Issue checkstyle#5168: upgrades xml output to version 1.1

src/main/java/com/puppycrawl/tools/checkstyle/XMLLogger.java

@@ -96,7 +96,7 @@ protected void finishLocalSetup() {
 
     @Override
     public void auditStarted(AuditEvent event) {
-        writer.println("<?xml version=\"1.0\" encoding=\"UTF-8\"?>");
+        writer.println("<?xml version=\"1.1\" encoding=\"UTF-8\"?>");
 
         final String version = XMLLogger.class.getPackage().getImplementationVersion();
 
@@ -273,9 +273,7 @@ public static String encode(String value) {
                     break;
                 default:
                     if (Character.isISOControl(chr)) {
-                        // true escape characters need '&' before, but it also requires XML 1.1
-                        // until https://github.com/checkstyle/checkstyle/issues/5168
-                        sb.append("#x");
+                        sb.append("&#x");
                         sb.append(Integer.toHexString(chr));
                         sb.append(';');
                     }

src/test/java/com/puppycrawl/tools/checkstyle/MainTest.java

@@ -405,7 +405,7 @@ public void testExistingTargetFileXmlOutput(@SysErr Capturable systemErr,
         assertWithMessage("Unexpected output log")
             .that(systemOut.getCapturedData())
             .isEqualTo(addEndOfLine(
-            "<?xml version=\"1.0\" encoding=\"UTF-8\"?>",
+            "<?xml version=\"1.1\" encoding=\"UTF-8\"?>",
                 "<checkstyle version=\"" + version + "\">",
                 "<file name=\"" + expectedPath + "\">",
                 "</file>",

src/test/java/com/puppycrawl/tools/checkstyle/XMLLoggerTest.java

@@ -70,8 +70,8 @@ public void testEncode()
             {"�", "�"},
             {"&#0", "&#0"},
             {"�", "�"},
-            {"\u0001", "#x1;"},
-            {"\u0080", "#x80;"},
+            {"\u0001", ""},
+            {"\u0080", "€"},
         };
         for (String[] encoding : encodings) {
             final String encoded = XMLLogger.encode(encoding[0]);

src/test/resources/com/puppycrawl/tools/checkstyle/ant/checkstyleanttask/ExpectedCheckstyleAntTaskXmlOutput.xml

@@ -1,4 +1,4 @@
-<?xml version="1.0" encoding="UTF-8"?>
+<?xml version="1.1" encoding="UTF-8"?>
 <checkstyle version="6.16-SNAPSHOT">
 <file name="/home/vlad/projects/checkstyle/src/test/resources/com/puppycrawl/tools/checkstyle/ant/InputCheckstyleAntTaskError.java">
 <error line="7" severity="error" message="Line is longer than 70 characters (found 80)." source="com.puppycrawl.tools.checkstyle.checks.sizes.LineLengthCheck"/>

src/test/resources/com/puppycrawl/tools/checkstyle/xmllogger/ExpectedXMLLogger.xml

@@ -1,4 +1,4 @@
-<?xml version="1.0" encoding="UTF-8"?>
+<?xml version="1.1" encoding="UTF-8"?>
 <checkstyle version="">
 <file name="Test.java">
 </file>

src/test/resources/com/puppycrawl/tools/checkstyle/xmllogger/ExpectedXMLLoggerEmpty.xml

@@ -1,3 +1,3 @@
-<?xml version="1.0" encoding="UTF-8"?>
+<?xml version="1.1" encoding="UTF-8"?>
 <checkstyle version="">
 </checkstyle>

src/test/resources/com/puppycrawl/tools/checkstyle/xmllogger/ExpectedXMLLoggerError.xml

@@ -1,4 +1,4 @@
-<?xml version="1.0" encoding="UTF-8"?>
+<?xml version="1.1" encoding="UTF-8"?>
 <checkstyle version="">
 <file name="Test.java">
 <error line="1" column="1" severity="error" message="$0" source="com.puppycrawl.tools.checkstyle.XMLLoggerTest"/>

src/test/resources/com/puppycrawl/tools/checkstyle/xmllogger/ExpectedXMLLoggerErrorModuleId.xml

@@ -1,4 +1,4 @@
-<?xml version="1.0" encoding="UTF-8"?>
+<?xml version="1.1" encoding="UTF-8"?>
 <checkstyle version="">
 <error line="1" column="1" severity="error" message="$0" source="module"/>
 </checkstyle>

src/test/resources/com/puppycrawl/tools/checkstyle/xmllogger/ExpectedXMLLoggerErrorNullFileName.xml

@@ -1,4 +1,4 @@
-<?xml version="1.0" encoding="UTF-8"?>
+<?xml version="1.1" encoding="UTF-8"?>
 <checkstyle version="">
 <error line="1" column="1" severity="error" message="$0" source="com.puppycrawl.tools.checkstyle.XMLLoggerTest"/>
 </checkstyle>

src/test/resources/com/puppycrawl/tools/checkstyle/xmllogger/ExpectedXMLLoggerErrorZeroColumn.xml

@@ -1,4 +1,4 @@
-<?xml version="1.0" encoding="UTF-8"?>
+<?xml version="1.1" encoding="UTF-8"?>
 <checkstyle version="">
 <file name="Test.java">
 <error line="1" severity="error" message="$0" source="com.puppycrawl.tools.checkstyle.XMLLoggerTest"/>

src/test/resources/com/puppycrawl/tools/checkstyle/xmllogger/ExpectedXMLLoggerException.xml

@@ -1,4 +1,4 @@
-<?xml version="1.0" encoding="UTF-8"?>
+<?xml version="1.1" encoding="UTF-8"?>
 <checkstyle version="">
 <exception>
 <![CDATA[

src/test/resources/com/puppycrawl/tools/checkstyle/xmllogger/ExpectedXMLLoggerException2.xml

@@ -1,4 +1,4 @@
-<?xml version="1.0" encoding="UTF-8"?>
+<?xml version="1.1" encoding="UTF-8"?>
 <checkstyle version="">
 <file name="Test.java">
 <exception>

src/test/resources/com/puppycrawl/tools/checkstyle/xmllogger/ExpectedXMLLoggerException3.xml

@@ -1,4 +1,4 @@
-<?xml version="1.0" encoding="UTF-8"?>
+<?xml version="1.1" encoding="UTF-8"?>
 <checkstyle version="">
 <exception>
 <![CDATA[

src/test/resources/com/puppycrawl/tools/checkstyle/xmllogger/ExpectedXMLLoggerExceptionNullFileName.xml

@@ -1,4 +1,4 @@
-<?xml version="1.0" encoding="UTF-8"?>
+<?xml version="1.1" encoding="UTF-8"?>
 <checkstyle version="">
 <exception>
 <![CDATA[