Bugzilla bug #39350: checked in patch from beard@netscape.com. Just

malloc the thread object if GC_LEAK_DETECTOR is defined.  These thread
objects will be leaked.

nsprpub/pr/src/misc/prthinfo.c

@@ -140,19 +140,6 @@ PR_ThreadScanStackPointers(PRThread* t,
         if (status != PR_SUCCESS)
             return status;
     }
-
-#ifdef GC_LEAK_DETECTOR
-    /*
-    ** if the thread was allocated on its own stack, conservatively
-    ** scan the thread object itself to keep all data structures
-    ** referenced by the thread visible to the garbage collector.
-    */
-    if (t->threadAllocatedOnStack) {
-        status = scanFun(t, (void**)t, (sizeof(PRThread) + 3) / sizeof(void*), scanClosure);
-        if (status != PR_SUCCESS)
-            return status;
-    }
-#endif
     
     return PR_SUCCESS;
 }

nsprpub/pr/src/threads/combined/pruthr.c

@@ -1247,6 +1247,14 @@ PR_IMPLEMENT(PRThread*) _PR_CreateThread(PRThreadType type,
             if ((PRUptrdiff)top & 0x3f) {
                 top = (char*)((PRUptrdiff)top & ~0x3f);
             }
+#endif
+#if defined(GC_LEAK_DETECTOR)
+            /*
+             * sorry, it is not safe to allocate the thread on the stack,
+             * because we assign to this object before the GC can learn
+             * about this thread. we'll just leak thread objects instead.
+             */
+            thread = PR_NEW(PRThread);
 #endif
             stack->thr = thread;
             memset(thread, 0, sizeof(PRThread));