Merge pull request #2919 from olivergondza/visiblity-filter

[FIXED JENKINS-40545] Diagnose NPE in DescriptorVisibilityFilter.apply

core/src/main/java/hudson/model/DescriptorVisibilityFilter.java

@@ -68,6 +68,11 @@ public abstract class DescriptorVisibilityFilter implements ExtensionPoint {
         List<T> r = new ArrayList<T>();
         Class<?> contextClass = context == null ? null : context.getClass();
 
+        if (source == null) {
+            // JENKINS-40545: throwing instead of logging so jelly can amend the actual jelly expression that failed.
+            throw new NullPointerException("Descriptor list is null for context '" + contextClass + "' in thread '" + Thread.currentThread().getName() + "'");
+        }
+
         OUTER:
         for (T d : source) {
             if (LOGGER.isLoggable(Level.FINE)) {

test/src/test/java/hudson/model/DescriptorVisibilityFilterTest.java

+package hudson.model;
+
+import static org.hamcrest.Matchers.containsString;
+import static org.hamcrest.Matchers.emptyIterable;
+import static org.hamcrest.Matchers.endsWith;
+import static org.hamcrest.Matchers.not;
+import static org.hamcrest.Matchers.allOf;
+import static org.junit.Assert.*;
+
+import com.gargoylesoftware.htmlunit.html.HtmlPage;
+import org.junit.Rule;
+import org.junit.Test;
+import org.jvnet.hudson.test.Issue;
+import org.jvnet.hudson.test.JenkinsRule;
+import org.jvnet.hudson.test.LoggerRule;
+import org.jvnet.hudson.test.TestExtension;
+
+import java.util.logging.Level;
+import java.util.logging.LogRecord;
+
+public class DescriptorVisibilityFilterTest {
+
+    @Rule public JenkinsRule j = new JenkinsRule();
+
+    @Rule public LoggerRule logger = new LoggerRule();
+
+    @Test @Issue("JENKINS-40545")
+    public void jenkins40545() throws Exception {
+        logger.record("hudson.ExpressionFactory2$JexlExpression", Level.WARNING);
+        logger.record("hudson.model.DescriptorVisibilityFilter", Level.WARNING);
+        logger.capture(10);
+        HtmlPage page = j.createWebClient().goTo("jenkins40545");
+        assertThat(logger.getRecords(), not(emptyIterable()));
+        for (LogRecord record : logger.getRecords()) {
+            String message = record.getMessage();
+            assertThat(message, allOf(
+                    containsString("Descriptor list is null for context 'class hudson.model.DescriptorVisibilityFilterTest$Jenkins40545'"),
+                    containsString("DescriptorVisibilityFilterTest/Jenkins40545/index.jelly"),
+                    not(endsWith("NullPointerException"))
+            ));
+        }
+
+        assertThat(page.getWebResponse().getContentAsString(), containsString("descriptors found: .")); // No output written from expression
+    }
+
+    @TestExtension("jenkins40545")
+    public static final class Jenkins40545 implements UnprotectedRootAction {
+
+        @Override public String getIconFileName() {
+            return "notepad.png";
+        }
+
+        @Override public String getDisplayName() {
+            return "jenkins40545";
+        }
+
+        @Override public String getUrlName() {
+            return "jenkins40545";
+        }
+    }
+}

test/src/test/resources/hudson/model/DescriptorVisibilityFilterTest/Jenkins40545/index.jelly

+<?jelly escape-by-default='true'?>
+<j:jelly xmlns:j="jelly:core" xmlns:l="/lib/layout">
+    <l:layout norefresh="true">
+        descriptors found: ${h.filterDescriptors(it, no_descriptors_here).size()}.
+    </l:layout>
+</j:jelly>