Merged r11219, r11220, r11236, r11238 into 3.8 branch.

src/execution.cc

Index: src/execution.cc
diff --git a/src/execution.cc b/src/execution.cc
index 71e8ea34a1eb72b2050086889d812afa666c68cd..68d0314b7d0f7525c7c51456a513539848321dec 100644
--- a/src/execution.cc
+++ b/src/execution.cc
@@ -820,6 +820,11 @@ Object* Execution::DebugBreakHelper() {
     return isolate->heap()->undefined_value();
   }
 
+  StackLimitCheck check(isolate);
+  if (check.HasOverflowed()) {
+    return isolate->heap()->undefined_value();
+  }
+
   {
     JavaScriptFrameIterator it(isolate);
     ASSERT(!it.done());
@@ -856,6 +861,11 @@ void Execution::ProcessDebugMessages(bool debug_command_only) {
   // Clear the debug command request flag.
   isolate->stack_guard()->Continue(DEBUGCOMMAND);
 
+  StackLimitCheck check(isolate);
+  if (check.HasOverflowed()) {
+    return;
+  }
+
   HandleScope scope(isolate);
   // Enter the debugger. Just continue if we fail to enter the debugger.
   EnterDebugger debugger;