src/share/classes/java/lang/Throwable.java

@@ -775,11 +775,12 @@
      *
      * @return  a reference to this {@code Throwable} instance.
      * @see     java.lang.Throwable#printStackTrace()
      */
     public synchronized Throwable fillInStackTrace() {
-        if (stackTrace != null) {
+        if (stackTrace != null ||
+            backtrace != null /* Out of protocol state */ ) {
             fillInStackTrace(0);
             stackTrace = UNASSIGNED_STACK;
         }
         return this;
     }

@@ -815,11 +816,12 @@
     }
 
     private synchronized StackTraceElement[] getOurStackTrace() {
         // Initialize stack trace field with information from
         // backtrace if this is the first call to this method
-        if (stackTrace == UNASSIGNED_STACK) {
+        if (stackTrace == UNASSIGNED_STACK ||
+            (stackTrace == null && backtrace != null) /* Out of protocol state */) {
             int depth = getStackTraceDepth();
             stackTrace = new StackTraceElement[depth];
             for (int i=0; i < depth; i++)
                 stackTrace[i] = getStackTraceElement(i);
         } else if (stackTrace == null) {

@@ -863,11 +865,12 @@
             if (defensiveCopy[i] == null)
                 throw new NullPointerException("stackTrace[" + i + "]");
         }
 
         synchronized (this) {
-            if (this.stackTrace == null) // Immutable stack
+            if (this.stackTrace == null && // Immutable stack
+                backtrace == null) // Test for out of protocol state
                 return;
             this.stackTrace = defensiveCopy;
         }
     }