Fixed a problem where stepping out would turn into
a continue if the unwinder didn't unwind correctly.

<rdar://problem/11989668>


git-svn-id: https://llvm.org/svn/llvm-project/lldb/trunk@161086 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/source/Target/Thread.cpp b/source/Target/Thread.cpp
index 5eeaca8..cbd7513 100644
--- a/source/Target/Thread.cpp
+++ b/source/Target/Thread.cpp
@@ -975,8 +975,16 @@
                                                         stop_vote, 
                                                         run_vote, 
                                                         frame_idx));
-    QueueThreadPlan (thread_plan_sp, abort_other_plans);
-    return thread_plan_sp.get();
+    
+    if (thread_plan_sp->ValidatePlan(NULL))
+    {
+        QueueThreadPlan (thread_plan_sp, abort_other_plans);
+        return thread_plan_sp.get();
+    }
+    else
+    {
+        return NULL;
+    }
 }
 
 ThreadPlan *