RealJenkinsRule should not overwrite JenkinsLocationConfiguration if otherwise set

[jglick]

For example you may wish to test behavior of Jenkins behind a reverse proxy and define a particular root URL explicitly.

[basil]

I don't suppose test coverage for this could be trivially added with e.g.

diff --git a/src/test/java/org/jvnet/hudson/test/RealJenkinsRuleTest.java b/src/test/java/org/jvnet/hudson/test/RealJenkinsRuleTest.java
index 6471f85..d437f57 100644
--- a/src/test/java/org/jvnet/hudson/test/RealJenkinsRuleTest.java
+++ b/src/test/java/org/jvnet/hudson/test/RealJenkinsRuleTest.java
@@ -60,6 +60,7 @@ import javax.servlet.ServletException;
 import javax.servlet.ServletRequest;
 import javax.servlet.ServletResponse;
 import jenkins.model.Jenkins;
+import jenkins.model.JenkinsLocationConfiguration;
 import org.apache.commons.io.FileUtils;
 import org.apache.commons.io.IOUtils;
 import org.hamcrest.core.IsNull;
@@ -201,6 +202,17 @@ public class RealJenkinsRuleTest {
         assertNull(Stapler.getCurrentRequest());
     }
 
+    @Test public void stepsDoNotOverwriteJenkinsLocationConfigurationIfOtherwiseSet() throws Throwable {
+        rr.then(RealJenkinsRuleTest::_stepsDoNotOverwriteJenkinsLocationConfigurationIfOtherwiseSet1);
+        rr.then(RealJenkinsRuleTest::_stepsDoNotOverwriteJenkinsLocationConfigurationIfOtherwiseSet2);
+    }
+    private static void _stepsDoNotOverwriteJenkinsLocationConfigurationIfOtherwiseSet1(JenkinsRule r) throws Throwable {
+        assertNotNull(JenkinsLocationConfiguration.get().getUrl());
+        JenkinsLocationConfiguration.get().setUrl("https://example.com/");
+    }
+    private static void _stepsDoNotOverwriteJenkinsLocationConfigurationIfOtherwiseSet2(JenkinsRule r) throws Throwable {
+        assertEquals("https://example.com/", JenkinsLocationConfiguration.get().getUrl());
+    }
 
     @Test
     public void test500Errors() throws IOException {

[jglick]

Yes, something along those lines should work for test coverage, will try it when I get a chance.