commit eafec6ead2e5a5a5a1b6504311a6a7ec6f0420af
Author: Julian Brown <jbrown@build6-lucid-cs.sje.mentorg.com>
Date:   Wed Jul 25 11:43:08 2012 -0700

    Backtrace through throw.

diff --git a/libstdc++-v3/libsupc++/eh_personality.cc b/libstdc++-v3/libsupc++/eh_personality.cc
index 72f596e..3322b6c 100644
--- a/libstdc++-v3/libsupc++/eh_personality.cc
+++ b/libstdc++-v3/libsupc++/eh_personality.cc
@@ -380,6 +380,8 @@ PERSONALITY_FUNCTION (int version,
   switch (state & _US_ACTION_MASK)
     {
     case _US_VIRTUAL_UNWIND_FRAME:
+      if (state & _US_FORCE_UNWIND)
+	CONTINUE_UNWINDING;
       actions = _UA_SEARCH_PHASE;
       break;