Do not enter the debugger when debugger is not active.

R=mstarzinger@chromium.org
BUG=
TEST=test-debug/DebuggerCreatesContextIffActive

Review URL: https://chromiumcodereview.appspot.com/10702166

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@12059 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/execution.cc

@@ -832,6 +832,11 @@ Object* Execution::DebugBreakHelper() {
     return isolate->heap()->undefined_value();
   }
 
+  // Ignore debug break if debugger is not active.
+  if (!isolate->debugger()->IsDebuggerActive()) {
+    return isolate->heap()->undefined_value();
+  }
+
   StackLimitCheck check(isolate);
   if (check.HasOverflowed()) {
     return isolate->heap()->undefined_value();

test/cctest/test-debug.cc

@@ -7392,4 +7392,32 @@ TEST(Regress131642) {
   v8::Debug::SetDebugEventListener(NULL);
 }
 
+
+// Import from test-heap.cc
+int CountGlobalContexts();
+
+
+static void NopListener(v8::DebugEvent event,
+                        v8::Handle<v8::Object> exec_state,
+                        v8::Handle<v8::Object> event_data,
+                        v8::Handle<v8::Value> data) {
+}
+
+
+TEST(DebuggerCreatesContextIffActive) {
+  v8::HandleScope scope;
+  DebugLocalContext env;
+  CHECK_EQ(1, CountGlobalContexts());
+
+  v8::Debug::SetDebugEventListener(NULL);
+  CompileRun("debugger;");
+  CHECK_EQ(1, CountGlobalContexts());
+
+  v8::Debug::SetDebugEventListener(NopListener);
+  CompileRun("debugger;");
+  CHECK_EQ(2, CountGlobalContexts());
+
+  v8::Debug::SetDebugEventListener(NULL);
+}
+
 #endif  // ENABLE_DEBUGGER_SUPPORT

test/cctest/test-heap.cc

@@ -984,7 +984,7 @@ TEST(TestCodeFlushing) {
 
 
 // Count the number of global contexts in the weak list of global contexts.
-static int CountGlobalContexts() {
+int CountGlobalContexts() {
   int count = 0;
   Object* object = HEAP->global_contexts_list();
   while (!object->IsUndefined()) {