--- a/src/jdk.compiler/share/classes/com/sun/tools/javac/file/Locations.java	Thu Oct 17 20:27:44 2019 +0100
+++ b/src/jdk.compiler/share/classes/com/sun/tools/javac/file/Locations.java	Thu Oct 17 20:53:35 2019 +0100
@@ -94,6 +94,7 @@
 import com.sun.tools.javac.util.Pair;
 import com.sun.tools.javac.util.StringUtils;
 
+import static javax.tools.StandardLocation.SYSTEM_MODULES;
 import static javax.tools.StandardLocation.PLATFORM_CLASS_PATH;
 
 import static com.sun.tools.javac.main.Option.BOOT_CLASS_PATH;
@@ -185,6 +186,12 @@
         return h.isDefault();
     }
 
+    boolean isDefaultSystemModulesPath() {
+        SystemModulesLocationHandler h
+                = (SystemModulesLocationHandler) getHandler(SYSTEM_MODULES);
+        return !h.isExplicit();
+    }
+
     /**
      * Split a search path into its elements. Empty path elements will be ignored.
      *
@@ -226,7 +233,7 @@
     }
 
     public void setMultiReleaseValue(String multiReleaseValue) {
-        fsEnv = Collections.singletonMap("multi-release", multiReleaseValue);
+        fsEnv = Collections.singletonMap("releaseVersion", multiReleaseValue);
     }
 
     private boolean contains(Collection<Path> searchPath, Path file) throws IOException {
@@ -273,7 +280,7 @@
         private static final long serialVersionUID = 0;
 
         private boolean expandJarClassPaths = false;
-        private final Set<Path> canonicalValues = new HashSet<>();
+        private final transient Set<Path> canonicalValues = new HashSet<>();
 
         public SearchPath expandJarClassPaths(boolean x) {
             expandJarClassPaths = x;
@@ -283,7 +290,7 @@
         /**
          * What to use when path element is the empty string
          */
-        private Path emptyPathDefault = null;
+        private transient Path emptyPathDefault = null;
 
         public SearchPath emptyPathDefault(Path x) {
             emptyPathDefault = x;