diff -r 694f6918ba42 -r a6418e038255 hotspot/src/os/windows/vm/os_windows.cpp
--- a/hotspot/src/os/windows/vm/os_windows.cpp	Thu Jul 04 04:03:28 2013 -0700
+++ b/hotspot/src/os/windows/vm/os_windows.cpp	Thu Jul 04 21:10:17 2013 -0700
@@ -1420,34 +1420,40 @@
 
 bool os::dll_address_to_library_name(address addr, char* buf,
                                      int buflen, int* offset) {
+  // buf is not optional, but offset is optional
+  assert(buf != NULL, "sanity check");
+
 // NOTE: the reason we don't use SymGetModuleInfo() is it doesn't always
 //       return the full path to the DLL file, sometimes it returns path
 //       to the corresponding PDB file (debug info); sometimes it only
 //       returns partial path, which makes life painful.
 
-   struct _modinfo mi;
-   mi.addr      = addr;
-   mi.full_path = buf;
-   mi.buflen    = buflen;
-   int pid = os::current_process_id();
-   if (enumerate_modules(pid, _locate_module_by_addr, (void *)&mi)) {
-      // buf already contains path name
-      if (offset) *offset = addr - mi.base_addr;
-      return true;
-   } else {
-      if (buf) buf[0] = '\0';
-      if (offset) *offset = -1;
-      return false;
-   }
+  struct _modinfo mi;
+  mi.addr      = addr;
+  mi.full_path = buf;
+  mi.buflen    = buflen;
+  int pid = os::current_process_id();
+  if (enumerate_modules(pid, _locate_module_by_addr, (void *)&mi)) {
+    // buf already contains path name
+    if (offset) *offset = addr - mi.base_addr;
+    return true;
+  }
+
+  buf[0] = '\0';
+  if (offset) *offset = -1;
+  return false;
 }
 
 bool os::dll_address_to_function_name(address addr, char *buf,
                                       int buflen, int *offset) {
+  // buf is not optional, but offset is optional
+  assert(buf != NULL, "sanity check");
+
   if (Decoder::decode(addr, buf, buflen, offset)) {
     return true;
   }
   if (offset != NULL)  *offset  = -1;
-  if (buf != NULL) buf[0] = '\0';
+  buf[0] = '\0';
   return false;
 }
 
@@ -2689,6 +2695,19 @@
 }
 #endif
 
+#ifndef PRODUCT
+void os::win32::call_test_func_with_wrapper(void (*funcPtr)(void)) {
+  // Install a win32 structured exception handler around the test
+  // function call so the VM can generate an error dump if needed.
+  __try {
+    (*funcPtr)();
+  } __except(topLevelExceptionFilter(
+             (_EXCEPTION_POINTERS*)_exception_info())) {
+    // Nothing to do.
+  }
+}
+#endif
+
 // Virtual Memory
 
 int os::vm_page_size() { return os::win32::vm_page_size(); }