From 74a4104259e83b302d139fbc4216f9e3b2fe3c3e Mon Sep 17 00:00:00 2001
From: exceptionfactory <exceptionfactory@apache.org>
Date: Wed, 6 Apr 2022 11:26:08 -0500
Subject: [PATCH] NIFI-9882 Updated HtmlDocumentationWriter to avoid writing
 null characters

This closes #5935

Signed-off-by: Mike Thomsen <mthomsen@apache.org>
---
 .../html/HtmlDocumentationWriter.java         | 22 +++++++++------
 .../html/HtmlDocumentationWriterTest.java     | 28 ++++++++++---------
 2 files changed, 28 insertions(+), 22 deletions(-)

diff --git a/nifi-nar-bundles/nifi-framework-bundle/nifi-framework/nifi-documentation/src/main/java/org/apache/nifi/documentation/html/HtmlDocumentationWriter.java b/nifi-nar-bundles/nifi-framework-bundle/nifi-framework/nifi-documentation/src/main/java/org/apache/nifi/documentation/html/HtmlDocumentationWriter.java
index 90209cc571..8464143ce1 100644
--- a/nifi-nar-bundles/nifi-framework-bundle/nifi-framework/nifi-documentation/src/main/java/org/apache/nifi/documentation/html/HtmlDocumentationWriter.java
+++ b/nifi-nar-bundles/nifi-framework-bundle/nifi-framework/nifi-documentation/src/main/java/org/apache/nifi/documentation/html/HtmlDocumentationWriter.java
@@ -843,16 +843,20 @@ public class HtmlDocumentationWriter implements DocumentationWriter {
     protected final static void writeSimpleElement(final XMLStreamWriter writer, final String elementName,
             final String characters, boolean strong, String id) throws XMLStreamException {
         writer.writeStartElement(elementName);
-        if (id != null) {
-            writer.writeAttribute("id", id);
-        }
-        if (strong) {
-            writer.writeStartElement("strong");
-        }
-        writer.writeCharacters(characters);
-        if (strong) {
-            writer.writeEndElement();
+
+        if (characters != null) {
+            if (id != null) {
+                writer.writeAttribute("id", id);
+            }
+            if (strong) {
+                writer.writeStartElement("strong");
+            }
+            writer.writeCharacters(characters);
+            if (strong) {
+                writer.writeEndElement();
+            }
         }
+
         writer.writeEndElement();
     }
 
diff --git a/nifi-nar-bundles/nifi-framework-bundle/nifi-framework/nifi-documentation/src/test/java/org/apache/nifi/documentation/html/HtmlDocumentationWriterTest.java b/nifi-nar-bundles/nifi-framework-bundle/nifi-framework/nifi-documentation/src/test/java/org/apache/nifi/documentation/html/HtmlDocumentationWriterTest.java
index c37ebeb36b..89bd6a566d 100644
--- a/nifi-nar-bundles/nifi-framework-bundle/nifi-framework/nifi-documentation/src/test/java/org/apache/nifi/documentation/html/HtmlDocumentationWriterTest.java
+++ b/nifi-nar-bundles/nifi-framework-bundle/nifi-framework/nifi-documentation/src/test/java/org/apache/nifi/documentation/html/HtmlDocumentationWriterTest.java
@@ -32,21 +32,20 @@ import org.apache.nifi.nar.ExtensionManager;
 import org.apache.nifi.nar.StandardExtensionDiscoveringManager;
 import org.apache.nifi.reporting.InitializationException;
 import org.apache.nifi.reporting.ReportingTask;
-import org.junit.Assert;
-import org.junit.Before;
-import org.junit.Test;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.BeforeEach;
 
 import java.io.ByteArrayOutputStream;
 import java.io.IOException;
 
 import static org.apache.nifi.documentation.html.XmlValidator.assertContains;
-import static org.junit.Assert.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertEquals;
 
 public class HtmlDocumentationWriterTest {
 
     private ExtensionManager extensionManager;
 
-    @Before
+    @BeforeEach
     public void setup() {
         extensionManager = new StandardExtensionDiscoveringManager();
     }
@@ -89,6 +88,9 @@ public class HtmlDocumentationWriterTest {
         assertContains(results, "PKCS12");
         assertContains(results, "Sensitive Property: true");
 
+        // property with null default value
+        assertContains(results, "Keystore Password</td><td></td>");
+
         // restricted
         assertContains(results, "controller service restriction description");
 
@@ -101,11 +103,11 @@ public class HtmlDocumentationWriterTest {
         assertContains(results, "Not Specified");
 
         // verify the right OnRemoved and OnShutdown methods were called
-        Assert.assertEquals(0, controllerService.getOnRemovedArgs());
-        Assert.assertEquals(0, controllerService.getOnRemovedNoArgs());
+        assertEquals(0, controllerService.getOnRemovedArgs());
+        assertEquals(0, controllerService.getOnRemovedNoArgs());
 
-        Assert.assertEquals(1, controllerService.getOnShutdownArgs());
-        Assert.assertEquals(1, controllerService.getOnShutdownNoArgs());
+        assertEquals(1, controllerService.getOnShutdownArgs());
+        assertEquals(1, controllerService.getOnShutdownNoArgs());
     }
 
     @Test
@@ -149,11 +151,11 @@ public class HtmlDocumentationWriterTest {
         assertContains(results, "Not Specified");
 
         // verify the right OnRemoved and OnShutdown methods were called
-        Assert.assertEquals(0, reportingTask.getOnRemovedArgs());
-        Assert.assertEquals(0, reportingTask.getOnRemovedNoArgs());
+        assertEquals(0, reportingTask.getOnRemovedArgs());
+        assertEquals(0, reportingTask.getOnRemovedNoArgs());
 
-        Assert.assertEquals(1, reportingTask.getOnShutdownArgs());
-        Assert.assertEquals(1, reportingTask.getOnShutdownNoArgs());
+        assertEquals(1, reportingTask.getOnShutdownArgs());
+        assertEquals(1, reportingTask.getOnShutdownNoArgs());
     }
 
     @Test