--- old/src/jdk.jdi/share/classes/com/sun/tools/jdi/JNITypeParser.java	2020-04-12 17:30:16.000000000 -0700
+++ new/src/jdk.jdi/share/classes/com/sun/tools/jdi/JNITypeParser.java	2020-04-12 17:30:16.000000000 -0700
@@ -77,12 +77,12 @@
             index = typeName.indexOf("/");   // check if it's a hidden class
             if (index < 0) {
                 sb.append(typeName.replace('.', '/'));
+                sb.append(";");
             } else {
                 sb.append(typeName.substring(0, index).replace('.', '/'));
-                sb.append(".");
-                sb.append(typeName.substring(index+1, typeName.length()));
+                sb.append(";");
+                sb.append(typeName.substring(index, typeName.length()));
             }
-            sb.append(';');
         }
 
         return sb.toString();
@@ -165,9 +165,15 @@
             case (JDWP.Tag.OBJECT):
                 int endClass = signature.indexOf(SIGNATURE_ENDCLASS,
                                                  currentIndex);
-                String retVal = signature.substring(currentIndex - 1,
-                                                    endClass + 1);
-                currentIndex = endClass + 1;
+                String retVal;
+                if ((endClass+1) < signature.length() && signature.charAt(endClass+1) == '/') {
+                    // hidden class
+                    retVal = signature.substring(currentIndex - 1);
+                    currentIndex = signature.length();
+                } else {
+                    retVal = signature.substring(currentIndex - 1, endClass + 1);
+                    currentIndex = endClass + 1;
+                }
                 return retVal;
 
             case (JDWP.Tag.VOID):
@@ -210,14 +216,14 @@
                                                  currentIndex);
                 String retVal = signature.substring(currentIndex,
                                                     endClass);
-                int index = retVal.indexOf(".");
-                if (index < 0) {
-                    retVal = retVal.replace('/', '.');
+                if ((endClass+1) < signature.length() && signature.charAt(endClass+1) == '/') {
+                    // hidden class
+                    retVal = retVal.replace('/', '.') + signature.substring(endClass + 1);
+                    currentIndex = signature.length();
                 } else {
-                    retVal = retVal.substring(0, index).replace('/', '.') + "/" +
-                             retVal.substring(index + 1, retVal.length());
+                    retVal = retVal.replace('/', '.');
+                    currentIndex = endClass + 1;
                 }
-                currentIndex = endClass + 1;
                 return retVal;
 
             case (JDWP.Tag.FLOAT):