Fix crash in d8 when external array ctor hits stack overflow

src/d8.cc

Index: src/d8.cc
diff --git a/src/d8.cc b/src/d8.cc
index 9eccc7e4fe4ed6fd0786c0bbeb62a06ffb277498..cc91daa692f1cd00e17af640468915f45eeb74a5 100644
--- a/src/d8.cc
+++ b/src/d8.cc
@@ -301,10 +301,26 @@ Handle<Value> Shell::CreateExternalArray(const Arguments& args,
   } else {
     Local<Number> number = args[0]->ToNumber();
     if (number.IsEmpty() || !number->IsNumber()) {
+      i::Isolate* isolate = i::Isolate::Current();
+      if (isolate->try_catch_handler()->HasCaught()) {
+        return isolate->try_catch_handler()->Exception();
+      }
       return ThrowException(String::New("Array length must be a number."));
     }
-    int32_t raw_length = number->ToInt32()->Int32Value();
+    Local<Int32> int32 = number->ToInt32();
+    if (int32.IsEmpty()) {
+      i::Isolate* isolate = i::Isolate::Current();
+      if (isolate->try_catch_handler()->HasCaught()) {
+        return isolate->try_catch_handler()->Exception();
+      }
+      return ThrowException(String::New("Array length must be a number."));

[Rico, 2011/12/13 11:28:39]

we already established that length is a number, so this exception seems wrong.
Can we ever end up here?

[Jakob Kummerow, 2011/12/13 13:04:37]

On second thought, no, we can't. Done.

+    }
+    int32_t raw_length = int32->Int32Value();
     if (raw_length < 0) {
+      i::Isolate* isolate = i::Isolate::Current();
+      if (isolate->try_catch_handler()->HasCaught()) {
+        return isolate->try_catch_handler()->Exception();
+      }
       return ThrowException(String::New("Array length must not be negative."));
     }
     if (raw_length > static_cast<int32_t>(kMaxLength)) {