Don't run the automatic registration during test execution

If the IDE is running because we are executing automated tests it
doesn't make sense to run this registration job.

Fixes : eclipse-platform#2245

bundles/org.eclipse.ui.ide.application/src/org/eclipse/ui/internal/ide/application/IDEWorkbenchAdvisor.java

@@ -226,7 +226,7 @@ public void initialize(IWorkbenchConfigurer configurer) {
 			jfaceComparatorIsSet = true;
 		}
 
-		if (!Platform.inDevelopmentMode()) {
+		if (!Platform.inDevelopmentMode() && !JUnitTestUtil.isJunitTestRunning()) {
 			new AutoRegisterSchemeHandlersJob().schedule();
 		}
 	}

bundles/org.eclipse.ui.ide.application/src/org/eclipse/ui/internal/ide/application/JUnitTestUtil.java

@@ -0,0 +1,56 @@
+/*******************************************************************************
+ * Copyright (c) 2024 SAP SE.
+ *
+ * This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License 2.0
+ * which accompanies this distribution, and is available at
+ * https://www.eclipse.org/legal/epl-2.0/
+ *
+ * SPDX-License-Identifier: EPL-2.0
+ *
+ * Contributors:
+ *     Matthias Becker / Sebastian Ratz - initial API and implementation
+ *******************************************************************************/
+package org.eclipse.ui.internal.ide.application;
+
+import java.util.Set;
+import java.util.concurrent.atomic.AtomicBoolean;
+
+import org.eclipse.core.runtime.Platform;
+import org.eclipse.core.runtime.ServiceCaller;
+import org.eclipse.osgi.service.environment.EnvironmentInfo;
+
+public class JUnitTestUtil {
+	private static Boolean cachedIsJunitTestRunning = null;
+
+	public static boolean isJunitTestRunning() {
+		if (cachedIsJunitTestRunning == null) {
+			try {
+				if (Platform.isRunning()) {
+					AtomicBoolean result = new AtomicBoolean();
+					cachedIsJunitTestRunning = ServiceCaller.callOnce(JUnitTestUtil.class, EnvironmentInfo.class, envInfo -> {
+						String application = envInfo.getProperty("eclipse.application"); //$NON-NLS-1$
+						result.set(application != null && Set.of( //
+								// see org.eclipse.pde.internal.launching.IPDEConstants
+								"org.eclipse.pde.junit.runtime.nonuithreadtestapplication", // //$NON-NLS-1$
+								"org.eclipse.pde.junit.runtime.uitestapplication", // //$NON-NLS-1$
+								"org.eclipse.pde.junit.runtime.coretestapplication", // //$NON-NLS-1$
+								// see org.eclipse.tycho.surefire.AbstractTestMojo
+								"org.eclipse.tycho.surefire.osgibooter.uitest", //$NON-NLS-1$
+								"org.eclipse.tycho.surefire.osgibooter.headlesstest") // //$NON-NLS-1$
+								.contains(application));
+					});
+					cachedIsJunitTestRunning = result.get();
+				} else {
+					cachedIsJunitTestRunning = true; // probably
+				}
+			} catch (Throwable t) {
+				// log
+				cachedIsJunitTestRunning = false;
+			}
+		}
+
+		return cachedIsJunitTestRunning;
+	}
+
+}