, 2018, 2023, 2024 XStream Committers.
  * All rights reserved.
  *
  * The software in this package is published under the terms of the BSD
@@ -397,6 +397,33 @@ public void testReplacesInvalidUnicodeCharactersInXml1_1ReplacementMode() {
         assertXmlProducedIs("<tag>&#xd7ff;&#xfffd;&#xfffd;\ue000\ufffd&#xfffd;&#xfffd;</tag>");
     }
 
+    public void testSupportsSupplementaryMultilingualPlaneInQuirks_Mode() {
+        writer = new PrettyPrintWriter(buffer, PrettyPrintWriter.XML_QUIRKS);
+        writer.startNode("tag");
+        writer.setValue("\uD83E\uDD8A");
+        writer.endNode();
+
+        assertXmlProducedIs("<tag>\uD83E\uDD8A</tag>");
+    }
+
+    public void testSupportsSupplementaryMultilingualPlaneInXml1_0Mode() {
+        writer = new PrettyPrintWriter(buffer, PrettyPrintWriter.XML_1_0);
+        writer.startNode("tag");
+        writer.setValue("\uD83E\uDD8A");
+        writer.endNode();
+
+        assertXmlProducedIs("<tag>\uD83E\uDD8A</tag>");
+    }
+
+    public void testSupportsSupplementaryMultilingualPlaneInXml1_1Mode() {
+        writer = new PrettyPrintWriter(buffer, PrettyPrintWriter.XML_1_1);
+        writer.startNode("tag");
+        writer.setValue("\uD83E\uDD8A");
+        writer.endNode();
+
+        assertXmlProducedIs("<tag>\uD83E\uDD8A</tag>");
+    }
+
     private String replace(final String in, final char what, final String with) {
         final int pos = in.indexOf(what);
         if (pos == -1) {