Handle JavaMainSupport.getJavaCommand being null when not invoking Java main.

Author: peter-hofer

substratevm/src/com.oracle.svm.core/src/com/oracle/svm/core/jdk/management/Target_jdk_internal_vm_VMSupport.java

@@ -26,6 +26,7 @@
 
 package com.oracle.svm.core.jdk.management;
 
+import java.util.Objects;
 import java.util.Properties;
 
 import org.graalvm.nativeimage.ImageSingletons;
@@ -46,9 +47,10 @@ public final class Target_jdk_internal_vm_VMSupport {
     private static Properties initAgentProperties(Properties properties) {
         if (ImageSingletons.contains(JavaMainSupport.class)) {
             JavaMainSupport support = ImageSingletons.lookup(JavaMainSupport.class);
-            properties.setProperty("sun.jvm.args", support.getJavaCommand());
+            String javaCommand = Objects.requireNonNullElse(support.getJavaCommand(), "");
+            properties.setProperty("sun.jvm.args", javaCommand);
             properties.setProperty("sun.jvm.flags", "");
-            properties.setProperty("sun.java.command", support.getJavaCommand());
+            properties.setProperty("sun.java.command", javaCommand);
         }
         return properties;
     }

substratevm/src/com.oracle.svm.core/src/com/oracle/svm/core/jvmstat/SystemCounters.java

@@ -26,6 +26,7 @@
 
 import java.lang.management.ManagementFactory;
 import java.lang.management.ThreadMXBean;
+import java.util.Objects;
 import java.util.concurrent.TimeUnit;
 
 import org.graalvm.nativeimage.ImageSingletons;
@@ -34,14 +35,14 @@
 
 import com.oracle.svm.core.Isolates;
 import com.oracle.svm.core.JavaMainWrapper;
-import com.oracle.svm.guest.staging.Uninterruptible;
 import com.oracle.svm.core.attach.AttachApiSupport;
 import com.oracle.svm.core.heap.Heap;
 import com.oracle.svm.core.imagelayer.ImageLayerBuildingSupport;
 import com.oracle.svm.core.jdk.SystemPropertiesSupport;
 import com.oracle.svm.core.thread.VMOperation;
 import com.oracle.svm.core.thread.VMOperationListener;
 import com.oracle.svm.core.util.BasedOnJDKFile;
+import com.oracle.svm.guest.staging.Uninterruptible;
 import com.sun.management.OperatingSystemMXBean;
 
 /**
@@ -203,7 +204,7 @@ private static long getAvailableProcessors() {
 
     private static String getJavaCommand() {
         JavaMainWrapper.JavaMainSupport support = ImageSingletons.lookup(JavaMainWrapper.JavaMainSupport.class);
-        return support.getJavaCommand();
+        return Objects.requireNonNullElse(support.getJavaCommand(), "");
     }
 
     private static String getVmArgs() {