No longer OOM on invalid string length.

src/factory.cc

Index: src/factory.cc
diff --git a/src/factory.cc b/src/factory.cc
index 5e66202ded50ffeb8047f7c150377cef71423f5b..5c4ac9c5d0da3cbad2dc3a56bbb83f52a1db9905 100644
--- a/src/factory.cc
+++ b/src/factory.cc
@@ -289,7 +289,7 @@ Handle<String> Factory::NewStringFromTwoByte(Vector<const uc16> string,
 
 
 Handle<SeqOneByteString> Factory::NewRawOneByteString(int length,
-                                                  PretenureFlag pretenure) {
+                                                      PretenureFlag pretenure) {
   CALL_HEAP_FUNCTION(
       isolate(),
       isolate()->heap()->AllocateRawOneByteString(length, pretenure),
@@ -411,6 +411,7 @@ Handle<String> Factory::NewConsString(Handle<String> left,
     ASSERT(left->IsFlat());
     ASSERT(right->IsFlat());
 
+    STATIC_ASSERT(ConsString::kMinLength <= String::kMaxLength);
     if (is_one_byte) {
       Handle<SeqOneByteString> result = NewRawOneByteString(length);
       DisallowHeapAllocation no_gc;
@@ -496,12 +497,14 @@ Handle<String> Factory::NewProperSubString(Handle<String> str,
   if (!FLAG_string_slices || length < SlicedString::kMinLength) {
     if (str->IsOneByteRepresentation()) {
       Handle<SeqOneByteString> result = NewRawOneByteString(length);
+      ASSERT(!result.is_null());
       uint8_t* dest = result->GetChars();
       DisallowHeapAllocation no_gc;
       String::WriteToFlat(*str, dest, begin, end);
       return result;
     } else {
       Handle<SeqTwoByteString> result = NewRawTwoByteString(length);
+      ASSERT(!result.is_null());
       uc16* dest = result->GetChars();
       DisallowHeapAllocation no_gc;
       String::WriteToFlat(*str, dest, begin, end);