Don't crash when preparsing destructured arguments

src/parser.cc

Index: src/parser.cc
diff --git a/src/parser.cc b/src/parser.cc
index 8d180f06a643abb27dbc00ed45474ffc24974fa8..9b8973fd0cf71b35f0391adc598dfe6fef78e341 100644
--- a/src/parser.cc
+++ b/src/parser.cc
@@ -4200,6 +4200,11 @@ FunctionLiteral* Parser::ParseFunctionLiteral(
         materialized_literal_count += formals.materialized_literals_count;
       }
 
+      if (function_state.materialized_literal_count() > 0) {

[caitp (gmail), 2015/09/18 21:30:08]

FunctionState's materialized_literal_count() never returns less than 0, so it
should be okay to get rid of the if block.

[caitp (gmail), 2015/09/18 21:38:16]

In fact, this seems to be true for FormalParameters too, so maybe both the
conditional checks should be taken out?

[adamk, 2015/09/18 23:23:03]

Sounds good, combined into a single statement.

+        materialized_literal_count +=
+            function_state.materialized_literal_count();
+      }
+
       if (bookmark.HasBeenReset()) {
         // Trigger eager (re-)parsing, just below this block.
         is_lazily_parsed = false;