From 4943f167de2b2a15171f7a655c58f56c6e7ca320 Mon Sep 17 00:00:00 2001
From: Jesse Glick <jglick@cloudbees.com>
Date: Thu, 12 Dec 2024 16:40:26 -0500
Subject: [PATCH] Recover views after error in `Jenkins.load` (#10023)

* Recover views after error in `Jenkins.load`

* Prevent infinite recursion in `Jenkins/sidepanel.jelly` when `Jenkins.primaryView` is null

---------

Co-authored-by: Tim Jacomb <21194782+timja@users.noreply.github.com>
---
 core/src/main/java/jenkins/model/Jenkins.java    | 14 +++++++++++---
 .../jenkins/model/Jenkins/sidepanel.jelly        |  7 ++++++-
 .../src/test/java/jenkins/model/JenkinsTest.java | 16 ++++++++++++++++
 3 files changed, 33 insertions(+), 4 deletions(-)

diff --git a/core/src/main/java/jenkins/model/Jenkins.java b/core/src/main/java/jenkins/model/Jenkins.java
index eee96b5bca05..e643e848dd9b 100644
--- a/core/src/main/java/jenkins/model/Jenkins.java
+++ b/core/src/main/java/jenkins/model/Jenkins.java
@@ -3297,11 +3297,19 @@ public void load() throws IOException {
         if (cfg.exists()) {
             // reset some data that may not exist in the disk file
             // so that we can take a proper compensation action later.
+            String originalPrimaryView = primaryView;
+            List<View> originalViews = new ArrayList<>(views);
             primaryView = null;
             views.clear();
-
-            // load from disk
-            cfg.unmarshal(Jenkins.this);
+            try {
+                // load from disk
+                cfg.unmarshal(Jenkins.this);
+            } catch (IOException | RuntimeException x) {
+                primaryView = originalPrimaryView;
+                views.clear();
+                views.addAll(originalViews);
+                throw x;
+            }
         }
         // initialize views by inserting the default view if necessary
         // this is both for clean Jenkins and for backward compatibility.
diff --git a/core/src/main/resources/jenkins/model/Jenkins/sidepanel.jelly b/core/src/main/resources/jenkins/model/Jenkins/sidepanel.jelly
index 9ddff73647d6..e413712d6e7c 100644
--- a/core/src/main/resources/jenkins/model/Jenkins/sidepanel.jelly
+++ b/core/src/main/resources/jenkins/model/Jenkins/sidepanel.jelly
@@ -23,4 +23,9 @@ THE SOFTWARE.
 -->
 
 <?jelly escape-by-default='true'?>
-<st:include it="${it.primaryView}" page="sidepanel.jelly" xmlns:st="jelly:stapler" />
\ No newline at end of file
+<j:jelly xmlns:j="jelly:core" xmlns:st="jelly:stapler">
+    <j:set var="primaryView" value="${it.primaryView}"/>
+    <j:if test="${primaryView != null}">
+        <st:include it="${primaryView}" page="sidepanel.jelly"/>
+    </j:if>
+</j:jelly>
diff --git a/test/src/test/java/jenkins/model/JenkinsTest.java b/test/src/test/java/jenkins/model/JenkinsTest.java
index 8469c9b46c36..acef3b6a2300 100644
--- a/test/src/test/java/jenkins/model/JenkinsTest.java
+++ b/test/src/test/java/jenkins/model/JenkinsTest.java
@@ -30,9 +30,11 @@
 import static org.awaitility.Awaitility.await;
 import static org.hamcrest.MatcherAssert.assertThat;
 import static org.hamcrest.Matchers.arrayContaining;
+import static org.hamcrest.Matchers.contains;
 import static org.hamcrest.Matchers.containsString;
 import static org.hamcrest.Matchers.equalTo;
 import static org.hamcrest.Matchers.is;
+import static org.hamcrest.Matchers.isA;
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertFalse;
 import static org.junit.Assert.assertNotNull;
@@ -46,6 +48,7 @@
 import hudson.XmlFile;
 import hudson.init.InitMilestone;
 import hudson.init.Initializer;
+import hudson.model.AllView;
 import hudson.model.Computer;
 import hudson.model.Failure;
 import hudson.model.FreeStyleProject;
@@ -101,6 +104,7 @@
 import org.junit.Test;
 import org.junit.experimental.categories.Category;
 import org.junit.rules.TemporaryFolder;
+import org.jvnet.hudson.reactor.ReactorException;
 import org.jvnet.hudson.test.Issue;
 import org.jvnet.hudson.test.JenkinsRule;
 import org.jvnet.hudson.test.JenkinsRule.WebClient;
@@ -755,4 +759,16 @@ public String getUrlName() {
             return null;
         }
     }
+
+    @Test
+    public void reloadViews() throws Exception {
+        assertThat(j.jenkins.getPrimaryView(), isA(AllView.class));
+        assertThat(j.jenkins.getViews(), contains(isA(AllView.class)));
+        Files.writeString(j.jenkins.getConfigFile().getFile().toPath(), "<broken");
+        assertThrows(ReactorException.class, j.jenkins::reload);
+        j.createWebClient().goTo("manage/");
+        assertThat(j.jenkins.getPrimaryView(), isA(AllView.class));
+        assertThat(j.jenkins.getViews(), contains(isA(AllView.class)));
+    }
+
 }